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D2C Peptides

Research goal

Peptides and men's health

Most results on this page come from small, short studies; the largest body of evidence is for prescription hormone therapy in men with hypogonadotropic hypogonadism, which produced sperm in 75% of men who had none across 44 studies.10 Studies of peptides for erections and libido are mostly small, and none of those peptides is approved for erectile dysfunction.131415161718 This page maps what people search as peptides for men and what published sources report on each; it makes no promise, and testosterone has its own page.

This page summarizes published sources for information only. It is not medical advice and does not tell anyone to use a product. Questions about your own health belong with a licensed clinician. For questions about an order or a product, contact us.

What "peptides for men" covers

Searches for "peptides for men" mix three different questions: fertility, sexual function, and growth hormone or body composition. Testosterone itself is mapped on Peptides and testosterone. This page covers the rest, plus what the labels of approved weight and diabetes medicines say about men.

Fertility and sperm production

HCG

In a retrospective series of 26 hypogonadal men taking testosterone plus hCG, none became azoospermic (no sperm in semen) and 9 contributed to a pregnancy.2122 The label lists sporadic breast enlargement and occasional fluid retention after high doses,23 and hCG is contraindicated with prostate cancer or other androgen-dependent tumors.24 hCG is a prescription drug, and the prescriber sets the dose.23 Read What is HCG? or see HCG for sale.

HMG

HMG's US label covers only women, but in the UK, Menopur is licensed for men with hypogonadotrophic hypogonadism, given with hCG to start sperm production.2526 Men with primary testicular failure usually do not respond.26 In a 1985 study, adding HMG to hCG normalized sperm counts in 5 of 7 men whose condition began before puberty and who had no history of undescended testes.27 The US label says it should be used only by physicians experienced in infertility treatment, and the prescriber sets the dose.25 Read What is HMG? or see HMG for sale.

Gonadorelin

In a nonrandomized study of 28 men with congenital hypogonadotropic hypogonadism, the 10 on a gonadorelin pump started making sperm sooner than the 18 on hCG plus HMG (median 6 against 14 months).28 Semen usually stays below normal WHO values with either approach.11 WADA bans gonadorelin for male athletes at all times.29 Read What is Gonadorelin? or see Gonadorelin for sale.

Testagen

Fertility claims for Testagen rest on a developer report: partly preserved fertility in irradiated rats, and, in a report on 48 men, sperm counts that rose from 16 to 22 million/mL after a 20-day course of oral capsules.30 None of this has been independently replicated, and PubMed lists no peer-reviewed human study of Testagen.3031 Read What is Testagen? or see Testagen for sale.

Erections and sexual desire

PT-141

PT-141 is bremelanotide, which FDA approved as Vyleesi for premenopausal women with acquired, generalized low sexual desire; the label states it is not indicated for low sexual desire in men, and the prescriber sets the dose.17 The studies in men are small trials, mostly of a nasal form, that showed erectile responses, a 19-man study with sildenafil, and a 2008 trial of 342 men that carries a 2023 expression of concern.32143334 A 2026 journal article still asks whether it should be considered for men.35 The full picture is on PT-141 and men's health. Read What is PT-141? or see PT-141 for sale.

Melanotan 2

In a double-blind crossover study of 20 men with erectile dysfunction, Melanotan 2 led to erections in 17 without sexual stimulation and raised desire, but nausea and yawning were frequent.133637 It is not FDA approved for any use, and priapism has been reported.1638 Read What is Melanotan 2? or see Melanotan 2 for sale.

Kisspeptin-10

In one trial of 32 men with hypoactive sexual desire disorder, a single 75-minute intravenous infusion of kisspeptin-54, a longer form than kisspeptin-10, increased penile tumescence to sexual stimuli and "happiness about sex" compared with placebo, with no side effects reported.1539 It ran at one UK research center.39 Read What is Kisspeptin-10? or see Kisspeptin-10 for sale.

Vilon

In old male rats, Vilon activated sexual function and lowered prolactin; there are no human data on sexual function.40 Read What is Vilon? or see Vilon for sale.

Growth hormone peptides, studied mostly in men

Most human data for these peptides come from men.4142 The sections below show what those studies did and did not measure.

CJC-1295

Of the 63 healthy adults in the three published CJC-1295 studies, all given the DAC version, 87% were men, and two of the three studies enrolled only men aged about 20 to 40.434441 A 2026 review of peptides in sexual medicine found that growth hormone secretagogues reliably raise GH and IGF-1, but evidence for better sexual function, physical performance or quality of life is limited.45 No study reviewed here tested CJC-1295 without DAC for libido or sexual health, and FDA found no pharmacology studies of that form at all.4546 Profiles: CJC-1295 with DAC, CJC-1295 No DAC and CJC-1295 + Ipamorelin. Vials: CJC-1295 with DAC for sale, CJC-1295 No DAC for sale and CJC-1295 + Ipamorelin for sale.

