Does glutathione actually whiten skin?

A little, sometimes, on the parts of you that see the sun, and the studies do not agree. In a four-week trial in 60 people, the pigment reading fell further on glutathione than on dummy capsules at two of six measured spots. In a twelve-week trial in 60 women it did not beat dummy capsules anywhere in the group as a whole. In a third twelve-week trial in 83 Indonesian adults, paid for by the company that makes the capsule, nothing it measured came out significantly different from placebo. Nothing published shows the dramatic change these products are sold as.

Are glutathione IV drips safe?

No medicines regulator has approved any injectable product for lightening skin, and the Philippine regulator has warned the public against these drips by name. Its 2019 advisory lists toxic effects on the liver, the kidneys and the nervous system, the risk of a severe blistering skin reaction, and — where a drip is given by someone who is not a medical practitioner or somewhere that is not sterile — HIV and hepatitis passed on through the needle. A published review of the one trial of the injections reports liver problems in about a third of the people treated and severe allergic shock in one.

Is oral glutathione absorbed, or is it a waste of money?

A single dose is essentially not absorbed as glutathione: the gut lining and the liver carry an enzyme that cuts it apart, and after a 3 g dose in seven healthy adults, nothing measurable had reached the blood four and a half hours later. Daily capsules are a different question, and there the answer is less bleak — after six months of 250 mg or 1,000 mg a day, the glutathione stored inside people's blood cells and cheek cells was 17% to 260% above where each of them had started, depending on the dose and the tissue. A month after stopping, it was all back to baseline.

Glutathione vs NAC — which one actually raises glutathione?

They work from opposite ends. Glutathione capsules deliver the finished molecule, most of which is dismantled before it arrives. NAC — N-acetylcysteine — delivers the scarce building block and lets your own cells assemble the rest, which is why hospitals use it rather than glutathione for paracetamol poisoning. In a randomised trial in 24 older adults, sixteen weeks of NAC combined with the amino acid glycine raised glutathione inside cells against a dummy supplement. That is 12 people per group, so it is a small trial, not a settled comparison, and no trial has ever put the two head to head for skin.

Is glutathione banned in sport?

The substance is not on the World Anti-Doping Agency's 2026 Prohibited List — the word glutathione does not appear anywhere in it. The drip can still get an athlete banned, though, and for a reason that has nothing to do with what is in the bag: section M2.2 of that list prohibits intravenous infusions or injections of more than 100 mL in total per 12 hours, except when they are legitimately part of hospital treatment, surgery or a diagnostic test. A skin-whitening drip in a salon is none of those things.

Can you buy glutathione legally?

The capsules, yes — glutathione is sold across Europe and the US as an ordinary food supplement, which means nobody had to prove it works before it went on sale. The injections are a different matter. No approved medicine containing glutathione exists in the United States: a search of the US regulator's own approved-products database returns no match for it as an active substance. Injectable glutathione is authorised in some countries for narrow medical uses — the Philippine regulator says its own approval there covers use alongside cisplatin chemotherapy — and in none of them for lightening skin.

What are the side effects of glutathione?

From the capsules, in trials of up to six months: mild stomach upset, itching, small bumps, spots and tiredness, at about the same rate as on dummy capsules — 9% against 8% in one trial, 5 of 38 against 4 of 19 in another. Two of 60 women in a twelve-week trial were withdrawn because their liver blood tests rose. From the drip, the reported list is much worse and much less measured: severe allergic shock, liver problems, kidney and nerve effects, a blistering skin reaction that peels the skin off, and infections passed on by the needle. Nobody has counted how often any of those happen, because no trial has been large enough or long enough to count them.

Is glutathione good for anti-ageing?

One arm of one trial found less fine wrinkling on the sun-protected inner arm after twelve weeks on 250 mg a day than on dummy capsules, and skin springiness drifted upwards without reaching statistical significance. That trial had 57 people in it, was paid for by the company that makes the ingredient, and has not been repeated. Nothing published follows anyone past six months, and no trial has measured anything about ageing beyond instrument readings of skin.

Supplement

Glutathione

Also known as GSH · L-glutathione · reduced glutathione · gamma-glutamylcysteinylglycine · γ-Glu-Cys-Gly · Glutathione (INCI) · CAS 70-18-8 · PubChem CID 124886 · gluta · gluta drip · glutathione IV · glutathione drip · glutathione injection · glutathione whitening pills · glutathion · gluthathione · glutatione · glutathaione

Tested in people, but barely

23 of 55 peptides sit at this level

Category: Supplement
Doping status: Not banned in sport
Sources: 22

Glutathione is a small molecule every cell in your body already makes, and it is sold two very different ways: as a swallowed supplement, and as a drip into a vein in beauty clinics, mainly across Asia, to lighten skin. Swallowed, most of it is taken apart in the gut before it reaches the blood — a 3 g dose moved nothing measurable in seven healthy adults. The skin-lightening trials are small, short, run mostly in Asia, and disagree with each other: one found a difference against dummy capsules at two of six measured spots, one found none overall, and a third, paid for by the supplement's maker, found nothing at all. The drip is the part with no evidence and the reported harm: the Philippine medicines regulator has warned the public against it by name, and no injectable product is approved anywhere for lightening skin.

