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PT-141 (bremelanotide) · Dose evidence · updated 8 October 2026

PT-141 dosage: what studies actually used

The short answer

PT-141 is another name for bremelanotide, the drug in Vyleesi67. The US Vyleesi label sets one dose: 1.75 mg injected under the skin as needed, at least 45 minutes before anticipated sexual activity, with no more than one dose in 24 hours and more than 8 doses a month not recommended7. It is approved only for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD), not for men or for women after menopause7. In the dose-finding trial, 0.75 mg did no better than placebo, and 1.75 mg was the dose taken into Phase 389. This page reports those doses and is not dosing advice.

Not dosing advice. This page reports doses that studies and approved labels used, with their sources. It does not recommend a dose, and we do not give mixing, injection or unit-conversion instructions. Gray-market vials often do not contain what their label says. How we report doses.

Every dose studied in people

StudyWhoPeopleDose and routeWhat happened
RECONNECT studies 301 and 302 (Kingsberg 2019), two Phase 3 randomized placebo-controlled trials Premenopausal women with HSDD 1,267 1.75 mg as needed, about 45 minutes before sexual activity; at most 1 dose per 24 hours and 12 per 4 weeks
Injection under the skin · 24 weeks		 From each woman’s starting score to her last visit (week 24 for those who finished), desire scores rose 0.30 and 0.42 points more than on placebo in the two trials, and distress about low desire fell 0.37 and 0.29 points more, but the change in satisfying sexual events did not differ significantly9. More women stopped early on the drug than on placebo (40% vs 13% and 39% vs 25%), and those who stopped were counted with their last score79. Nausea affected 40.0% versus 1.3% on placebo9. Women used a median of 10 injections over the 24 weeks7.
RECONNECT open-label extension (Simon 2019) Women who completed either Phase 3 trial without a serious adverse event 684 1.75 mg as needed
Injection under the skin · 52 weeks		 There was no placebo group, and 272 of the 684 women finished10. The most common side effects judged related to the drug were nausea in 40.4%, flushing in 20.6% and headache in 12.0%, and there were no new safety signals10. Women used a median of 12 injections over the 52 weeks7.
Phase 2b dose-finding trial (Clayton 2016), randomized and placebo-controlled Premenopausal women with HSDD, sexual arousal disorder or both 397 0.75, 1.25 or 1.75 mg as desired; at most 1 a day and 16 per 4 weeks
Injection under the skin · 12 weeks at home, after 2 doses in the clinic		 Of 397 women randomized, 327 gave data for the main analysis8. The 1.25 and 1.75 mg groups together gained 0.7 satisfying sexual events a month versus 0.2 on placebo (p = 0.0180), while 0.75 mg did no better than placebo8. Nausea affected 18% on 0.75 mg, 22% on 1.25 mg and 24% on 1.75 mg, versus 3% on placebo8.
Safarinejad 2008, randomized placebo-controlled trial (under an expression of concern) Married men aged 28 to 59 with erectile dysfunction who did not respond to sildenafil (Viagra) 342 10 mg, 45 minutes to 2 hours before sexual stimulation, for at least 16 attempts at home
Nasal spray · At least 16 doses; the abstract gives no length in weeks		 In January 2023 the journal published an expression of concern about this paper, a notice that warns readers of possible problems with it, so this page does not report the trial’s results12.
Nausea-prevention study (Vyleesi label), Phase 4, randomized and placebo-controlled Healthy women 228 One 1.75 mg dose, 30 minutes after ondansetron 8 mg or placebo by mouth
Injection under the skin · Single dose		 Taking ondansetron, an anti-nausea drug, beforehand did not reduce nausea from the dose, and the label says that this pre-treatment is not recommended7.
Blood pressure monitoring study (FDA review), open-label, then randomized withdrawal Premenopausal women 146 1.75 mg once a day
Injection under the skin · 8 days, then randomly assigned to the drug or placebo up to day 16		 Of 146 women enrolled, 127 finished the first 8 days, when daytime blood pressure was up an average of 1.9 mmHg systolic and 1.7 mmHg diastolic711. The rise did not keep growing between days 8 and 16, and it was back to baseline by the day after the drug was stopped11.