GHRP-6

Most adult human GHRP-6 studies enrolled only men: 17, 18, 9, 9, 9 and 5 healthy men in six separate studies,474849505152 so the adult human data mostly describe men. In them, IV GHRP-6 raised growth hormone, a 34-hour infusion raised IGF-1, and prolactin and cortisol about doubled at the highest single dose tested.474849 Read What is GHRP-6? or see GHRP-6 for sale.

Sermorelin

A retrospective review of 14 younger men already on testosterone found higher IGF-1 after a sermorelin, GHRP-2 and GHRP-6 combination was added.5354 Its trial results in older men are in the questions below. Read What is Sermorelin? or see Sermorelin for sale.

Tesamorelin

Tesamorelin (Egrifta WR) is FDA-approved only to reduce excess abdominal fat in adults with HIV and lipodystrophy, and the prescriber sets the dose.68 In its first phase 3 trial, 86% of participants were men.42 In 13 healthy men, 2 weeks of treatment raised growth hormone and IGF-1 without significantly changing fasting glucose or insulin sensitivity.555657 Read What is Tesamorelin? or see Tesamorelin for sale.

HGH

In a 26-week randomized trial in older men, growth hormone raised lean mass by 3.1 kg;58 the side effects seen in the same trial are in the questions below. Read What is HGH? or see HGH for sale.

Other compounds with data in men

MOTS-c

In 27,527 adults of Japanese descent, men but not women who carried the K14Q variant of MOTS-c had more type 2 diabetes,59 and healthy middle-aged and older men had lower blood MOTS-c than young men.60 These are associations, not results of taking MOTS-c. Read What is MOTS-c? or see MOTS-c for sale.

SS-31

Barth syndrome, the only approved use of SS-31 (as Forzinity, under accelerated approval), mainly affects males, and all 12 patients in its pivotal trial were male.6162 None of the human trials reviewed measured testosterone or sexual function.63 Read What is SS-31? or see SS-31 for sale.

What approved medicine labels say about men

Tirzepatide: Mounjaro and Zepbound

The Mounjaro label reports no effect of tirzepatide on sperm shape, mating or fertility in male rats, and effectiveness did not differ by gender in its trials.64 On Zepbound, hair loss was much less common in men than in women (0.5% against 7.1%).65 Most participants in its sleep apnea trials were men (67% and 72%).66 Read What is Mounjaro?, What is Zepbound? or What is Tirzepatide?.

Semaglutide: Rybelsus

The Rybelsus label reports no clinically significant differences in semaglutide levels by sex, and its effect on blood sugar did not differ by sex; in rats, semaglutide had no effect on male fertility.67 Read What is Rybelsus? or What is Semaglutide?.

How to read this research

Being studied mostly in men is not the same as being shown to help men: the CJC-1295 studies enrolled mostly men but measured only hormone levels and short-term side effects.41 The fertility results come from men with a diagnosed pituitary or hypothalamic condition, not from men with normal hormone levels.1110 Some findings carry a warning flag: the largest PT-141 trial in men has an expression of concern,34 and the Testagen data come only from its developers.30 For approved medicines, the label lists who the drug is for, and the prescriber sets the dose. The linked profiles carry each compound's full regulatory status and sources.

Compound by compound

  • PT-141 and men's health

    What published sources report on PT-141 and men's health, with links to the PT-141 profile and the men's health hub.

Other research goals

Frequently asked questions

What are the benefits of sermorelin for men?

The studies are small and short. In 10 older men, two weeks at the higher of two doses raised growth hormone and IGF-1 to the levels of young men.12 In an uncontrolled 6-week study of 11 men aged 64 to 76, 2 of 6 strength measures improved, and body composition did not change.34 These trials measured hormones, strength and body composition, not long-term health. The approved sermorelin product, Geref, was discontinued, and FDA withdrew its approval in 2009.5

What are the potential side effects of HGH in men?

In a 26-week randomized trial of older men, 41% of those given growth hormone had joint pain, and carpal tunnel symptoms affected 32% of men given growth hormone plus testosterone.6 Diabetes or glucose intolerance was also more common with growth hormone (18 against 7 men).7 In a review of healthy older adults, breast enlargement (gynecomastia) was more common with growth hormone.8 Somatropin is a prescription drug, and the prescriber sets the dose.9

Can peptides help male fertility?