GlutathioneWhat it is

What it is
Sold and legal
In your body
What changed
What can go wrong
Amounts studied
What people say
Unknowns
Questions
Sources

What it is

A three-part molecule that every cell in your body already makes, from glutamate, cysteine and glycine, and the body's main internal antioxidant. It is not made from a gene the way a protein is — two enzymes assemble it — so there is no gene sequence anywhere to check it against. It is sold two very different ways. As capsules, lozenges and powders it is an ordinary food supplement, taken for skin, ageing and "detox". As an infusion into a vein it is sold in salons, spas and beauty clinics, mainly across Asia, to lighten skin, and that use is not approved by any medicines regulator anywhere.

How it is sold, and whether it is legal

Sold as: Swallowed, as capsules, powder, or a lozenge dissolved in the mouth. Applied to the skin in creams and lotions. Infused into a vein in beauty clinics, which is the form regulators warn about.
Legal status in the EU: Sold in the EU as a food supplement under Directive 2002/46/EC, a framework that requires no proof that an ingredient works before it goes on sale. Under Regulation (EC) No 1924/2006 a supplement may carry only health claims from the EU's authorised list, and it may not be marketed as having medical effects. A search of the European Medicines Agency's medicine finder on 4 August 2026 returned no glutathione medicine; EMA lists only medicines it evaluated centrally, so an authorisation granted nationally in a single member state would not show up there and we could not rule one out. In the United States there is no approved drug product containing it: a search of the regulator's own approved-products database for glutathione as an active substance returns no match. Injectable glutathione is authorised in some countries for narrow medical purposes — the Philippine regulator states that its own approval covers use alongside cisplatin chemotherapy — and in none of them for lightening skin. That regulator issued a public advisory on 5 July 2019 warning against the intravenous drips offered by salons, spas and beauty clinics, stating that no injectable product is approved for skin lightening and that there are no published clinical trials of the practice.

What it does in your body

5 parts of the body · 1 where studies in people disagree, 3 from one small study, 1 only seen in a dish

The reason anyone expected it to lighten skin comes from laboratory work on the cells that make pigment. Glutathione interferes with the single key enzyme that builds pigment, partly by grabbing the copper atom that enzyme needs at its working end, and it pushes the assembly line towards the pale reddish-yellow kind of pigment instead of the dark brown-black kind. That is a redirection rather than a shutdown: the skin keeps making pigment, it just makes a lighter sort. Two published reviews raise the same corollary — the dark kind is what absorbs ultraviolet light — as a theoretical reason to worry about sun damage in someone whose skin was protecting them, and nobody has studied it. The other half of the mechanism story is what happens before any of that. The molecule is held together at an unusual point: the first link runs from a carboxyl group on the glutamate's side branch, the gamma position, rather than from the main one, which is why it resists the enzymes that chew ordinary peptides apart from the end. It does not resist the enzyme that cuts precisely at that link, and the lining of the small intestine and the liver are both rich in it — which is why a swallowed dose is largely dismantled before it arrives. PubChem gives C10H17N3O6S and 307.33 g/mol for CID 124886.

