PT-141 (Bremelanotide): How It Works for Libido, Dosage for Men & Women, Side Effects

Key takeaways

• PT-141 is bremelanotide, a synthetic cousin of the hormone that darkens skin, acting on melanocortin receptors in the brain (MC4R) and in the skin (MC1R). It is the only peptide with an FDA approval for low sexual desire: Vyleesi, approved in 2019 for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD).
• The approval rests on two 24-week trials in 1,247 premenopausal women: desire scores rose about 0.3 points more than placebo on a 1.2-to-6 scale, distress fell about 0.3 points more, and satisfying sexual events did not change. The effect is real and small, and 40% of women had nausea.
• In men, PT-141 produced erections in phase 2 trials in 2004, but FDA questioned the efficacy data and named blood pressure as its greatest safety concern in 2007, the nasal spray was dropped, and nothing for men was ever approved. Use in men today is off-label and rests on that twenty-year-old data.
• The studied dose in women is 1.75 mg under the skin at least 45 minutes before sex, at most once in 24 hours and eight times a month; men were studied at 1 to 10 mg subcutaneously and 7.5 to 20 mg intranasally. Compounded vials and sprays are usually dosed below both, and no trial has tested them.
• Bremelanotide is the active ingredient of an approved drug, so a licensed pharmacy can legally compound it on a prescription; it is not on FDA's Category 2 list. Vendors selling 'research' PT-141 were among the five warned by FDA in August 2026.

PT-141 (bremelanotide) at a glance

Also called

bremelanotide, bremelanotide acetate, Vyleesi, PT141

Class

Melanocortin receptor agonist (MC4R in the brain and MC1R in the skin are the targets that matter at therapeutic doses); a cyclic seven-amino-acid analog of alpha-melanocyte-stimulating hormone

Route

Subcutaneous injection (the approved autoinjector); compounded as an injection or a nasal spray

FDA status

FDA-approved in 2019 as Vyleesi for premenopausal women with acquired, generalized hypoactive sexual desire disorder (HSDD). Not approved for men or for postmenopausal women. Compounded bremelanotide is not an FDA-approved product.

FDA Category 2 (compounding restricted)

No

Available by prescription (US)

Yes: brand Vyleesi (premenopausal women), or compounded on prescription within the essentially-a-copy limit

Best-studied use

Hypoactive sexual desire disorder in premenopausal women (the approved indication); erectile dysfunction in men (phase 2 trials only, never approved)

Typical monthly cost (telehealth, 2026)

$60–$200 per month compounded; brand Vyleesi costs several hundred dollars per carton of four autoinjectors at list price

What PT-141 is and how it works

Bremelanotide is a cyclic peptide of seven amino acids built on alpha-melanocyte-stimulating hormone (alpha-MSH), the hormone that tells skin cells to make pigment. It is a close relative of Melanotan II, the illegal tanning injection, differing by a single chemical group at one end of the ring. Melanotan II was being tested as a sunless tanning agent in the 1990s when University of Arizona researchers noticed that the men in the studies were having erections; a 10-man placebo-controlled crossover trial then confirmed it, at the price of nausea, stretching and yawning (Wessells 1998). Palatin Technologies developed PT-141 from that observation.

Bremelanotide is not selective: it activates several melanocortin receptor subtypes, and at therapeutic doses the two that matter are MC1R and MC4R (Vyleesi label). MC4R sits on neurons across the central nervous system, including the medial preoptic area of the hypothalamus, a region involved in sexual motivation in both sexes; in hormone-primed female rats, PT-141 selectively increased the solicitation behaviors females use to initiate sex, the finding that redirected the drug toward women (Clayton 2016). MC1R sits on melanocytes, and activating it increases pigment, which is why focal skin darkening is a side effect rather than an accident.

Two things follow. First, PT-141 works upstream, in the brain, not on the genitals; it is not a PDE5 inhibitor and does not change blood flow directly, which is why men were studied as sildenafil failures rather than as sildenafil replacements. Second, the label is candid that "the mechanism by which Vyleesi improves HSDD in women is unknown"; the rat work is a hypothesis about dopamine in the preoptic area, not a demonstration in humans.