Spana 2022, study A, Phase 1 randomized placebo-controlled trial White women aged 18 to 55 with obesity (body mass index 30 to 37) 58 Three doses a day at 12:00, 16:00 and 20:00: 1.25 mg, then 1.0 mg twice on day 1; 2.5 mg, then 2.0 mg twice on later days
Injection under the skin · 15 days		 Weight fell 2.1 kg on the drug versus 0.7 kg on placebo after 16 days12. Patches of darker skin appeared in 63.3% versus 7.1% on placebo, and nausea in 30.0% versus 14.3%12. Of the 30 women on the drug, 27 finished12.
Spana 2022, study B, Phase 1 randomized crossover trial Women aged 18 to 45 with obesity (body mass index 30 to 40) 27 Placebo, 2.5 mg once a day, or 2.5 mg plus 2.0 mg a day, one regimen per period
Injection under the skin · Three 4-day periods, with 5-day breaks between them		 Only 15 of 27 women finished all three periods12. Six were withdrawn under the trial’s blood pressure rules, but only two of them had just received bremelanotide, and no one’s readings went above 155 mmHg systolic or 95 mmHg diastolic12. Weight fell 1.7 kg on two doses a day versus 0.9 kg on placebo after 4 days12.
Alcohol interaction study (Vyleesi label), randomized double-blind three-way crossover Healthy men and women, 12 of each 24 One 20 mg dose or placebo spray, 10 minutes after alcohol (0.6 g/kg) or a placebo drink
Nasal spray · Three single-dose periods		 Alcohol did not change blood levels of the drug7. Flushing was more common than with alcohol alone but similar to the drug alone, and no one stopped because of side effects7.
Diamond 2005, randomized crossover study Men with erectile dysfunction who said Viagra or Levitra worked for them 19 7.5 mg PT-141 plus sildenafil 25 mg, versus sildenafil 25 mg alone and versus placebo
Nasal spray (sildenafil as a tablet) · Three single-dose sessions, each monitored for 6 hours		 Erections during visual sexual stimulation were significantly greater with the combination than with sildenafil alone3. The authors reported the combination was safe and well tolerated, with no new side effects and none more frequent or more severe than with a single drug3.
Diamond 2006, randomized double-blind placebo-controlled crossover study Premenopausal women with female sexual arousal disorder 18 One 20 mg dose or placebo, each in a separate clinic session
Nasal spray · Two single-dose sessions		 More women reported moderate or high sexual desire after the drug than after placebo (P = 0.0114), but vaginal blood engorgement (vasocongestion) measured during erotic videos did not change significantly versus placebo6.
Rosen 2004, two studies, with a placebo crossover in patients Healthy men, and men with erectile dysfunction who reported an inadequate response to Viagra – 0.3 to 10 mg (healthy men); placebo, 4 or 6 mg in a crossover (patients)
Injection under the skin · Not stated in the abstract		 Healthy men had a statistically significant erectile response at doses above 1.0 mg, and patients had one at both 4 and 6 mg13. The authors reported it was safe and well tolerated in both studies13.
Diamond 2004, double-blind placebo-controlled studies Healthy men, and men with mild to moderate erectile dysfunction who responded to Viagra – Range not stated in the abstract
Nasal spray · Not stated in the abstract		 The erectile response was statistically significant compared with placebo at doses above 7 mg, with the first erection about 30 minutes after the dose14. No maximum tolerated dose was found, and flushing and nausea were the most common side effects14.
BMT-801 (NCT06565611), randomized Phase 2 trial Adults aged 18 to 65 with obesity, after 4 weeks on tirzepatide 2.5 mg weekly 96 1.25 mg once a day, with or without tirzepatide 2.5 mg weekly, versus tirzepatide alone or placebo
Injection under the skin · 4 weeks, after a 4-week tirzepatide lead-in		 Over the 8 weeks, weight fell 4.4% with the combination versus 1.6% in the group switched to placebo, and 40% versus 27% lost 5% of their weight with the combination versus tirzepatide alone; these results come from a company press release, and the registry record has no posted results1516.
BREAKOUT (NCT05709444), open-label Phase 2 study Adults with type 2 diabetic kidney disease 16 0.5 mg twice a day
Injection under the skin · Six months		 Eight of the 16 finished; Palatin reported skin darkening in 71% of patients without giving the number, and the registry record has no posted results1718.