Skin colour: This is what almost everyone takes it for, and it is where the studies contradict each other. Skin darkness is measured with a small probe held against the skin, which reads out a number for how much pigment is in it. In one four-week trial the number fell in everyone taking glutathione, but only beat the dummy capsule at two of the six places it was measured. In a twelve-week trial at half the amount, the numbers drifted lower than placebo everywhere and reached statistical significance nowhere — except in one slice of the group, women over 40, at one sun-exposed spot on the forearm. In a third trial, of a glutathione capsule sold as a product, the difference against placebo was not significant on any of its main measurements. The pattern that survives all three is that any effect is small, shows up on sun-exposed skin rather than covered skin, and is nowhere near the transformation the products are sold as.; Three randomised, double-blind, placebo-controlled trials: 60 medical students in Bangkok over 4 weeks at 500 mg a day; 60 women in Thailand over 12 weeks at 250 mg a day, funded by Kyowa Hakko Bio, which also supplied the capsules; and 83 of 90 Indonesian adults over 12 weeks on a combination capsule, funded by Mazta Farma, which makes it. A fourth trial, in 124 Asian women, tested glutathione on its own against a combination with another amino acid and against placebo, and found the combination beat all of them — its abstract does not report whether glutathione alone beat placebo, and the paper is paywalled.; Studies in people disagree; Source [02]Source [03]Source [04]
The gut and the bloodstream, in the hours after you swallow it: This is the central question about glutathione and it has an unfriendly answer. The lining of the small intestine and the liver both carry an enzyme that snips glutathione apart at exactly the link that holds it together, so most of a swallowed dose never arrives in the blood as glutathione. When seven healthy adults were given a single large dose and their blood was watched for four and a half hours, the amount of glutathione circulating did not rise measurably above where each of them had started. Neither did the two building blocks it would break into. The authors concluded that how much of a swallowed dose reaches the bloodstream is, in their word, negligible.; One study in 7 healthy volunteers, given 0.15 mmol per kilogram of body weight in a single dose — about 3 g for an average adult — with blood sampled over 270 minutes. There was no dummy-dose group; each person was compared with their own level before swallowing it. Their starting blood glutathione averaged 6.2 micromoles per litre. The same finding is restated as the starting point of later work on formulations designed to bypass the gut.; One small study; Source [01]Source [16]
The body's own stores, over months of taking it: The single-dose result is not the whole story. When people kept taking capsules every day for half a year, the amount of glutathione held inside their blood cells, their immune cells and the cells lining the inside of the cheek went up compared with where each of them had started. The rise was bigger on the larger daily amount than the smaller one, and bigger the longer people took it. It was also completely temporary: a month after stopping, the readings had fallen back to where they began. So daily intake appears to top something up without any single dose being absorbed intact — but this rests on one trial of 54 people, and it measures a laboratory reading, not anything a person would notice.; One randomised, double-blind, placebo-controlled trial in 54 non-smoking adults over 6 months, at 250 mg or 1,000 mg a day. Read the comparison carefully: the published abstract reports the increases in glutathione against each person's own starting level, not against the placebo group. The only figure it gives against placebo is an immune measurement in a subgroup. The full paper is behind a paywall, so nothing from inside it — including who paid for it — is stated here.; One small study; Source [05]
Wrinkles and how springy the skin is: The same twelve-week trial that failed to move skin colour did find something on wrinkles. A camera-based instrument reading the fine roughness of the skin came out lower on glutathione than on dummy capsules at one measured site — the inside of the arm, which is not exposed to sun. Springiness drifted upwards on both glutathione and its oxidised twin, and did not reach statistical significance, meaning the drift is within what chance produces. This is one arm of one trial of 57 people, on a machine reading, and it has not been repeated by anyone.; One randomised, double-blind, placebo-controlled trial: 60 healthy women randomised, 57 completing, 250 mg a day for 12 weeks. Three stopped early — two because their liver blood tests rose, one because she started the contraceptive pill. The wrinkle finding was at the sun-protected left arm, p = 0.006. The company that makes the ingredient paid for the study and supplied it.; One small study; Source [03]
The cells that make pigment, in the laboratory: The reason anyone thought this would lighten skin comes from dishes, not people. Pigment is built by one key enzyme, and glutathione interferes with it in two ways at once: it grabs the copper atom the enzyme needs at its working end, and it pushes the assembly line towards the pale reddish-yellow kind of pigment instead of the dark brown-black kind. That second part is a redirection rather than a shutdown — the skin keeps making pigment, it just makes a lighter sort. Two review articles point out the same uncomfortable corollary: the dark kind is what absorbs ultraviolet light, so shifting away from it in someone whose skin was protecting them is a theoretical reason to worry about sun damage. Nobody has followed anyone long enough to find out.; Laboratory work on the pigment-making enzyme and on pigment cells, summarised in two published reviews. No study in a person has measured the shift between the two kinds of pigment in living skin, and no study of any length has looked at skin cancer risk.; Only seen in a dish, not in a body; Source [07]Source [13]

