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PEPTIDE READER

Brain, mood & sex

Peptides for libido and sexual function

Three entries, and they sit as far apart as this register gets.

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 barely2 peptides
  4. Only tested on animalsnone on this page
  5. No real evidence at allnone on this page
How we grade evidence

One is an approved prescription medicine, licensed in the United States for low sexual desire in premenopausal women and tested against a dummy injection in more than a thousand of them; the effect is real, it is small, and a published re-analysis argues that participants preferred the placebo. The other two are approved nowhere. One is sold online as a tanning injection, where the erections were found along the way and the entire tanning evidence is three men. The other is a hormone the body already makes, studied almost entirely by a single research group. Everything measured on this page comes from a questionnaire about how a person felt, which is the only instrument there is for this and is not the same kind of number as a blood test.

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

    PT-141

    Bremelanotide · Vyleesi

    Approved for low sexual desire that causes distress, in women who have not been through the menopause.

    Two large randomised trials found a real but small gain in desire and a drop in distress, while the number of satisfying sexual encounters did not change.

    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.

2 peptides

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

    Kisspeptin

    Kisspeptin-54 · Kisspeptin-10

    Promoted for libido, fertility and testosterone, and sold as a compounded injection.

    It shifts reproductive hormones within minutes, but the one placebo-controlled course lasting weeks failed to raise testosterone.

    Sold as: Gray market

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

    Melanotan II

    Melanotan 2 · MT-II

    Sold online as a tanning injection, and separately as something that produces erections.

    Two placebo-controlled studies in 20 men found it produces erections; the tanning evidence is one pilot in three men, and the harms are single case reports.

    Sold as: Gray market