The approved schedule (Vyleesi (FDA label))

Vyleesi is approved for premenopausal women with acquired, generalized HSDD: low sexual desire that causes marked distress or interpersonal difficulty and is not due to a co-existing medical or psychiatric condition, problems with the relationship, or the effects of a medication or drug substance7. Acquired means it developed in someone who previously had no problems with sexual desire, and generalized means it occurs regardless of the type of stimulation, situation or partner7. The label says it is not for women after menopause, for men, or to enhance sexual performance, and it must not be used by people with uncontrolled high blood pressure or known cardiovascular disease7. The steps below follow the label’s dosing section; that label, revised in March 2024, was the only bremelanotide label listed on DailyMed as of 8 October 202647.

WhenDose on the labelNote
Each dose1.75 mg under the skin (subcutaneously), as neededAt least 45 minutes before anticipated sexual activity; the duration of efficacy after each dose is unknown
Within 24 hoursNo more than one doseThe efficacy of consecutive doses within 24 hours has not been established, and doses close together may add to the rise in blood pressure
Each monthMore than 8 doses is not recommendedFew patients in Phase 3 took more than 8 a month; more frequent dosing raises the risk of skin darkening and lengthens the time each month when blood pressure is raised
After 8 weeksStop treatmentIf the patient does not report an improvement in her symptoms

Studies, animals and users: kept apart

Doses below are what studies used or what a label says. They are not advice, and gray-market products may not contain what their label says.

In human studies

Approved label: 1.75 mg injected under the skin as needed, at least 45 minutes before expected sexual activity; no more than one dose in 24 hours; more than 8 doses a month is not recommended; stop after 8 weeks without improvement7. Phase 3 allowed up to 12 doses per 4 weeks9, but women used it two to three times a month on average11. Phase 2b tested 0.75, 1.25 and 1.75 mg under the skin as desired8. Early studies in men used injected doses of 0.3 to 10 mg, with erectile effects above 1.0 mg13, and nasal doses, with erectile effects above 7 mg14; a study in women used one 20 mg nasal dose6. Phase 1 weight studies in women with obesity gave three injections a day for 15 days (2.5 mg, then 2.0 mg twice, after a lower first day), or 2.5 mg once a day or 2.5 mg plus 2.0 mg a day in 4-day periods12. A Phase 2 obesity trial gave 1.25 mg once a day for 4 weeks, with or without tirzepatide1516, and a study in type 2 diabetic kidney disease gave 0.5 mg twice a day for six months1718. The longest daily dosing described in the label is 16 days7.

In animal studies

Female rats: injections under the skin of 50, 100 or 200 µg/kg were given 5 minutes before mating tests; 100 and 200 µg/kg significantly increased solicitation (mating-invitation) behavior20. Reproductive toxicity: pregnant dogs received 2, 8 or 20 mg/kg under the skin on gestation days 18 to 35, with 3- to 8-fold more post-implantation loss at every dose; pregnant mice received 30, 75 or 150 mg/kg/day, with developmental delays in offspring at 30 mg/kg/day and above7.

What users report Anecdotal · not validated · not a recommendation

A dosing-protocol website (updated 20 September 2026) lists 500 µg to 1.5 mg injected under the skin once a day19.

Half-life and how it is taken

Half-life
about 2.7 hours (range 1.9–4.0 hours)7Mean terminal half-life in humans after a single subcutaneous dose of Vyleesi; blood levels peak about 1 hour after injection
Routes
  • Subcutaneous injection: the approved Vyleesi autoinjector; Phase 2 and Phase 3 human data
  • Intranasal spray: early Phase 1 and 2 studies in men and women; dropped because absorption varied
  • Intravenous: used in some early company studies
  • Gray-market vials are sold as powder for injection; nasal products were not verified

Why the label limits doses per day and per month

Each dose briefly raises blood pressure and lowers heart rate: in clinical studies, systolic pressure rose by up to 6 mmHg and diastolic pressure by up to 3 mmHg, peaking 2 to 4 hours after the dose, while heart rate fell by up to 5 beats per minute7. Both usually returned to baseline within 12 hours, and with doses 24 hours apart the label reports no additive effect for up to 16 days7. In the Phase 3 trials, 3.9% of women took at least two doses less than 12 hours apart, even though they had been told to take no more than one in 24 hours11.

