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PEPTIDE READER

Recovery & strength

Peptides for the immune system and inflammation

Three entries, and the distance between them is the point.

The evidence mix

The 3 peptides on this page, by how well they have been tested.

  1. Approved medicine1 peptide
  2. Still being tested in peoplenone on this page
  3. Tested in people, but barely1 peptide
  4. Only tested on animals1 peptide
  5. No real evidence at allnone on this page
How we grade evidence

One is a real prescription medicine, approved in Italy since the 1990s for one narrow use — as a helper for the flu jab in people whose immune system is weak — while what it is actually famous for has been tested and mostly failed: in 1,106 adults with sepsis, deaths within 28 days were 23.4 per cent on the drug against 24.1 per cent on dummy injections, and the immune marker it is supposed to raise did not move. The second is a copy of a peptide the body itself makes, with one properly controlled trial behind it and a published harm signal sitting alongside the benefit one. The third has never been given to a person in a published study at all. An immune system is not a dial that reads high or low, and nothing on this page has shown it can be turned in a chosen direction and left there.

All 3 peptides on this page

Strongest evidence first.

Filter these in the full register

Approved medicine

Approved by the European or US medicines regulator for a named condition, after large randomised trials, with a public product information sheet anyone can read.

1 peptide

  1. Evidence level 5 of 5: Approved medicine

    Thymosin alpha-1

    Thymalfasin · Thymalfasinum

    Approved in Italy only as a helper for flu vaccination in adults with a weak immune system, and promoted far more widely for immunity, inflammation, long COVID and ageing.

    The largest trial, in 1,106 adults with sepsis, matched dummy injections on every outcome including the immune marker the drug is supposed to raise.

    Sold as: Therapeutic

Tested in people, but barely

Human studies exist, but they are small, short, uncontrolled, paid for by the seller, or they measure something easy to measure instead of something that matters.

1 peptide

  1. Evidence level 3 of 5: Tested in people, but barely

    LL-37

    Cathelicidin LL-37 · cathelicidin antimicrobial peptide

    Sold online for infections, wound healing and gut problems; a peptide the body makes itself.

    The one properly controlled trial, in 148 people with leg ulcers, closed no more wounds than a dummy gel.

    Sold as: Gray market

Only tested on animals

The evidence is animal experiments, cells in a dish, or computer models. No meaningful controlled trial in humans has been published.

1 peptide

  1. Evidence level 2 of 5: Only tested on animals

    KPV

    KPV peptide · Lys-Pro-Val

    Sold for gut inflammation, skin conditions and wound healing.

    No published study has ever given it to a person; the evidence is mouse, rat and rabbit experiments and cells in dishes.

    Sold as: Gray market