What changed when it was measured

8 findings · all from one small study

A 12-week placebo-controlled trial of a marketed glutathione capsule found nothing: in 83 Indonesian adults, sun-related spots, visible spots and skin tone all moved further on a 500 mg glutathione capsule than on placebo, and none of those differences was statistically significant, with p-values from 0.440 to 0.904 — and the company that makes the capsule paid for it (Sitohang and colleagues, J Clin Aesthet Dermatol 2021; NCT04105504). The two trials that did find something found small, patchy effects. Arjinpathana and Asawanonda (J Dermatolog Treat 2012) gave 500 mg a day to 60 medical students for 4 weeks: the pigment reading fell at all six measured spots and beat dummy capsules at two of them, the right side of the face (p = 0.021) and the sun-exposed left forearm (p = 0.036). Weschawalit and colleagues (Clin Cosmet Investig Dermatol 2017) gave 250 mg a day to 60 women for 12 weeks and found no significant difference from placebo on pigment across the group at all — only in the over-40 slice, at one sun-exposed forearm site (p = 0.031) — while fine wrinkling at the sun-protected arm did come out lower (p = 0.006); that trial was funded by Kyowa Hakko Bio, which also supplied the capsules. Underneath all of it sits the absorption problem: after a single 3 g dose in 7 healthy adults, blood glutathione did not rise measurably above each person's own pre-dose level over four and a half hours (Witschi and colleagues, Eur J Clin Pharmacol 1992). Six months of daily capsules did raise the body's stores — 17% to 260% depending on dose and tissue, against each person's own baseline — and a month after stopping they were back where they started (Richie and colleagues, Eur J Nutr 2015, 54 adults). The intravenous whitening drips, which is what most of the money is spent on, have essentially no evidence at all: a 2016 review searching the literature to September 2015 found no study of the practice, and the single placebo comparison a 2025 systematic review could find did not reach statistical significance. The sequence field is deliberately empty. Glutathione is glutamate, cysteine and glycine, so the one-letter code a reader expects is "ECG" — but that code means three ordinary peptide bonds, and glutathione's first bond runs from the glutamate's side branch instead. PubChem's chemical name for CID 124886 puts the link at position 5 of the glutamate chain and leaves position 1 free, which is that gamma linkage written out. "ECG" would name a different molecule, so nothing is printed.

Nothing happens in the blood in the hours after a swallowed dose — that is the finding of the one study that looked. Everything else is slow and short-lived. The lozenge study reported the pigment reading starting to fall by two weeks, but it had no comparison group, so two weeks is when the number moved, not when it beat anything. The trials that did have a comparison group ran 4 weeks and 12 weeks. Body stores rose at 1, 3 and 6 months of daily capsules and were back to their starting level one month after stopping, which is the clearest statement anyone has of how long an effect lasts: not past the last capsule. Six months is the longest any published trial has run. There is no published data on a second year, and none at all on what happens to someone who has drips for years, which is how the whitening clinics sell them.

Glutathione in the blood after one large swallowed dose: No measurable rise. Over the four and a half hours after the dose, blood glutathione, and both of the building blocks it would break down into, did not increase significantly from each person's own level before swallowing it. The authors' conclusion was that it is not possible to raise circulating glutathione to a useful degree with a single 3 g dose by mouth.; 7 healthy volunteers, single dose of 0.15 mmol per kilogram of body weight, blood sampled over 270 minutes, each person compared with their own pre-dose level; One small study; Source [01]
Glutathione held inside the body's cells after six months of daily capsules: On 1,000 mg a day, up 30–35% in red blood cells, in the liquid part of the blood and in one type of immune cell, and up 260% in cells swabbed from the inside of the cheek, all against each person's own starting level. On 250 mg a day, up 17% in whole blood and 29% in red blood cells. A month after stopping, the readings were back where they started. The published abstract does not report these rises against the placebo group.; 54 non-smoking adults, 250 mg or 1,000 mg a day, 6 months, plus a 1-month washout; One small study; Source [05]
Skin darkness on 500 mg a day for four weeks: The pigment reading fell at all six measured spots on glutathione. It fell significantly further than on dummy capsules at two of those six: the right side of the face (p = 0.021) and the sun-exposed left forearm (p = 0.036). At the other four spots the difference between the two groups was not statistically significant, which means it is within what chance produces.; 60 otherwise healthy medical students in Bangkok, all 60 completing, 4 weeks; One small study; Source [02]
Skin darkness on 250 mg a day for twelve weeks: Not significantly different from dummy capsules. The pigment reading and the count of sun spots tended lower than placebo at every site measured on the face and the arm, on both the ordinary and the oxidised form of glutathione, and no comparison reached statistical significance across the whole group. One slice did: among women over 40, the sun-exposed right forearm read lower on glutathione than on placebo (p = 0.031). A result found by cutting a 57-person trial into age groups is a lead, not a finding.; 60 healthy women randomised, 57 completing — 20 on glutathione, 18 on its oxidised form, 19 on placebo — 12 weeks; funded by the ingredient's manufacturer; One small study; Source [03]
Facial spots and overall skin tone on a 500 mg glutathione capsule for twelve weeks: No significant difference from placebo on anything the trial set out to measure. Sun-related spots, visible spots and skin tone all moved further in the glutathione group than the placebo group, and none of those differences was statistically significant; the reported p-values ran from 0.440 to 0.904. The authors' own summary is that the supplement was slightly beneficial in particular subgroups but that the results were not statistically significant.; 90 Indonesian adults aged 33 to 50 randomised across three teaching hospitals, 83 completing, 12 weeks, on a capsule of 500 mg L-glutathione with vitamin C, alpha-lipoic acid and zinc; funded by the company that makes it; One small study; Source [04]Source [17]
Fine wrinkling of the skin on 250 mg a day for twelve weeks: Lower on glutathione than on dummy capsules at the sun-protected left arm (p = 0.006), and lower again in the over-40 slice of the group (p = 0.043). Skin springiness drifted up on both forms of glutathione and the difference from placebo did not reach statistical significance.; 57 healthy women completing a 12-week randomised placebo-controlled trial; One small study; Source [03]
How hard one kind of immune cell attacks its targets: More than twice as high on 1,000 mg a day as on placebo at 3 months (p < 0.05). This is the one measurement in that trial the published abstract reports against the placebo group rather than against each person's own baseline. It was measured in a subgroup, not in everyone, and it is a laboratory test, not a count of anyone getting fewer infections.; A subset of the 54 adults in the 6-month trial; One small study; Source [05]
Skin lightening from glutathione injected into a vein: One placebo-controlled comparison exists in the published literature and it did not reach statistical significance. A 2025 systematic review reports it as 6 of 16 people responding (37.5%) against 3 responding (18.7%) in the comparison group, p = 0.054. A separate review of the same trial in 2018 described its design as dubious, its analysis as apparently flawed, its dropout rate as high and its rating scale as unreliable, and concluded that its results did not favour the injections. A 2016 review searching the medical literature to September 2015 found no study of intravenous glutathione for skin lightening at all.; As reported in the 2025 review, which is paywalled; the primary trial is in a journal this register could not open, so only what these reviews state appears here; One small study; Source [07]Source [10]Source [11]