After a subcutaneous injection, bremelanotide peaks in the blood at about one hour, has a half-life of about 2.7 hours and is close to 100% bioavailable (Vyleesi label). That short half-life is why it is an as-needed drug rather than a daily one.

What the evidence actually shows

PT-141 is unusual among wellness peptides in having a full FDA review behind it, and the review documents are blunt about what the drug does and does not do.

PT-141 (bremelanotide) claims, graded by the evidence behind them

Claim	Grade	What the evidence shows	Sources
Increases sexual desire in premenopausal women with HSDD	A	Two identical 24-week placebo-controlled trials (RECONNECT; 1,247 women, mean age 39). The FSFI desire score (scale 1.2 to 6) rose 0.5 and 0.6 points on bremelanotide 1.75 mg versus 0.2 on placebo; median change 0.6 versus 0. Significant in both trials; about 0.3 points better than placebo.	Kingsberg 2019; Vyleesi label
Reduces distress about low desire	A	The co-primary endpoint, one question scored 0 to 4, fell 0.7 points versus 0.4 on placebo in both trials: significant, and again about 0.3 points.	Kingsberg 2019; Vyleesi label
Increases the number of satisfying sexual events	C	No difference from placebo in either phase 3 trial (a secondary endpoint). In the 12-week phase 2b trial (327 women), the pooled 1.25 and 1.75 mg doses added 0.7 events a month versus 0.2 on placebo.	Vyleesi label; Clayton 2016
The benefit is clinically meaningful	C	An independent re-analysis of the FDA application reproduced the small effects and added what the trial report omitted: discontinuation for side effects was about twelve times more likely on bremelanotide (number needed to harm 6), and placebo users were more likely to finish and choose the extension; in study 1, 40% on bremelanotide and 13% on placebo left early.	Spielmans 2021; Vyleesi label
Produces erections in men with erectile dysfunction	B	Phase 2 laboratory studies with rigidity monitoring: intranasal doses above 7 mg produced erections starting about 30 minutes after dosing; subcutaneous 4 and 6 mg did so in men with an inadequate response to sildenafil. No phase 3 trial followed, and FDA questioned the efficacy results in 2007.	Diamond 2004; Rosen 2004; King/Palatin 2007
Rescues men who fail sildenafil	C	Small crossover data: subcutaneous 4 to 6 mg in inadequate responders, and 7.5 mg intranasal plus 25 mg sildenafil in 19 men, which beat sildenafil alone. The one large trial (342 men, 10 mg intranasal, 33.5% versus 8.5% response) carries a 2023 expression of concern, and the same author's trial in women was retracted; we do not count it.	Rosen 2004; Diamond 2005; Safarinejad 2008
Raises sexual desire in men	D	No bremelanotide trial has measured desire in men; the only signal is a questionnaire result in 10 men given Melanotan II, a different compound.	Wessells 1998
Works for postmenopausal women	D	Excluded from the phase 3 trials; the label says not indicated. The other published female data are a 2006 crossover study of a single 20 mg nasal dose in 18 premenopausal women with arousal disorder.	Vyleesi label; Diamond 2006
A nasal spray works as well as the injection	D	Nasal doses of 7.5 to 20 mg were active in 2004 to 2006, but the nasal program was shelved after FDA named blood pressure as its greatest safety concern in 2007. Compounded sprays deliver a fraction of the studied doses and have no efficacy data.	Diamond 2004; King/Palatin 2007; Clayton 2016

Three things stand out.

First, the size of the effect. A 0.3-point difference on a 1.2-to-6 desire scale, and no change in satisfying sexual events, is what two well-run trials in more than a thousand women found. The label's own responder figures count only completers, and far fewer completed on the drug than on placebo. The effect is statistically solid and, in the words of independent reviewers, modest (Spielmans 2021).

Second, tolerability decides who benefits. Nausea in 40% and an 18% dropout rate for side effects mean that for a large minority the question of efficacy never arises. The women who do well are the ones who tolerate it: in the 52-week open-label extension, which had no placebo group, 684 women enrolled, 272 completed, and scores kept improving in those who stayed (Simon 2019).