Few women in the Phase 3 trials used it often: FDA’s reviewers counted 9 of 620 women in the placebo-controlled trials who used it more than seven times a month, and wrote that there is ‘very limited safety information with more than 8 doses per month’11.

Patches of darker skin, called focal hyperpigmentation, were reported in 1% of women who took up to 8 doses a month in the Phase 3 trials, including on the face, gums and breasts, and in no one on placebo7. In another study, 38% of participants developed them after 8 days of daily doses, and among those who kept taking it for 8 more days, another 14% developed new patches7. People with dark skin were more likely to develop them, and clearing after stopping was not confirmed in all patients; for the cases in the Phase 3 trials, FDA’s reviewers documented clearing in half during follow-up711.

What changed at higher doses

Blood levels rise less than in proportion to the dose between 0.3 and 10 mg, and average peak levels plateau at 7.5 mg, about 4.3 times the maximum recommended dose7. The label warns that nausea, skin darkening and larger rises in blood pressure are more likely with higher doses7.

In the dose-finding trial, nausea was the only one of the most common side effects (nausea, flushing and headache) that rose with dose, and only slightly8. Blood pressure monitoring in the same trial found systolic pressure 3.1 and 3.2 mmHg higher than on placebo in the 4 hours after two monitored doses of 1.75 mg, and 2.4 and 3.0 mmHg higher after two doses of 1.25 mg; peak rises typically lasted less than 15 minutes5.

A 20 mg nasal dose, which gives average peak blood levels 2.5 times those of a Vyleesi injection, did not prolong the QTc interval, an ECG measure of how long the heart takes to reset between beats, to any clinically relevant extent7.

Why ‘PT-141’ vials are not the approved drug

The label’s dose describes Vyleesi, the approved injection7. Vials sold online as ‘PT-141’ are a separate, unapproved product: on 24 August 2026 FDA warned five online sellers that the ‘PT-141’ they sold was an unapproved new drug, and one letter says that ‘research use only’ labels did not change that finding2122232425. Finnrick, a testing service, failed 53 of 151 ‘PT-141’ samples from March 2025 to September 2026; its standard requires at least 99.5% purity and a dose within 35% of the label26. A ‘PT-141’ product that WIRED bought at a Brooklyn bodega and had tested in 2026 did not contain the labeled active ingredient27.

Questions people ask

How much PT-141 should I take?

The only approved dose is on the Vyleesi label: 1.75 mg injected under the skin as needed, no more than once in 24 hours, with more than 8 doses a month not recommended7. That label covers only premenopausal women with acquired, generalized HSDD, not men or women after menopause7. Ask a prescriber whether it fits you.

Can you take PT-141 every day?

Not within the label, which allows no more than one dose in 24 hours and does not recommend more than 8 doses a month7. FDA’s reviewers found that daily dosing for 16 days ‘considerably increased the risk of focal hyperpigmentation’, or patches of darker skin11.

How long before sex should you take PT-141?

The label says at least 45 minutes before anticipated sexual activity, and adds that how long each dose works is unknown and the best window for taking it has not been fully characterized7. In the Phase 3 trials, women were told to take it about 45 minutes beforehand7.

What is the PT-141 dose for men?

There is none on a label, because Vyleesi is not approved for men7. Published studies in men tested injections and nasal sprays31314. One of them, a trial of a 10 mg nasal spray in 342 men, has been under an expression of concern since January 202312. In 2007 the developers delayed plans for Phase 3 trials in erectile dysfunction after FDA questioned the efficacy results and cited blood pressure increases as its greatest safety concern28. In June 2024 Palatin announced a new study in men combining bremelanotide with a Viagra-type drug; we found no results as of 8 October 2026293031.

Why is the PT-141 dose 1.75 mg?

The Phase 3 report says 1.75 mg was selected ‘based on optimal efficacy and an acceptable safety profile’ in the earlier dose-finding trial9. In that trial, the lowest dose, 0.75 mg, did no better than placebo8.