Hormone treatments can start sperm production in men with hypogonadotropic hypogonadism, whose pituitary or hypothalamus does not drive the testes: a 2014 meta-analysis of 44 studies in such men with no sperm found that gonadotropin therapy produced sperm in 75%.10 In the congenital form, pulsed GnRH and gonadotropin therapy each start sperm production in about 75% to 80% of men, although semen usually stays below normal values.11 The Endocrine Society recommends against starting testosterone in men planning fertility in the near term.12

Which peptides have been studied for erections?

Three have human studies in men, mostly small. Melanotan 2 led to erections in 17 of 20 men with erectile dysfunction in a crossover study,13 PT-141 gave erectile responses in small trials, mostly of a nasal form,14 and one kisspeptin-54 infusion increased penile tumescence in 32 men with low sexual desire.15 None of them is approved for erectile dysfunction.161718 Sildenafil (Viagra), which is used for erectile dysfunction, works by increasing blood flow to the penis during sexual stimulation.1920

Written by D2C Peptides Editorial Team.

Pending qualified review.

Updated .

Sources

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  2. Same source as 1: results.
  3. Effects of single nightly injections of growth hormone-releasing hormone (GHRH 1-29) in healthy elderly men (Vittone et al.), body composition and safety. Metabolism (PubMed abstract PMID 9005976, via NCBI E-utilities), 1997.
  4. Same source as 3: strength.
  5. Determination That GEREF (Sermorelin Acetate) Injection Products Were Not Withdrawn From Sale for Reasons of Safety or Effectiveness (discontinuation letter). U.S. Food and Drug Administration, Federal Register (GovInfo), 2013.
  6. Blackman MR et al. 2002 (PMID 12425705): carpal tunnel and arthralgia in men. JAMA, via PubMed (NCBI E-utilities), 2002.
  7. Same source as 6: diabetes and glucose intolerance.
  8. Liu H et al. 2007 (PMID 17227934): adverse events. Annals of Internal Medicine, via PubMed (NCBI E-utilities), 2007.
  9. GENOTROPIN prescribing information: How supplied (handling and Rx statement). U.S. Food and Drug Administration (Drugs@FDA label, Pfizer), 2025.
  10. Rastrelli G et al. Factors affecting spermatogenesis upon gonadotropin-replacement therapy: a meta-analytic study. Andrology 2014;2(6):794-808 (PMID 25271205), overall result. Andrology (PubMed record via NCBI E-utilities), 2014.
  11. Current landscape of fertility induction in males with congenital hypogonadotropic hypogonadism (Dwyer AA et al.; PMID 39190467). Annals of the New York Academy of Sciences, 2024.
  12. Bhasin S et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab 2018;103(5):1715-1744 (PMID 29562364). Journal of Clinical Endocrinology and Metabolism (PubMed record via NCBI E-utilities), 2018.
  13. Melanocortin receptor agonists, penile erection, and sexual motivation: human studies with Melanotan II (Wessells et al., PMID 11035391), erection excerpt. International Journal of Impotence Research, 2000.
  14. Double-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 (Diamond LE et al.), PMID 14963471. International Journal of Impotence Research (abstract via PubMed E-utilities, NLM), 2004.
  15. Effects of Kisspeptin on Sexual Brain Processing and Penile Tumescence in Men With Hypoactive Sexual Desire Disorder: A Randomized Clinical Trial (Mills et al.), abstract. JAMA Network Open (PubMed record via NCBI E-utilities), 2023.
  16. FDA Fast Facts: FDA Warns Melanotan II Maker (US Pharm. 2007;32(10):72), warning letter excerpt. U.S. Pharmacist, 2007.
  17. VYLEESI (bremelanotide injection) prescribing information: Indications and Usage. DailyMed, U.S. National Library of Medicine (label by Cosette Pharmaceuticals, revised 3/2024), 2024.
  18. DailyMed search results for kisspeptin. DailyMed, NIH/NLM, 2026.
  19. Sildenafil: MedlinePlus Drug Information (what it treats). U.S. National Library of Medicine (MedlinePlus).
  20. Same source as 19: MedlinePlus Drug Information (how it works).
  21. Hsieh TC et al. Concomitant intramuscular human chorionic gonadotropin preserves spermatogenesis in men undergoing testosterone replacement therapy. J Urol 2013;189(2):647-50 (PMID 23260550), semen results. Journal of Urology (PubMed record via NCBI E-utilities), 2013.