Third, the male data are old and were never confirmed. The 2004 phase 2 papers measured erections with a rigidity monitor and showed a dose-dependent effect. The phase 3 trials that would have shown whether PT-141 helps men have sex at home were never run, because the regulator was not convinced the benefit justified the blood pressure risk (King/Palatin 2007).

What you are promised versus what is documented

Clinic pages for PT-141 make the same promises: better libido in both sexes, stronger erections, works when Viagra does not, no cardiovascular effects, and sometimes a tanning or fat-loss bonus. The evidence sorts them as follows.

• Documented in humans: a small rise in desire and a small fall in distress in premenopausal women with HSDD; erections in laboratory studies of men at 4 mg and above subcutaneously or above 7 mg intranasally; a transient rise in blood pressure after every dose.
• Plausible but unproven: usefulness in men who fail PDE5 inhibitors (the small crossover studies point that way; the large trial is compromised); any effect in postmenopausal women; any effect of a compounded spray or lozenge at the doses dispensed.
• Not supported: "no cardiovascular effects" (the label contraindicates it in cardiovascular disease); more satisfying sexual events; benefit for low desire in men; fat loss (no human trial has measured weight); tanning as a benefit (patchy hyperpigmentation is a side effect, not a tan).

PT-141 vs Vyleesi, flibanserin, PDE5 inhibitors and testosterone

For a premenopausal woman, the honest comparison is Vyleesi versus flibanserin versus no drug: nausea and injections against a nightly pill and alcohol rules, with small effects either way (Addyi label). For a postmenopausal woman, transdermal testosterone is the option with trial evidence (see the peptides for women guide). For a man with erectile dysfunction, PDE5 inhibitors are first-line by a wide margin, and PT-141 is an unapproved add-on with twenty-year-old data.

Dosage: what was studied versus what clinics prescribe

Two gaps deserve attention. For women, a compounded 1 mg injection is 40% below the only dose shown to work, and the phase 2b trial's primary analysis pooled only the 1.25 and 1.75 mg arms. For men, the doses that produced erections were 4 mg and up by injection, two to three times the female label dose, which is also where the blood pressure problem lives: a man prescribed 1 mg is taking an untested amount, and a man prescribed 4 mg is taking an amount FDA was uncomfortable with.

Timing and use

• 45 minutes before, not 15. The label's timing follows a one-hour peak in blood levels; the male studies saw first erections at about 30 minutes.
• No stacking. Two doses within 24 hours add to the blood pressure effect and were never tested for added benefit; eight doses a month is a ceiling, not a target, and daily dosing is what darkened skin in 38% of women within eight days (Vyleesi label).
• The eight-week stop rule. The label tells prescribers to discontinue if there is no improvement after eight weeks; a clinic that keeps refilling without asking is not following it.

Reconstitution example

Compounded bremelanotide usually arrives as a 10 mg lyophilized vial. Reconstituted with 2 mL of bacteriostatic water it gives 5 mg/mL (5,000 mcg/mL), so the labeled 1.75 mg dose is 0.35 mL, which reads as 35 units on a U-100 insulin syringe, and 1 mg is 0.2 mL or 20 units. Vial sizes and dilutions differ between pharmacies, so run your own numbers in the reconstitution calculator and trust the pharmacy label over the calculator if they disagree; technique is in how to inject peptides.

Side effects and who should not use it

The adverse-event profile comes from 627 women on bremelanotide and 620 on placebo in the phase 3 trials, plus the open-label extension (Vyleesi label).

Nausea starts within about an hour and lasts about two hours; 21% of women had it after the first dose and about 3% after later ones, 13% needed an anti-nausea drug, and 8% quit because of it. Ondansetron taken beforehand, tested in 228 women, did not prevent it. Overall, 18% stopped for side effects versus 2% on placebo.

Blood pressure and heart rate. Every dose raises systolic pressure by up to about 6 mmHg and diastolic by about 3 mmHg, peaking two to four hours after injection, with a drop in heart rate of up to 5 beats a minute; both return to baseline within about 12 hours. Small numbers in healthy premenopausal women; they matter because of who else takes the drug: middle-aged men with erectile dysfunction, in whom hypertension and vascular disease are common, which is why FDA balked at the male program.

