Pinc PeptideThe girly peptide research blog

Sexual health · 4 compounds · updated 8 October 2026

Best peptides for libido, ranked by the human evidence

4 compounds are sold for libido and sexual health. We rank them by how strong the evidence in people is, not by popularity. 3 of the 4 are FDA-approved for some use; the rest are not.

Bremelanotide, sold as Vyleesi, was tested in two large trials in 1,267 women with low desire before menopause1. From each woman’s start to her last visit (week 24 for those who finished), desire scores rose 0.30 and 0.42 points more than on placebo, on a scale from 1.2 to 612. Its label says it is not for women after menopause, for men or for enhancing sexual performance2. Kisspeptin’s libido trials were small UK studies that gave one 75-minute drip of kisspeptin-54, the longer form, to 32 men and 32 women with low desire; the trial in women measured brain activity, not desire or sex at home34. Sellers mostly offer kisspeptin-10, a shorter form, and kisspeptin’s effect fades with frequent or nonstop dosing5678. Oxytocin nasal spray, sold for intimacy, did no better than placebo over 8 weeks in 30 women with sexual problems, and one dose in 29 couples left desire and arousal unchanged910. Gonadorelin, a lab-made copy of the brain hormone GnRH, is given by some prescribers to men on testosterone in place of hCG, but we found no published trial of it in men on testosterone therapy111213. Its fertility results come from pumps giving a pulse every 90 minutes to people whose brains make too little GnRH1415.

On 24 August 2026, FDA warned five online sellers that the ‘PT-141’ they sold was an unapproved new drug, and in June 2026 it told another seller the same about its ‘research’ gonadorelin161718192021. Whether US pharmacies may make bremelanotide is unclear, but they may not make kisspeptin: FDA lists it as a significant safety risk, and its advisers voted 0 to 11 against it in October 20242223242526. By our reading, they can probably make gonadorelin on prescription, because federal law lets them use an ingredient that meets a USP standard and USP publishes one for gonadorelin acetate, but FDA has not said so2627. Kisspeptin and gonadorelin are banned in sport at all times for male athletes, while bremelanotide is not on the banned list2829. Independent tests are uneven: Finnrick, a testing service, failed 53 of 151 PT-141 samples from March 2025 to September 2026 but lists only two kisspeptin tests, from April and August 2026, both incomplete, and none of gonadorelin303132. People choose which samples to send, so the results are not a random survey33. A vial labeled PT-141 that WIRED bought at a Brooklyn bodega held no PT-141 (reported 15 September 2026)34.

  1. Oxytocin

    AMixed resultsApproved as Pitocin; sprays and vials are not

    Oxytocin is a pituitary hormone approved in the US as Pitocin, a hospital injection for labor and bleeding after birth35. Nasal sprays sold for bonding, calm and libido rest on mostly small trials with mixed results93637.

    Does it work for bonding, mood, anxiety and libido? Trials disagree: one dose eased anxiety in a lab stress test, but sprays did not beat placebo for women’s sexual problems or social anxiety, and a large repeat study found no rise in trust9373839.

  2. PT-141 (bremelanotide)

    AMixed resultsApproved as Vyleesi; vials are not

    PT-141 is bremelanotide, approved in the US as Vyleesi for low sexual desire in women before menopause240. It helps a little, nausea is common, and ‘PT-141’ vials sold online are not approved1216.

    Does it work for low sexual desire in women and men? Two large trials in women before menopause found slightly more desire than placebo, but not more frequent satisfying sex1. In men, the one large erection trial we found is under a journal’s expression of concern414243.

  3. Kisspeptin

    BMixed resultsNot approved for any use

    Kisspeptin is a natural hormone that switches on the body’s reproductive system544. In brief human studies it raised sex hormones and arousal measures345, but it is not approved for any use and US pharmacies may not make it522.

    Does it work for sex drive and testosterone? One drip of the longer form changed brain and arousal responses in people with low desire34. The short form sold online raises hormones in short studies, but no published trial tests home use5845.

  4. Gonadorelin

    BUntestedApproved for cattle; human brands discontinued

    Gonadorelin is a lab-made copy of the brain hormone that tells the pituitary gland to switch on the testes and ovaries4647. Pump pulses helped women ovulate, but we found no published trial of it in men on testosterone therapy111214.

