Peptide ChooserPeptides for libido: what is approved, and what is not.
Short answer
Bremelanotide (Vyleesi) is FDA approved for premenopausal women with low sexual desire that causes distress and has no other cause.1 PT-141 is the same molecule, bremelanotide, sold by research-use shops without a prescription; that is not the approved product.23 Melanotan II is not approved for any use, and its nomination for pharmacy compounding was withdrawn.4
Which peptides are sold for libido?
Our libido page lists three:
- Bremelanotide (Vyleesi): FDA approved. A shot you take before sex, approved for low sexual desire in premenopausal women.
- PT-141 from online shops: Not an approved product. The same molecule as Vyleesi, sold without a prescription by research-use shops: no dose control, no checks.
- Melanotan II: Not approved for any use. A tanning peptide also sold "for libido". Linked to serious side effects; never approved anywhere.
What is Vyleesi approved for?
Bremelanotide, sold as Vyleesi, is approved for premenopausal women with acquired, generalized hypoactive sexual desire disorder: low sexual desire that causes marked distress or trouble in the relationship, and is not caused by another medical or mental health condition, problems in the relationship or a medicine.1
It is not approved for men, for women after menopause or to boost desire in people without that condition.1
What did the trials find?
Two identical trials gave 1,267 premenopausal women bremelanotide or a placebo for 24 weeks, without them knowing which. Women on bremelanotide reported a small but clear rise in desire and less distress about low desire than women on the placebo.6
More of them had nausea, flushing and headache: each came up in 10% or more of the women on bremelanotide in both trials.6 The trials were paid for by the companies that make it.6
What does the Vyleesi label warn about?
- Blood pressure rises for a short time and heart rate drops after each dose, usually for less than 12 hours. It is not for people with uncontrolled high blood pressure or known heart disease.1
- Nausea is common: 40% of patients in the studies reported it.1
- About 1% had dark patches on the skin, for example on the face or gums, and in some they did not go away.1
A prescriber checks these before and during treatment. A shop vial comes with none of that.
Is PT-141 the same as Vyleesi?
The molecule is the same: PT-141 was the research name of bremelanotide.2 The product is not. A PT-141 vial from a research-use shop is not the approved medicine: nobody checked how it was made, how much is in it or whether it is clean, and it comes without a prescriber.7
What about Melanotan II?
Melanotan II is a tanning peptide that is also sold for libido. It is not approved for any use.3 Our database records that its nomination for pharmacy compounding was withdrawn.4
The FDA says it may set off an immune reaction when given some ways, and that published case reports describe serious side effects, including melanoma, a brain swelling syndrome, an overdose-like reaction and painful erections that do not go away.4
What do they cost?
60 shops we track list Bremelanotide (Vyleesi); the middle price across their listings is $4.05 per mg.5 59 shops we track list Melanotan II; the middle price across their listings is $3.50 per mg.5 The shop listings are research-use vials, not Vyleesi.
The windows on our libido page list each shop with its five checks; we never link to the shops. A price per mg says nothing about what is in the vial.
So which peptide works for libido?
Only one has trials in people and FDA approval: bremelanotide as Vyleesi, for one group of women with one condition.1 The same molecule from a shop is a different product, and Melanotan II has serious case reports behind it and no approval.
If low desire troubles you, a doctor can first look for the causes the Vyleesi label rules out: another health problem, the relationship or a medicine you take.1
None of this is medical advice. A doctor can tell you what fits you.
What to do next
Sources
- FDA drug label for Vyleesi (bremelanotide), Indications and Usage, through openFDA, effective 13 Nov 2025: https://api.fda.gov/drug/label.json?search=openfda.brand_name:%22VYLEESI%22
- Diamond LE et al., Bremelanotide (PT-141), a melanocortin receptor agonist, in premenopausal women, J Sex Med 3(4), 2006, PubMed 16839319: https://pubmed.ncbi.nlm.nih.gov/16839319/
- Drugs@FDA, searched through openFDA for BPC-157, GHK-Cu (also as copper tripeptide and prezatide) and TB-500 (also as thymosin beta-4): no approved product, 2 Nov 2026: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm
- FDA, Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks, current as of 22 Apr 2026: https://www.fda.gov/drugs/human-drug-compounding/certain-bulk-drug-substances-use-compounding-may-present-significant-safety-risks
- Peptide Chooser database: the research-use and cosmetic peptide shops we check, 2 Nov 2026. Their prices and checks are in the seller windows on our goal pages
- Kingsberg SA et al., Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials, Obstet Gynecol 134(5), 2019, PubMed 31599840: https://pubmed.ncbi.nlm.nih.gov/31599840/
- FDA, Development and Approval Process: Drugs: https://www.fda.gov/drugs/development-approval-process-drugs