What can go wrong

6 effects, 5 serious

From the capsules, over the four to twenty-six weeks anyone has studied, the picture is unremarkable: mild stomach upset, itching, small bumps, spots and tiredness, at about the same rate as on dummy capsules — 9% against 8% in the Indonesian trial (p = 0.546), and 5 of 38 on either form of glutathione against 4 of 19 in the Thai one. Two of the 60 women randomised in that Thai trial were withdrawn because their liver blood tests rose, and the report does not say which arm they were in. The injections are where the harm is reported and where nothing has been counted. The Philippine regulator's 2019 advisory lists toxic effects on the liver, the kidneys and the nervous system, the risk of the severe blistering reaction called Stevens-Johnson syndrome, and — where the drip is given by someone who is not a medical practitioner, or somewhere that is not sterile — HIV and hepatitis B and C passed on through the needle. A 2018 review of the single published trial of the drips reports liver problems in about a third of those treated and severe allergic shock in one person. A 2021 case report ties toxic epidermal necrolysis, the worst form of that blistering reaction, to whitening pills containing glutathione. Two reviews raise a further theoretical concern that has never been studied: shifting the skin towards the lighter kind of pigment removes some of its own ultraviolet protection. Nothing has been published on pregnancy, on breastfeeding, on children, on any use beyond six months, or on what is actually in a vial bought online.

A severe, blistering skin reaction that peels the skin offSerious: This is the reaction doctors call Stevens-Johnson syndrome at its milder end and toxic epidermal necrolysis at its worst. The skin blisters and comes away in sheets, and the mouth and eyes are usually involved. The 2021 case report is behind a paywall; its title states that whitening pills containing glutathione caused the severe form and that the culprit was confirmed with two laboratory methods, and nothing further from inside it is reported here.; Not measured. Nobody has counted how often this happens, because there is no trial long enough or large enough to count it in. It appears in the Philippine medicines regulator's warning as a named concern, and in a published case report of a person who took whitening pills containing glutathione.; Source [06]Source [12]
A sudden severe allergic reactionSerious: One person went into severe allergic shock in the small trial of glutathione given into a vein, as reported by a review of it. A drip delivers the whole dose into the bloodstream in minutes, which is why an allergic reaction to an injected substance can escalate faster than one to a swallowed one. Two published reviews of the injections name this as a leading safety concern.; Not measured in any trial. In the US regulator's public database of food, supplement and cosmetic complaints there are 29 reports naming a product branded glutathione in the whole database. Five of them use the term for an allergic reaction and four use the term for the sudden, life-threatening kind. Twenty-nine reports is far too few to be a safety record of anything, and the agency says plainly that a report is not evidence the product caused anything.; Source [11]Source [18]Source [19]
Liver blood tests going the wrong waySerious: Liver blood tests are markers, not symptoms — none of these people were described as ill. The awkward part is the direction: glutathione is given in hospitals partly for liver problems, so a signal pointing the other way in a cosmetic trial is worth watching rather than dismissing. The 32% figure comes from a review of the injection trial, not from a paper this register could open.; In the 12-week trial of 250 mg a day, 2 of the 60 women randomised were taken off the study because their liver blood tests rose; the report does not say which arm they were in. In the small trial of the injections, a review of it reports liver problems in 32% of the people treated.; Source [03]Source [11]
Infections and air in the bloodstream from the drip itselfSerious: This risk has nothing to do with glutathione and everything to do with putting a needle into a vein. The regulator lists transmission of HIV and of hepatitis B and C; a review of the practice adds air entering the bloodstream and blood poisoning from unsterile technique. Skin-lightening drips are frequently sold in salons and spas rather than clinics, which is exactly the setting the warning is about.; Not counted anywhere. The Philippine medicines regulator names it as a particular concern where the drip is given by someone who is not a medical practitioner, or in premises that are not sterile.; Source [06]Source [11]
Kidney and nerve problems after injectionsSerious: There is a second problem hiding here. The drips are commonly sold with high-dose vitamin C in the same bag, and the regulator warns separately about that: large amounts of vitamin C can form kidney stones when the urine is acidic, and in people with a common inherited enzyme deficiency called G6PD deficiency, large doses have caused red blood cells to break down badly enough to need dialysis. A person who has a bad time on a whitening drip has no way of knowing which ingredient did it.; Not measured. The Philippine regulator lists toxic effects on the kidneys and on the nervous system among the side effects of injectable glutathione used for skin lightening. It gives no rate, because no study has counted one.; Source [06]
Mild stomach upset, itching, rash and tiredness from the capsules: The complaints recorded were feeling sick, small bumps on the skin, itching, spots, pain at the top of the stomach, redness and tiredness. In both trials the placebo group reported them at a similar or higher rate, which is the useful comparison and the reason the swallowed form is generally described as well tolerated over these lengths of time. Nobody has followed a person taking it for longer than six months.; About as common as on dummy capsules. In the 12-week Indonesian trial, 9% of the glutathione group and 8% of the placebo group reported mild effects in the first four weeks (p = 0.546). In the 12-week Thai trial, 5 of the 38 people on either form of glutathione (13.15%) reported something against 4 of 19 on placebo (21.05%).; Source [03]Source [04]