    Does it work for keeping testes working during testosterone therapy? We found no trial of it in men on testosterone therapy1112. Its fertility benefits came from pump pulses every 90 minutes in people lacking the hormone, not from injections a few times a week154748.

How we ranked them

Compounds that trials show work for this goal come first, then those with mixed results, then those with no controlled human trial for this goal that has public results, and last those that trials found do not work. Within each group, the stronger the human evidence (tier A to E), the higher the place. Ties go to compounds FDA has approved as a medicine, then to those approved only in other countries, then to those whose US approval was withdrawn, then to peptides over non-peptide drugs, then to the winner of a trial that compared the two directly. Popularity, price and how a product is marketed play no part. A high place is not a recommendation to use anything.

How we grade evidence →

Head-to-head

Doses used in studies

Further reading

Questions people ask

Do peptides increase libido?

Slightly, in women with low desire before menopause, the group studied in bremelanotide’s two large trials1. Distress about low desire fell 0.37 and 0.29 points more than on placebo on a 0 to 4 scale, but the number of satisfying sexual events did not differ, and among women whose answer was recorded, about 58% on the drug rated it as beneficial against 36% on placebo1.

Is there a libido peptide for men?

Neither bremelanotide nor kisspeptin is approved for men25. Bremelanotide caused erections in small early lab studies, but work in men was halted after FDA questioned its benefit and called blood pressure increases its greatest safety concern in 2007; a 2008 trial in 342 men is under a journal’s expression of concern, and we found no results from a study announced in 2024424349505152. In 32 men with low desire, one drip of kisspeptin-54 increased penile swelling during sexual videos by up to 56% more than placebo3.

Are libido peptides safe?

Bremelanotide’s label reports nausea in 40% of women in its large trials and a rise in blood pressure after each dose, and frequent use can darken skin: 1% at up to 8 doses a month, but 38% after 8 daily doses24053. Kisspeptin’s safety with regular use is unknown: FDA counted about 300 people given kisspeptin-10 in small, short studies, and in mice prone to clogged arteries, 4 weeks of it sped plaque growth554.