Go deeper

Sources

  1. 1Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study The Journal of Urology, Mar 2008. pubmed.ncbi.nlm.nih.gov
  2. 2Expression 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
  3. 3Co-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 Urology, Apr 2005. pubmed.ncbi.nlm.nih.gov
  4. 4DailyMed search: bremelanotide (1 label on 8 October 2026: Vyleesi, Cosette Pharmaceuticals) U.S. National Library of Medicine (DailyMed), accessed 8 Oct 2026. dailymed.nlm.nih.gov
  5. 5Usefulness of ambulatory blood pressure monitoring to assess the melanocortin receptor agonist bremelanotide Journal of Hypertension, Apr 2017. pubmed.ncbi.nlm.nih.gov
  6. 6An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist Journal of Sexual Medicine, Jul 2006. pubmed.ncbi.nlm.nih.gov
  7. 7VYLEESI (bremelanotide injection) prescribing information Cosette Pharmaceuticals via DailyMed (U.S. National Library of Medicine), 13 Nov 2025. dailymed.nlm.nih.gov
  8. 8Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial Women’s Health (London), Jun 2016. pubmed.ncbi.nlm.nih.gov
  9. 9Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials Obstetrics & Gynecology, Nov 2019. pubmed.ncbi.nlm.nih.gov
  10. 10Long-Term Safety and Efficacy of Bremelanotide for Hypoactive Sexual Desire Disorder Obstetrics & Gynecology, Nov 2019. pubmed.ncbi.nlm.nih.gov
  11. 11NDA 210557 Multi-discipline Review and Evaluation (bremelanotide) U.S. Food and Drug Administration, CDER, Jun 2019. accessdata.fda.gov
  12. 12Effect 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
  13. 13Evaluation 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
  14. 14Double-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
  15. 15Palatin Announces MC4R Agonist Bremelanotide Co-Administered with GLP-1/GIP Tirzepatide Meets Primary Endpoint in Phase 2 Obesity Study Palatin Technologies, 31 Mar 2025. palatin.com
  16. 16A Phase 2 Study Evaluating the Co-Administration of Bremelanotide With Tirzepatide for the Treatment of Obesity (NCT06565611) ClinicalTrials.gov, 6 Mar 2025. clinicaltrials.gov
  17. 17Palatin Announces Positive Phase IIb BREAKOUT Study Results in Patients with Type 2 Diabetic Nephropathy Palatin Technologies, 19 Dec 2024. palatin.com
  18. 18A Phase IIb, Multicenter, Open-Label, Prospective Study of Bremelanotide in Diabetic Kidney Disease (NCT05709444) ClinicalTrials.gov, 17 Oct 2024. clinicaltrials.gov
  19. 19PT-141 (10 mg Vial) Dosage Protocol PeptideDosages.com, 20 Sep 2026. peptidedosages.com
  20. 20Selective facilitation of sexual solicitation in the female rat by a melanocortin receptor agonist Proceedings of the National Academy of Sciences, 6 Jul 2004. pmc.ncbi.nlm.nih.gov
  21. 21Warning letter to Peak Performance Peptides (MARCS-CMS 735127) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  22. 22Warning letter to Royal Peptides LLC (MARCS-CMS 734884) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  23. 23Warning letter to NuScience Peptides LLC (MARCS-CMS 733652) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  24. 24Warning letter to Peptide Partners LLC (MARCS-CMS 735063) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  25. 25Warning letter to TXP Innovations LLC dba Tex Peptides (MARCS-CMS 735067) U.S. Food and Drug Administration, 24 Aug 2026. fda.gov
  26. 26PT-141 Safety Testing Results & Vendor Ratings Finnrick, accessed 8 Oct 2026. finnrick.com
  27. 27Those Viral Bodega Peptides Aren’t Actually Peptides WIRED, 15 Sep 2026. wired.com
  28. 28King 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
  29. 29Palatin 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
  30. 30PubMed 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
  31. 31ClinicalTrials.gov search for condition ‘erectile dysfunction’ and intervention ‘bremelanotide’ (0 studies on 8 October 2026; 0 with ‘PT-141’) ClinicalTrials.gov, accessed 8 Oct 2026. clinicaltrials.gov

Not medical advice. Talk to a licensed clinician before using any drug. Report an error.