Who it is known to be dangerous for

Nothing here has been established the way it is established for a licensed medicine, and that absence is itself the answer for one group: nobody should be receiving this into a vein for cosmetic reasons. No medicines regulator anywhere has approved an injectable product for lightening skin, the Philippine regulator has issued a public warning naming glutathione drips specifically, and two published reviews found no adequate trial of the practice. That warning applies with particular force where the drip is given by someone who is not a medical practitioner or in premises that are not a clinic. Beyond that, the honest list is short because the studies are short. Everyone in every trial named here was an adult; no published trial has enrolled a child, and nothing has been published on pregnancy or breastfeeding. Anyone who has ever reacted badly to a glutathione product should treat a severe blistering skin reaction as the reason to stay away, since a case report ties one to whitening pills. And anyone with the inherited enzyme deficiency called G6PD deficiency has a specific reason to avoid the drips, which are usually mixed with high-dose vitamin C — a combination that has sent people with that deficiency to dialysis.

The amounts the studies used

7 amounts

These are the amounts the studies below gave their participants, and they are here as facts about those studies. They are not a recommendation, not a starting point and not a range to pick from. What a person should take, if anything, is a question for a doctor who knows them.

Witschi et al. 1992, whether a swallowed dose reaches the bloodstream at all: A single dose of 0.15 mmol per kilogram of body weight, swallowed — about 3 g for an average adult; One dose, with blood sampled for 270 minutes afterwards; Source [01]
Arjinpathana and Asawanonda 2012, skin darkness in 60 medical students: 500 mg a day in two divided doses, as capsules, against identical dummy capsules; 4 weeks; Source [02]
Weschawalit et al. 2017, skin darkness, wrinkles and springiness in 60 women — three arms, one for each form: 250 mg a day of ordinary glutathione, or 250 mg a day of the oxidised form, against dummy capsules of dibasic calcium phosphate; 12 weeks; Source [03]
Richie et al. 2015, what daily intake does to the body's stores — the longest trial there is: 250 mg a day or 1,000 mg a day, against dummy capsules; 6 months, followed by a 1-month period off it; Source [05]
Sitohang et al. 2021, the Indonesian trial of a marketed capsule: One capsule a day containing 500 mg L-glutathione made by fermentation, 250 mg vitamin C, 50 mg alpha-lipoic acid and zinc as zinc aspartate, against dummy capsules; 12 weeks; Source [04]
Handog et al. 2016, a lozenge dissolved in the mouth to bypass the gut, in 30 Filipino women — no comparison group at all: One glutathione lozenge daily; 8 weeks; Source [20]
The one published trial of the drip, as described by a 2018 review of it — the primary report is in a journal this register could not open: 1,200 mg into a vein twice a week; 6 weeks in the trial; the review notes no standard duration exists in practice; Source [11]

What people report

What follows is what people say online. It is not evidence, it is not graded, and it is not checked by anyone. People who had a bad time and people who are selling something both post more than people for whom nothing happened. It is here because you would go and read it anyway, and knowing who is talking is better than not.