Focal hyperpigmentation. Darkening of patches of skin, including the face, gums and breasts, occurred in 1% of women using up to eight doses a month and in none on placebo; with daily dosing, 38% developed it within eight days and a further 14% in the next eight. It was more common in darker skin and had not resolved in every woman who stopped.

Drug interactions. Bremelanotide slows stomach emptying and can reduce the absorption of oral drugs taken around the same time. The label singles out oral naltrexone, whose exposure may fall enough to cause treatment failure in someone using it for alcohol or opioid dependence (avoid the combination), and indomethacin, whose onset may be delayed; antibiotics and other oral drugs that need a threshold concentration should not be taken alongside it. Alcohol does not change bremelanotide's blood levels.

Do not use PT-141, or use it only with a specialist's sign-off, if you have:

• uncontrolled high blood pressure or known cardiovascular disease (contraindicated), or a high cardiovascular risk (not recommended);
• severe kidney or liver disease (exposure roughly doubles, with more nausea and vomiting);
• a pregnancy or a plan for one: the label requires effective contraception and discontinuation if pregnancy is suspected, and cites fetal harm in pregnant dogs at 16 times the human exposure; the seven trial pregnancies are too few to say anything;
• breastfeeding (no data on human milk);
• oral naltrexone for addiction;
• a history of melanoma or many atypical moles: not on the label, but melanocortin agonists stimulate melanocytes; ask a dermatologist first.

Legal status in the United States

PT-141 has the cleanest legal position of any peptide sold for libido, and it still gets misdescribed.

• It is an approved drug. Bremelanotide was approved as Vyleesi in June 2019 for premenopausal women with HSDD; it is now marketed by Cosette Pharmaceuticals under a label dated March 2024, and a clinician may prescribe it off-label, including to men, as with any approved drug.
• It can be legally compounded. Under section 503A a pharmacy may compound a substance that is a component of an FDA-approved drug, and bremelanotide acetate is the active ingredient of Vyleesi. It has never been on the Category 2 safety-risk list, so none of the 2026 removals, votes or pending rulemaking affect it; see the 2026 legal tracker. One nuance: federal law bars pharmacies from routinely compounding what is essentially a copy of a commercially available drug, so a compounded product identical to Vyleesi needs a prescriber-documented clinical reason, which is partly why compounded PT-141 usually comes in different strengths or as a nasal spray. Online directories that say PT-141 cannot be compounded at all are wrong on the federal basis; the pharmacy's state license and the prescriber's documentation are what to ask about.
• Research vials are unapproved drugs. On August 24, 2026, FDA sent warning letters to five online vendors selling peptides with "research use only" labels, PT-141 among the products named, treating dosing guides, reconstitution calculators and bundled bacteriostatic water as evidence that the vials were intended as drugs (ArentFox Schiff 2026). Buying one is not a crime; selling one is, and the product has no verified content.
• State rules still apply. A prescription is valid only from a clinician licensed in your state.

Cost and how to get it prescribed

As of October 2026, compounded bremelanotide runs about $60 to $200 a month depending on the number of doses, and programs that bundle the clinician visit land in the $150 to $350 range typical of wellness peptides; brand Vyleesi lists at several hundred dollars per carton of four autoinjectors. The cost guide has the full table.

What a legitimate prescription looks like:

1. A real evaluation for HSDD. Low desire that is distressing and not explained by depression, a relationship problem, a medical condition or a medication (antidepressants are the common culprit).
2. A blood pressure check before the first prescription and periodically, as the label requires.
3. Contraception counseling for women who could become pregnant.
4. A named, state-licensed pharmacy on the prescription, with a labeled concentration and beyond-use date.
5. A plan to stop: follow-up at eight weeks and discontinuation if nothing has changed.

Red flags: a shopping cart instead of a consultation, PT-141 for men marketed as proven, a nasal spray sold without mention of the studied dose, a bundle with peptides no pharmacy may legally compound, or a promise of results in 15 minutes.