Sources

  1. 1Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials Obstetrics & Gynecology, Nov 2019. pubmed.ncbi.nlm.nih.gov
  2. 2VYLEESI (bremelanotide injection) prescribing information Cosette Pharmaceuticals via DailyMed (U.S. National Library of Medicine), 13 Nov 2025. dailymed.nlm.nih.gov
  3. 3Effects of Kisspeptin on Sexual Brain Processing and Penile Tumescence in Men With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial JAMA Network Open, 1 Feb 2023. pubmed.ncbi.nlm.nih.gov
  4. 4Effects of Kisspeptin Administration in Women With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial JAMA Network Open, 3 Oct 2022. pubmed.ncbi.nlm.nih.gov
  5. 5FDA Briefing Document, Pharmacy Compounding Advisory Committee meeting of October 29, 2024: kisspeptin-10 (FDA evaluation dated 5 July 2024) U.S. Food and Drug Administration, 5 Jul 2024. fda.gov
  6. 6Unauthorized health products sold online and seized at Rize Fitness may pose serious health risks (RA-81403) Health Canada, 24 Dec 2025. recalls-rappels.canada.ca
  7. 7Subcutaneous injection of kisspeptin-54 acutely stimulates gonadotropin secretion in women with hypothalamic amenorrhea, but chronic administration causes tachyphylaxis The Journal of Clinical Endocrinology & Metabolism, Nov 2009. pubmed.ncbi.nlm.nih.gov
  8. 8Chronic subcutaneous kisspeptin-10 stimulates gonadotropin secretion for 12 days in healthy men European Journal of Endocrinology, 3 Aug 2026. pubmed.ncbi.nlm.nih.gov
  9. 9Effect of long-term intranasal oxytocin on sexual dysfunction in premenopausal and postmenopausal women: a randomized trial Fertility and Sterility, Sep 2015. pubmed.ncbi.nlm.nih.gov
  10. 10Differential effects of intranasal oxytocin on sexual experiences and partner interactions in couples Hormones and Behavior, Mar 2014. pubmed.ncbi.nlm.nih.gov
  11. 11PubMed search: gonadorelin with testosterone or TRT in the title or abstract (24 results; none gave gonadorelin to men taking testosterone) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
  12. 12ClinicalTrials.gov search for ‘gonadorelin AND “testosterone replacement”’ (3 records, none giving gonadorelin to men on testosterone) ClinicalTrials.gov, accessed 8 Oct 2026. clinicaltrials.gov
  13. 13Compounded Gonadorelin in Men’s Health Empower Pharmacy (vendor), 7 Mar 2024. empowerpharmacy.com (seller page, deliberately not linked)
  14. 14LutrePulse Hypogonadotropic Hypogonadism (NCT01976728), registry record with results ClinicalTrials.gov, 3 Mar 2021. clinicaltrials.gov
  15. 15The Pulsatile Gonadorelin Pump Induces Earlier Spermatogenesis Than Cyclical Gonadotropin Therapy in Congenital Hypogonadotropic Hypogonadism Men American Journal of Men’s Health, 2019. pubmed.ncbi.nlm.nih.gov
  16. 16Warning letter to Peak Performance Peptides (MARCS-CMS 735127) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  17. 17Warning letter to Royal Peptides LLC (MARCS-CMS 734884) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  18. 18Warning letter to NuScience Peptides LLC (MARCS-CMS 733652) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  19. 19Warning letter to Peptide Partners LLC (MARCS-CMS 735063) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  20. 20Warning letter to TXP Innovations LLC dba Tex Peptides (MARCS-CMS 735067) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  21. 21Warning letter to Wholesale Peptide (MARCS-CMS 729447) U.S. Food and Drug Administration, 17 Jun 2026. fda.gov
  22. 22Bulk Drug Substances Nominated for Use in Compounding Under Section 503A of the Federal Food, Drug, and Cosmetic Act (categories list) U.S. Food and Drug Administration, 14 May 2026. fda.gov
  23. 23Certain Bulk Drug Substances for Use in Compounding that May Present Significant Safety Risks U.S. Food and Drug Administration, 22 Apr 2026. fda.gov
  24. 24Final Summary Minutes of the Pharmacy Compounding Advisory Committee Meeting, October 29, 2024 U.S. Food and Drug Administration, 15 Jan 2025. fda.gov
  25. 25Drugs@FDA record for NDA 210557 (Vyleesi), openFDA drugsfda endpoint U.S. Food and Drug Administration (openFDA), 29 Sep 2026. api.fda.gov · data query
  26. 26Bulk Drug Substances Used in Compounding Under Section 503A of the FD&C Act U.S. Food and Drug Administration, 14 May 2026. fda.gov
  27. 27USP Monographs: Gonadorelin Acetate (USP-NF, 2025 revision) United States Pharmacopeia, 2025. doi.usp.org
  28. 28World Anti-Doping Code International Standard: Prohibited List 2026 World Anti-Doping Agency, 24 Sep 2025. wada-ama.org
  29. 29World Anti-Doping Code International Standard: Prohibited List 2027 World Anti-Doping Agency, 21 Sep 2026. wada-ama.org