Most people who want lighter skin want it badly, and the drip is what they are offered

In a published survey at a clinic in Hyderabad, 150 of 223 transgender women (67.3%) said they were interested in skin-lightening treatment, and 65 of the 223 (29.1%) had actually used something. Sixteen of them had used glutathione given into a vein, more than had used any other single named product. The authors' own comment on that is that the injections are popular and expensive and their effectiveness is questionable.

Read in A survey of 223 hijra and transgender women at the Mitr Clinic in Hyderabad, India, published in JMIR Dermatology in 2025

What the published studies say

Every placebo-controlled trial with a result in it used capsules, not a drip. The one placebo comparison for the injections that a 2025 systematic review could find did not reach statistical significance, and a 2016 review searching to September 2015 found no study of the practice at all.

The complaints that reach a regulator are allergic ones, not disappointment

In the US regulator's public database of complaints about foods, supplements and cosmetics, there are 29 reports in total naming a product branded glutathione. Counting the same term written in different cases as one, the terms used most are allergic reaction (5 reports), rash (5), feeling sick (4), the sudden severe kind of allergic reaction (4) and shortness of breath (4).

Read in The openFDA food, dietary supplement and cosmetic adverse event reporting system, searched on 4 August 2026

What the published studies say

In the two placebo-controlled trials that counted side effects, the placebo groups reported them at a similar or higher rate — 8% against 9%, and 4 of 19 against 5 of 38. Twenty-nine voluntary reports in a database covering an entire country is too few to be a safety record, and the agency says a report is not evidence the product caused anything.

People stop long before any trial would have measured anything

The survey authors record that they did not collect how long people used products for, and say so as a limitation. What is visible instead is the shape of the market: treatments bought a session or a bottle at a time, in salons and clinics, on recommendations from friends, relatives and sellers.

Read in The same survey of 223 people in Hyderabad, whose authors state that data on individual product costs and usage durations were not collected

What the published studies say

In the one trial that followed body stores over time, everything that had risen over six months was back to its starting level one month after the last capsule. There is no published evidence of anything persisting after someone stops.

Where to read it yourself

openFDA food, supplement and cosmetic side-effect reports (CAERS)
Official side-effect reports
The US regulator's public database of complaints and side-effect reports about foods, dietary supplements and cosmetics, searchable by product name. Supplement manufacturers have to forward serious reports; everyone else reports voluntarily.
The agency states plainly that a report is not evidence the product caused anything, that the reports are unvalidated and often duplicated, and that only a small fraction of what happens is ever reported. For glutathione the specific trap is size: 29 reports in the entire database for a substance sold in tens of millions of capsules. Nothing can be inferred from a number that small except which kinds of complaint people bothered to file.
Survey of skin-lightening practices among hijra and transgender women in Hyderabad (JMIR Dermatology, 2025)
Published survey of users
A published questionnaire given to 300 hijra and transgender women attending one clinic in Hyderabad, in Hindi, Telugu or English, asking what skin-lightening treatments they wanted, what they had used and what they paid; 223 of them answered the skin-lightening questions. It is one of the few places where what people actually buy — including the injections — is written down and counted rather than assumed.
Everyone in it came through a single clinic and was asked consecutively, so it describes that clinic's population and not a country. The authors say the questionnaire had not been tested for reliability beforehand, that they could not measure income accurately because most of the work was informal, and that they did not collect how long anyone used anything for. It is also a survey of a marginalised group under specific social pressure to lighten their skin, which is part of what it measures and not a flaw in it.

What nobody has measured

17 unknowns

Whether any of it works for skin colour at all — three placebo-controlled trials of the capsules disagree, and the largest and most recent of them found nothing.
Whether anyone can see the change the probe measures; no trial has asked a person, or anyone looking at them, whether they could tell.
Whether the drip does anything: the one placebo comparison anyone has published did not reach statistical significance, and its primary report is in a journal this register could not open.
How much glutathione a drip actually delivers to skin, and for how long — no published study has measured it in a person having one.
Whether pushing the skin towards the lighter kind of pigment raises the risk of sun-induced skin cancer, which two reviews raise as a theoretical concern and nobody has studied.
What happens after six months, which is the longest any published trial has run.
What happens to people who have drips for years, which is how clinics sell them.
Whether anything persists after stopping: the one trial that measured it found body stores back at their starting level within a month.
Whether the raised body stores mean anything for health, as opposed to being a laboratory reading that moved.
Whether the immune measurement that doubled against placebo in a subgroup of 54 people corresponds to anyone getting fewer infections.
Whether the two women taken off a trial for raised liver blood tests were on glutathione or on placebo — the report does not say.
Whether it is safe in pregnancy or breastfeeding, and whether it does anything in children; no published trial has enrolled either.
Whether it interacts with any medicine.
How often the severe reactions listed by the Philippine regulator actually happen, since no study has been large enough to count them.
How much of the drips' reported harm comes from glutathione and how much from the high-dose vitamin C usually mixed into the same bag.
What is in a vial bought online, since no independent analysis of the products actually sold for whitening has been published.
Whether any of the trials that found an effect would replicate outside the company that paid for them — the ingredient's manufacturer funded two of the three placebo-controlled skin trials named here.