  22. Same source as 21: pregnancies.
  23. Pregnyl (chorionic gonadotropin) for injection, prescribing information revised 3/2023: Adverse Reactions (males). U.S. Food and Drug Administration, Drugs@FDA label (BLA 017692, Organon), 2023.
  24. Novarel (chorionic gonadotropin) for injection, US label (DailyMed, updated August 27, 2025): Contraindications. DailyMed, U.S. National Library of Medicine (Ferring Pharmaceuticals, BLA017016), 2025.
  25. MENOPUR (menotropins for injection) prescribing information, Patient Information and Instructions for Use, revised February 2014 (supplement 014). U.S. Food and Drug Administration, Drugs@FDA label (Ferring Pharmaceuticals Inc.), 2014.
  26. Direct Healthcare Professional Communication: Menopur 75 IU, interim supply of Irish packs to mitigate supply disruptions in UK (29 June 2023). Ferring Pharmaceuticals Ltd in agreement with the MHRA, published on GOV.UK, 2023.
  27. Finkel DM, Phillips JL, Snyder PJ. Stimulation of spermatogenesis by gonadotropins in men with hypogonadotropic hypogonadism. N Engl J Med 1985;313(11):651-5 (PMID 3927163). New England Journal of Medicine (PubMed record via NLM E-utilities), 1985.
  28. The Pulsatile Gonadorelin Pump Induces Earlier Spermatogenesis Than Cyclical Gonadotropin Therapy in Congenital Hypogonadotropic Hypogonadism Men (Zhang L et al.; PMID 30569789), abstract. American Journal of Men's Health, 2019.
  29. WADA Prohibited List 2026, as published in the Dutch Treaty Series (Tractatenblad 2026, nr. 25). Officiele Bekendmakingen, Government of the Netherlands (text of the World Anti-Doping Agency 2026 Prohibited List), 2026.
  30. Clinical and experimental study of the peptide bioregulator Testagen (Khavinson V.Kh., Ryzhak G.A.; article in Russian). RLS Encyclopedia (Register of Medicines of Russia), rlsnet.ru, 2021.
  31. PubMed search for 'testagen'. PubMed, National Library of Medicine, 2026.
  32. Evaluation 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 (Rosen RC et al.), PMID 14999221. International Journal of Impotence Research (abstract via PubMed E-utilities, NLM), 2004.
  33. Co-administration of low doses of intranasal PT-141, a melanocortin receptor agonist, and sildenafil to men with erectile dysfunction results in an enhanced erectile response (Diamond LE et al.), PMID 15833522. Urology (abstract via PubMed E-utilities, NLM), 2005.
  34. Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study (Safarinejad MR, Hosseini SY), PMID 18206919. Journal of Urology (abstract via PubMed E-utilities, NLM), 2008.
  35. Should Bremelanotide Be Considered for the Treatment of Sexual Arousal and Desire Disorders in Men? (Pfaus JG, Balon R), PMID 41960633. Journal of Clinical Psychopharmacology (record via Europe PMC), 2026.
  36. Same source as 13: desire excerpt.
  37. Same source as 13: nausea excerpt.
  38. Melanotan Tanning Injection: A Rare Cause of Priapism (Mallory et al., PMID 33460908). Sexual Medicine, 2021.
  39. Effects of Kisspeptin on Sexual Brain Processing and Penile Tumescence in Men With Hypoactive Sexual Desire Disorder (Mills et al.): full text. JAMA Network Open (PMC), 2023.
  40. Effect of vilon on neuroendocrine status and sexual function of old male rats. Advances in Gerontology, 2006.
  41. FDA Briefing Document, PCAC December 4, 2024, CJC-1295 evaluation (PDF page 46, human safety conclusions). U.S. Food and Drug Administration, Center for Drug Evaluation and Research, 2024.
  42. EGRIFTA WR prescribing information: 14 Clinical Studies, Study 1 baseline characteristics. U.S. Food and Drug Administration (Drugs@FDA label, BLA 022505), 2025.
  43. Pulsatile secretion of growth hormone (GH) persists during continuous stimulation by CJC-1295, a long-acting GH-releasing hormone analog (Ionescu M, Frohman LA), PubMed PMID 17018654. Journal of Clinical Endocrinology and Metabolism (abstract via NCBI PubMed E-utilities), 2006.
  44. Activation of the GH/IGF-1 axis by CJC-1295, a long-acting GHRH analog, results in serum protein profile changes in normal adult subjects (Sackmann-Sala L et al.), PubMed PMID 19386527. Growth Hormone and IGF Research (abstract via NCBI PubMed E-utilities), 2009.
