HormonesEvidence ReviewAug 2026

Best Peptides for Men in 2026

This page reports what named studies measured when these compounds were tested. Each row below is one study with its population, endpoint, result and PubMed identifier, so any line can be checked against the record it came from. Designs run from randomised human trials to animal and cell-culture work, and populations from men only to mixed-sex groups, each named in its own column.

412

Patients randomised in the tesamorelin trial (PMID 18057338)

1.38

Odds ratio for prostate cancer, IGF-I highest versus lowest quintile (PMID 18838726)

2.1 kg

Lean body mass change on growth hormone, 220 recipients (PMID 17227934)

Background on the complaint itself. The Massachusetts Male Aging Study surveyed a community-based random sample of men aged 40 to 70 near Boston from 1987 to 1989. Combined prevalence of minimal, moderate and complete impotence was 52 percent, and complete impotence tripled from 5 to 15 percent across that range (PMID 8254833).

What the Studies Measured

One row per study, so a compound tested twice appears twice. Read the population column first: the result belongs to the people who were enrolled.

Compound	Population (n)	What was measured	Result	Design	PMID
Melanotan-II	10 men with erectile dysfunction of no known organic cause	Erection presence, duration and rigidity on RigiScan over 6 hours	Clinically apparent erections in 8 of 10. Tip rigidity above 80 percent lasted 38.0 minutes versus 3.0 on placebo, p = 0.0045	Double-blind placebo-controlled crossover	9679884
Melanotan-II	10 men with erectile dysfunction and organic risk factors	RigiScan erections and self-reported desire over 6 hours	Erections reported after 12 of 19 injections versus 1 of 21 placebo doses. Tip rigidity above 80 percent lasted 45.3 minutes versus 1.9, P = 0.047. Severe nausea after 4 injections	Double-blind placebo-controlled crossover	11018622
PT-141 (bremelanotide), subcutaneous	Healthy men, then men with an inadequate response to Viagra	RigiScan erectile response, with visual sexual stimulation in patients	Statistically significant erectile response at the higher amounts given to healthy men, and at both amounts given in the patient crossover	Dose-ranging study plus placebo-controlled crossover	14999221
Bremelanotide, intranasal	342 married men aged 28 to 59 who did not respond to sildenafil, 172 versus 170	Positive clinical result on the International Index of Erectile Function	Positive clinical results in 51 patients (33.5 percent) versus 13 (8.5 percent), p = 0.03. More drug-related adverse effects, p = 0.01. Expression of Concern, J Urol 2023, recorded on the PubMed entry	Randomised double-blind placebo-controlled	18206919
Kisspeptin-54	37 randomised, 32 completed. Men with hypoactive sexual desire disorder, mean age 37.9	Whole-brain fMRI activity during sexual video (primary); tumescence (secondary)	Brain activity modulated versus placebo, Cohen d 0.81 (95 percent CI 0.41 to 1.21), P = .003. Tumescence up to 56 percent above placebo, mean difference 0.28 units, P = .02	Double-blind crossover placebo-controlled randomised trial	36735255
Degarelix versus leuprolide	610 men with adenocarcinoma of the prostate, median age 72	Testosterone at or below 0.5 ng/mL at every monthly measurement, day 28 to day 364	Reached by 97.2, 98.3 and 96.4 percent of the three arms. At day 3, by 96.1 and 95.5 percent of the degarelix groups, none on leuprolide	Randomised open-label phase III, 12 months	19035858
Chitomur (bladder peptide bioregulator)	Men aged 62 to 83 with benign prostatic hyperplasia. The abstract states no sample size	Urodynamic parameters, urinary symptoms, prostate volume, quality of life	Significant improvement reported in main urination parameters and quality of life, holding a month past treatment. The Russian-language abstract gives direction only, no effect size	Blind randomised placebo-controlled	24640697
Prostatilen AC versus Prostatilen	98 men aged 25 to 45 with chronic abacterial prostatitis, 49 per arm	Semen analysis before and after 10 days of therapy	Total motile spermatozoa rose 14.3 percent versus 4.1 percent on the comparator. Fast progressive motility p = 0.0004, normal forms p = 0.0118	Randomised multicentre open-label phase III	36318852
RC-3940-II (gastrin-releasing peptide antagonist)	Wistar rats with testosterone-induced benign prostatic hyperplasia, plus BPH-1 and WPMY-1 cell lines	Prostate weight after 6 weeks; cell proliferation and prostatic cell volume	Prostate shrinkage of 15.9 percent at the lower of two daily amounts and 18.4 percent at the higher, P less than 0.05 for both	Rat in vivo plus cell culture. No human participants	23359692
Tesamorelin	412 patients with HIV and an accumulation of abdominal fat, 86 percent of them men	Percent change in visceral adipose tissue on CT (primary); triglycerides, IGF-I	Visceral adipose tissue fell 15.2 percent while placebo rose 5.0 percent. Triglycerides fell 50 mg/dL versus a 9 mg/dL rise. IGF-I rose 81.0 percent versus a 5.0 percent fall, P less than 0.001	Randomised placebo-controlled, 26 weeks	18057338
Ipamorelin	117 enrolled and 114 analysed, adults after bowel resection	Time from first dose to tolerance of a standardised solid meal	Median 25.3 hours versus 32.6 on placebo, p = 0.15. Treatment-emergent adverse events in 87.5 percent versus 94.8 percent	Multicentre double-blind placebo-controlled phase 2	25331030
MK-677 (oral ghrelin mimetic, not a peptide)	65 healthy adults aged 60 to 81	Fat-free mass and visceral fat at 1 year (primary); strength, function, glucose	Fat-free mass rose 1.1 kg while placebo fell 0.5 kg, P less than 0.001. No significant difference in visceral or total fat. Fasting glucose rose 0.3 mmol/L, P = 0.015. The gain did not result in changes in strength or function	2-year double-blind randomised modified crossover	18981485
Growth hormone	220 recipients across 18 study populations, mean age 69, community-dwelling	Body composition, lipids, bone density, adverse events	Lean body mass rose 2.1 kg (95 percent CI 1.3 to 2.9) and fat mass fell 2.1 kg, P less than 0.001, weight unchanged. Higher rates of soft tissue edema, arthralgia, carpal tunnel syndrome	Systematic review of randomised controlled trials	17227934
Growth hormone	303 recipients across 27 study samples, mean age 27, physically fit	Lean body mass, strength, exercise capacity, exercise lactate	Lean body mass rose 2.1 kg (95 percent CI 1.3 to 2.9). Strength and exercise capacity did not seem to improve. Exercise lactate was significantly higher in 2 of the 3 studies measuring it	Systematic review of randomised controlled trials	18347346
IGF-I, measured in blood rather than given	3,700 men later diagnosed with prostate cancer and 5,200 controls, mean age 61.5 at blood draw, diagnosis on average 5 years later	Serum IGF-I against subsequent prostate cancer risk	Odds ratio 1.38 for highest versus lowest quintile (95 percent CI 1.19 to 1.60), P less than 0.001 for trend	Individual-participant analysis of 12 prospective studies. Observational	18838726