  30. 30Kisspeptin: safety testing results and vendor ratings Finnrick, 3 Aug 2026. finnrick.com
  31. 31PT-141 Safety Testing Results & Vendor Ratings Finnrick, accessed 8 Oct 2026. finnrick.com
  32. 32Finnrick public data summary (llms-full.txt, generated 25 September 2026) Finnrick, 25 Sep 2026. finnrick.com
  33. 33We’d Rather Buy the Future Than Wait For It Finnrick, 10 Jun 2026. finnrick.com
  34. 34Those Viral Bodega Peptides Aren’t Actually Peptides WIRED, 15 Sep 2026. wired.com
  35. 35PITOCIN (oxytocin injection, USP) prescribing information Par Health USA, LLC via DailyMed (U.S. National Library of Medicine), 21 May 2026. dailymed.nlm.nih.gov
  36. 36Statistical and Methodological Considerations for the Interpretation of Intranasal Oxytocin Studies Biological Psychiatry, 1 Feb 2016. pubmed.ncbi.nlm.nih.gov
  37. 37A registered replication study on oxytocin and trust Nature Human Behaviour, Jun 2020. pubmed.ncbi.nlm.nih.gov
  38. 38A randomized controlled trial of intranasal oxytocin as an adjunct to exposure therapy for social anxiety disorder Psychoneuroendocrinology, Jul 2009. pubmed.ncbi.nlm.nih.gov
  39. 39Social support and oxytocin interact to suppress cortisol and subjective responses to psychosocial stress Biological Psychiatry, 15 Dec 2003. pubmed.ncbi.nlm.nih.gov
  40. 40NDA 210557 Multi-discipline Review and Evaluation (bremelanotide) U.S. Food and Drug Administration, CDER, Jun 2019. accessdata.fda.gov
  41. 41Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study The Journal of Urology, Mar 2008. pubmed.ncbi.nlm.nih.gov
  42. 42Expression of Concern: Salvage of Sildenafil Failures With Bremelanotide: A Randomized, Double-Blind, Placebo Controlled Study The Journal of Urology, 10 Jan 2023. pubmed.ncbi.nlm.nih.gov
  43. 43PubMed search: (bremelanotide OR “PT-141” OR “PT 141”) AND (erectile OR men OR male), limited to clinical trials and randomized controlled trials (6 results on 8 October 2026; the only large trial is a 2008 trial of 342 men under an expression of concern) National Library of Medicine (PubMed), accessed 8 Oct 2026. pubmed.ncbi.nlm.nih.gov
  44. 44The GPR54 gene as a regulator of puberty New England Journal of Medicine, 23 Oct 2003. pubmed.ncbi.nlm.nih.gov
  45. 45Kisspeptin-10 is a potent stimulator of LH and increases pulse frequency in men The Journal of Clinical Endocrinology & Metabolism, Aug 2011. pubmed.ncbi.nlm.nih.gov
  46. 46A Multicenter, Double-Blind, Randomized, Placebo-Controlled Study Evaluating Three Doses of Subcutaneous Pulsatile GnRH Administered via OmniPod Pump: clinical trial protocol, amendment 7 (NCT01976728) Ferring Pharmaceuticals, via ClinicalTrials.gov, 6 Dec 2017. cdn.clinicaltrials.gov
  47. 47LUTREPULSE (gonadorelin acetate) product monograph Ferring Inc. via Health Canada Drug Product Database, 17 May 2016. pdf.hres.ca
  48. 48Gonadorelin: How It Works, Mechanism & Evidence (2026) The Peptide Catalog, 30 Jul 2026. thepeptidecatalog.com
  49. 49Evaluation of the safety, pharmacokinetics and pharmacodynamic effects of subcutaneously administered PT-141, a melanocortin receptor agonist, in healthy male subjects and in patients with an inadequate response to Viagra International Journal of Impotence Research, Apr 2004. pubmed.ncbi.nlm.nih.gov
  50. 50King Pharmaceuticals and Palatin Technologies delay immediate plans for Phase 3 clinical program with bremelanotide for erectile dysfunction (Form 8-K, Exhibit 99) Palatin Technologies via SEC EDGAR, 30 Aug 2007. sec.gov
  51. 51Double-blind, placebo-controlled evaluation of the safety, pharmacokinetic properties and pharmacodynamic effects of intranasal PT-141, a melanocortin receptor agonist, in healthy males and patients with mild-to-moderate erectile dysfunction International Journal of Impotence Research, Feb 2004. pubmed.ncbi.nlm.nih.gov
  52. 52Palatin Announces the Initiation of a Phase 2 Clinical Study of Bremelanotide Co-Administered with a PDE5i for the Treatment of Erectile Dysfunction (ED) Palatin Technologies, 20 Jun 2024. palatin.com
  53. 53Effect of bremelanotide on body weight of obese women: Data from two phase 1 randomized controlled trials Diabetes, Obesity and Metabolism, Jun 2022. pmc.ncbi.nlm.nih.gov
  54. 54Potent Vasoconstrictor Kisspeptin-10 Induces Atherosclerotic Plaque Progression and Instability: Reversal by its Receptor GPR54 Antagonist Journal of the American Heart Association, 14 Apr 2017. pubmed.ncbi.nlm.nih.gov

Not medical advice. Each compound page cites its sources for every claim above. All compounds in one table · Report an error.