  45. Peptides in urology and sexual medicine: clinical effectiveness, dosing, indications, and safety: a narrative review (Vasylieva V et al.). Sexual Medicine Reviews, 2026.
  46. FDA Briefing Document, Pharmacy Compounding Advisory Committee Meeting, December 4, 2024: CJC-1295-Related Bulk Drug Substances (FDA evaluation dated 11/15/2024). U.S. Food and Drug Administration, 2024.
  47. Effect of a new synthetic hexapeptide to selectively stimulate growth hormone release in healthy human subjects (Ilson BE et al.; PMID 2543692). Journal of Clinical Endocrinology and Metabolism (abstract via NCBI PubMed E-utilities), 1989.
  48. Growth hormone (GH)-releasing peptide stimulates GH release in normal men and acts synergistically with GH-releasing hormone (Bowers CY et al.; PMID 2108187). Journal of Clinical Endocrinology and Metabolism (abstract via NCBI PubMed E-utilities), 1990.
  49. Effects of a prolonged growth hormone (GH)-releasing peptide infusion on pulsatile GH secretion in normal men (Jaffe CA et al.; PMID 7903313). Journal of Clinical Endocrinology and Metabolism (abstract via NCBI PubMed E-utilities), 1993.
  50. Growth hormone (GH)-releasing peptide-6 requires endogenous hypothalamic GH-releasing hormone for maximal GH stimulation (Pandya N et al.; PMID 9543138). Journal of Clinical Endocrinology and Metabolism (abstract via NCBI PubMed E-utilities), 1998.
  51. Pharmacokinetic study of Growth Hormone-Releasing Peptide 6 (GHRP-6) in nine male healthy volunteers (Cabrales A et al.; PMID 23099431). European Journal of Pharmaceutical Sciences (abstract via NCBI PubMed E-utilities), 2013.
  52. The growth hormone-releasing activity of a synthetic hexapeptide in normal men and short statured children after oral administration (Bowers CY et al.; PMID 1730807). Journal of Clinical Endocrinology and Metabolism (abstract via NCBI PubMed E-utilities), 1992.
  53. Growth Hormone Secretagogue Treatment in Hypogonadal Men Raises Serum Insulin-Like Growth Factor-1 Levels (Sigalos et al.), design. Am J Mens Health (PubMed abstract PMID 28830317, via NCBI E-utilities), 2017.
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  55. Effects of a growth hormone-releasing hormone analog on endogenous GH pulsatility and insulin sensitivity in healthy men (Stanley TL et al.): design. J Clin Endocrinol Metab (PubMed abstract via NCBI E-utilities), 2011.
  56. Same source as 55: GHRH analog in healthy men (Stanley TL et al., 2011): glucose.
  57. Same source as 55: GHRH analog in healthy men (Stanley TL et al., 2011): conclusion.
  58. Same source as 6: lean body mass in men.
  59. A pro-diabetogenic mtDNA polymorphism in the mitochondrial-derived peptide, MOTS-c (Zempo et al.). Aging (Albany NY), 2021.
  60. Increased expression of the mitochondrial derived peptide, MOTS-c, in skeletal muscle of healthy aging men is associated with myofiber composition (D'Souza et al.). Aging (Albany NY), 2020.
  61. FDA Grants Accelerated Approval to First Treatment for Barth Syndrome (who is affected). U.S. Food and Drug Administration, 2025.
  62. Drug Trials Snapshots: FORZINITY (who participated). U.S. Food and Drug Administration, 2025.
  63. FORZINITY prescribing information: Clinical Trials Experience (population). DailyMed, U.S. National Library of Medicine (label by Stealth BioTherapeutics Inc., revised 9/2025), 2025.
  64. MOUNJARO (tirzepatide) injection Prescribing Information, Medication Guide and Instructions for Use, revised 08/2026 (NDA 215866/S-044, S-045). U.S. Food and Drug Administration (Drugs@FDA), 2026.
  65. Zepbound Prescribing Information, revised 08/2026: Section 6.1, Hair Loss. Eli Lilly and Company; posted by U.S. Food and Drug Administration, 2026.
  66. Same source as 65: Section 14.2 Obstructive Sleep Apnea Studies 5 and 6 (Tables 8 and 9).
  67. RYBELSUS and OZEMPIC (semaglutide) tablets, Prescribing Information and Medication Guide (NDA 213051/S-030, revised 1/2026). U.S. Food and Drug Administration (Novo Nordisk labeling), 2026.
  68. Same source as 42: EGRIFTA WR (tesamorelin) for injection, prescribing information: 1 Indications and Usage.