Each PMID links to the full record. See also how peptides are injected.

What the Trials Gave

Each amount is printed with the study that used it, its route and its supervision.

Wessells et al., J Urol 1998 (PMID 9679884) and Urology 2000 (PMID 11018622), 10 men per study under RigiScan monitoring, gave:

Melanotan-II 0.025 mg/kg by subcutaneous injection

Disclaimer: what those crossover studies gave under monitoring. Not a recommendation.

Safarinejad and Hosseini, J Urol 2008 (PMID 18206919), 342 sildenafil non-responders, in a trial carrying a 2023 Expression of Concern, gave:

Bremelanotide 10 mg intranasal spray, 45 minutes to 2 hours before sexual stimulation

Disclaimer: reproduced to describe what that flagged trial did. Not a recommendation.

Mills et al., JAMA Network Open 2023 (PMID 36735255), men attending an academic research centre, gave:

Kisspeptin-54 by intravenous infusion, 1 nmol/kg/h for 75 minutes

Disclaimer: a supervised infusion inside a trial, not a self-administered regimen.

Falutz et al., N Engl J Med 2007 (PMID 18057338), 412 patients with HIV and abdominal fat accumulation, gave:

Tesamorelin 2 mg daily by subcutaneous injection

Disclaimer: that amount belongs to that trial and that patient group. The same study recorded an 81.0 percent rise in IGF-I.

Erection and Desire

Melanotan-II was tested under RigiScan at the University of Arizona in men whose erectile dysfunction had no known organic cause (PMID 9679884), then in men with organic risk factors (PMID 11018622), 10 men per study. PT-141, later named bremelanotide, went into a subcutaneous study covering healthy men and Viagra non-responders (PMID 14999221), then into a 342-man randomised trial whose PubMed entry now carries a 2023 Expression of Concern (PMID 18206919).

Kisspeptin-54 was infused in an academic research centre in men with hypoactive sexual desire disorder, where the primary outcome was brain activity on fMRI and tumescence was secondary (PMID 36735255). Compound pages: PT-141, Melanotan-II, kisspeptin.

The Prostate Studies

Prostate disease is diagnosed and managed with a doctor, and nothing here substitutes for that. The 610-patient degarelix trial reaches its endpoint by suppressing testosterone in men with prostate adenocarcinoma (PMID 19035858), which removes testosterone rather than raising it.

The benign prostatic hyperplasia trial and the chronic abacterial prostatitis trial both come from a Russian-language research tradition, and both enrolled men already carrying a diagnosis (PMID 24640697, PMID 36318852). In the Prostatilen AC trial the comparator was the same preparation without added zinc rather than placebo, and the endpoint was semen quality. RC-3940-II was tested in testosterone-induced prostatic hyperplasia in Wistar rats and in cultured BPH-1 and WPMY-1 cells (PMID 23359692).