Questions people ask

8 questions

Does glutathione actually whiten skin?: A little, sometimes, on the parts of you that see the sun, and the studies do not agree. In a four-week trial in 60 people, the pigment reading fell further on glutathione than on dummy capsules at two of six measured spots. In a twelve-week trial in 60 women it did not beat dummy capsules anywhere in the group as a whole. In a third twelve-week trial in 83 Indonesian adults, paid for by the company that makes the capsule, nothing it measured came out significantly different from placebo. Nothing published shows the dramatic change these products are sold as.; Source [02]Source [03]Source [04]
Are glutathione IV drips safe?: No medicines regulator has approved any injectable product for lightening skin, and the Philippine regulator has warned the public against these drips by name. Its 2019 advisory lists toxic effects on the liver, the kidneys and the nervous system, the risk of a severe blistering skin reaction, and — where a drip is given by someone who is not a medical practitioner or somewhere that is not sterile — HIV and hepatitis passed on through the needle. A published review of the one trial of the injections reports liver problems in about a third of the people treated and severe allergic shock in one.; Source [06]Source [07]Source [11]
Is oral glutathione absorbed, or is it a waste of money?: A single dose is essentially not absorbed as glutathione: the gut lining and the liver carry an enzyme that cuts it apart, and after a 3 g dose in seven healthy adults, nothing measurable had reached the blood four and a half hours later. Daily capsules are a different question, and there the answer is less bleak — after six months of 250 mg or 1,000 mg a day, the glutathione stored inside people's blood cells and cheek cells was 17% to 260% above where each of them had started, depending on the dose and the tissue. A month after stopping, it was all back to baseline.; Source [01]Source [05]
Glutathione vs NAC — which one actually raises glutathione?: They work from opposite ends. Glutathione capsules deliver the finished molecule, most of which is dismantled before it arrives. NAC — N-acetylcysteine — delivers the scarce building block and lets your own cells assemble the rest, which is why hospitals use it rather than glutathione for paracetamol poisoning. In a randomised trial in 24 older adults, sixteen weeks of NAC combined with the amino acid glycine raised glutathione inside cells against a dummy supplement. That is 12 people per group, so it is a small trial, not a settled comparison, and no trial has ever put the two head to head for skin.; Source [01]Source [21]
Is glutathione banned in sport?: The substance is not on the World Anti-Doping Agency's 2026 Prohibited List — the word glutathione does not appear anywhere in it. The drip can still get an athlete banned, though, and for a reason that has nothing to do with what is in the bag: section M2.2 of that list prohibits intravenous infusions or injections of more than 100 mL in total per 12 hours, except when they are legitimately part of hospital treatment, surgery or a diagnostic test. A skin-whitening drip in a salon is none of those things.; Source [09]
Can you buy glutathione legally?: The capsules, yes — glutathione is sold across Europe and the US as an ordinary food supplement, which means nobody had to prove it works before it went on sale. The injections are a different matter. No approved medicine containing glutathione exists in the United States: a search of the US regulator's own approved-products database returns no match for it as an active substance. Injectable glutathione is authorised in some countries for narrow medical uses — the Philippine regulator says its own approval there covers use alongside cisplatin chemotherapy — and in none of them for lightening skin.; Source [06]Source [14]Source [22]
What are the side effects of glutathione?: From the capsules, in trials of up to six months: mild stomach upset, itching, small bumps, spots and tiredness, at about the same rate as on dummy capsules — 9% against 8% in one trial, 5 of 38 against 4 of 19 in another. Two of 60 women in a twelve-week trial were withdrawn because their liver blood tests rose. From the drip, the reported list is much worse and much less measured: severe allergic shock, liver problems, kidney and nerve effects, a blistering skin reaction that peels the skin off, and infections passed on by the needle. Nobody has counted how often any of those happen, because no trial has been large enough or long enough to count them.; Source [03]Source [04]Source [06]
Is glutathione good for anti-ageing?: One arm of one trial found less fine wrinkling on the sun-protected inner arm after twelve weeks on 250 mg a day than on dummy capsules, and skin springiness drifted upwards without reaching statistical significance. That trial had 57 people in it, was paid for by the company that makes the ingredient, and has not been repeated. Nothing published follows anyone past six months, and no trial has measured anything about ageing beyond instrument readings of skin.; Source [03]Source [05]

Sources

22 sources

Skin · Ageing & lifespan

23 peptides · strongest evidence first