Growth Hormone Axis

The tesamorelin trial reported a 15.2 percent fall in visceral adipose tissue and, in the same 412 patients over the same 26 weeks, an 81.0 percent rise in IGF-I (PMID 18057338). Set that beside the pooled analysis of 12 prospective studies, where higher serum IGF-I tracked with higher subsequent prostate cancer risk (PMID 18838726). That analysis is observational: it links a blood marker to risk, not a drug to a disease.

Ipamorelin has a randomised human trial with a different endpoint entirely, postoperative ileus, where median time to a tolerated meal was 25.3 hours against 32.6 on placebo, p = 0.15 (PMID 25331030). In the MK-677 trial and the growth hormone review, lean mass rose while strength and function were measured separately and moved differently (PMID 18981485, PMID 18347346). More in the HGH peptides guide, the testosterone guide and the TRT guide.

Search Provenance

Each line records one query, one index and one date, and says only what that query returned. A different synonym or MeSH entry term returns a different set, and counts drift as PubMed indexes records.

BPC-157[TIAB] OR "BPC 157"[TIAB] in PubMed on 9 August 2026 returned 214 records. The same terms AND ("clinical trial"[PT] OR "randomized controlled trial"[PT]) returned 0.
(prostatilen OR Vitaprost OR Chitomur) AND ("randomized controlled trial"[PT] OR "clinical trial"[PT]) in PubMed on 9 August 2026 returned 21 records, including PMID 24640697 and PMID 36318852.
(melanotan-II OR bremelanotide OR "PT-141") AND ("erectile dysfunction"[MeSH Terms]) AND ("randomized controlled trial"[PT]) in PubMed on 9 August 2026 returned 5 records, including PMID 11018622 and PMID 14999221.
("ipamorelin" OR "CJC-1295") AND ("clinical trial"[PT] OR "randomized controlled trial"[PT]) in PubMed on 9 August 2026 returned 4 records, including PMID 25331030.
sermorelin OR "GHRH(1-29)NH2" in PubMed on 9 August 2026 returned 391 records. The entry term is paired with the name because PubMed indexes some records under the entry term alone, so the forms return different sets.

Queries ran through the NCBI E-utilities esearch endpoint. Related: BPC-157 and SARMs versus peptides.

Blood and Vial Checks

Blood first, because testosterone and IGF-I assays differ between laboratories: peptide blood tests in Vietnam. Then the vial, because a trial result assumes a known compound at a known purity: how to verify a COA and the COA library. Other levers sit in the natural testosterone guide.

Questions

Are any of these compounds approved for men, and where?+

Bremelanotide holds a United States approval, marketed as Vyleesi, and the indication written into it is premenopausal women with acquired, generalized hypoactive sexual desire disorder (PMID 31429064). That is a regulatory fact about one jurisdiction and one label; approval elsewhere is decided by each national regulator. Tesamorelin, degarelix and leuprolide were given inside the trials described here, where the protocol set who received them, in what amount and under what monitoring (PMID 18057338, PMID 19035858).

Why do the erection trials use RigiScan rather than asking the men?+

RigiScan records rigidity continuously, so a study can report a duration such as minutes above 80 percent tip rigidity instead of a recollection. The Melanotan-II crossovers used it across a 6-hour window (PMID 9679884, PMID 11018622). The intranasal bremelanotide trial instead used the self-administered International Index of Erectile Function, over at least 16 attempts (PMID 18206919). Those endpoint families are not interchangeable, so their numbers do not line up.

What does an Expression of Concern attached to a trial mean for its numbers?+

It is a notice a journal publishes when questions raised about an article are not yet settled into a correction or a retraction. The Journal of Urology published one in 2023 on the intranasal bremelanotide trial, recorded on the PubMed entry (PMID 18206919). The article has not been withdrawn, so the figures should be read as contested rather than settled, and quoted with the notice attached.

Why does a result in men with HIV-associated fat accumulation not read across to an ordinary midsection?+

Because the enrolled population is part of the result. Everyone randomised in the tesamorelin trial had HIV and an accumulation of abdominal fat during antiretroviral therapy, the metabolic situation the trial was designed around (PMID 18057338). Applying its visceral fat figure to a man without that condition is an extrapolation, not a finding. The same caution applies to the prostate cancer, prostatitis and post-surgical results.

Why do the growth hormone rows count study populations rather than people?+

Because a systematic review pools separate trials, so it carries separate denominators: how many study populations were combined, and how many people actually received growth hormone. Behind those denominators sits a third figure, the treatment exposure: 107 person-years in the review of healthy elderly participants, and 13.3 person-years in the review of physically fit young participants (PMID 17227934, PMID 18347346). The pooled estimate is calculated across the studies, while the safety picture rests on the smaller exposed group, so quoting one denominator without the other overstates the human exposure behind it.