PT-141 for women versus men

Women. The approved population is premenopausal women with acquired, generalized HSDD, the only group with trial data at the labeled dose. Postmenopausal women were excluded, the label says the drug is not indicated for them, and no published study has tested 1.75 mg after menopause. For a postmenopausal woman with distressing low desire, the option with randomized evidence is transdermal testosterone dosed to premenopausal female levels, which adds about one satisfying sexual event a month over placebo in the pooled trials; flibanserin's indication was widened in December 2025 to women under 65 regardless of menopausal status (Addyi label). Both are covered in the peptides for women guide; pregnancy is a hard stop, with contraception required and discontinuation if pregnancy is suspected.

Men. The story is a stalled development program. Intranasal PT-141 produced erections at 7.5 to 20 mg in 2004, subcutaneous 4 to 6 mg did the same in men who responded poorly to sildenafil, and a 19-man crossover study found that low-dose nasal PT-141 improved the response to sildenafil (Diamond 2005). In August 2007, Palatin and its partner King Pharmaceuticals announced that FDA had questioned the efficacy results and clinical benefit in men, had cited blood pressure increases as its greatest safety concern, and had suggested at most a second-line role for men who fail PDE5 inhibitors; the phase 3 plans were shelved (King/Palatin 2007), the nasal formulation was abandoned, and the later female trials carried 24-hour blood pressure monitoring because of those nasal studies (Clayton 2016). In June 2024 Palatin began an open-label phase 2 study of about 50 PDE5-inhibitor non-responders, testing bremelanotide co-formulated with a PDE5 inhibitor in a single injection (Urology Times 2024); as of October 2026 we have found no published results. A man prescribed PT-141 today is relying on the female safety data and the 2004 efficacy data, usually at a dose below the one that worked.

Bottom line

PT-141 is the one libido peptide that is a real drug: approved, labeled, legally compoundable, and studied in more than a thousand women. What it reliably does is raise desire scores a little and lower distress a little in premenopausal women with HSDD, at the cost of nausea in four out of ten and a short rise in blood pressure after every dose. What it has not been shown to do is increase satisfying sexual encounters, help postmenopausal women, or treat erectile dysfunction outside a laboratory in 2004.

A reasonable use is a premenopausal woman with a proper HSDD diagnosis, normal blood pressure and reliable contraception, prescribed by a clinician who will stop it at eight weeks if it does nothing. A less reasonable use is a man buying a nasal spray on the promise that it works where Viagra failed; the trial quoted for that claim is under an expression of concern, and the regulator that read all the data was not convinced.

Frequently asked questions

+−What is PT-141 spray used for?

PT-141 nasal spray is a compounded form of bremelanotide, sold for low sexual desire in women and erectile dysfunction in men. The nasal route is where the drug started: intranasal doses of 7.5 to 20 mg produced erections in men and raised reported desire in women in studies published between 2004 and 2006. The manufacturer then dropped the spray after FDA questioned the efficacy data and named blood pressure increases as its greatest safety concern in 2007, and the drug was approved only as a 1.75 mg injection. Compounded sprays usually deliver far smaller doses than the ones studied, and no trial has tested them.

+−Can PT-141 be used to treat erectile dysfunction?

It has never been approved for it. In phase 2 studies from 2004, subcutaneous PT-141 at 4 and 6 mg and intranasal PT-141 above 7 mg produced measurable erections, including in men who responded poorly to sildenafil. FDA was not persuaded that the benefit outweighed the blood pressure risk, the phase 3 program for men was shelved in 2007, and a new phase 2 study of bremelanotide co-formulated with a PDE5 inhibitor for men who do not respond to PDE5 inhibitors only began in 2024. Prescribing PT-141 to a man today is off-label and rests on that twenty-year-old data.

+−Does PT-141 have to be injected?

The only FDA-approved form, Vyleesi, is a single-dose autoinjector given under the skin of the abdomen or thigh. Compounding pharmacies also dispense bremelanotide as a nasal spray, and a few offer troches, but the spray doses that were actually studied were 7.5 to 20 mg, and the absorption of compounded sprays and lozenges has not been measured. Swallowed, a peptide this size is digested like food, so a true pill form does not exist.

+−What is the most effective peptide for increasing female arousal?

Bremelanotide is the only peptide with an FDA approval for low sexual desire in women, so by default it is the most proven. The honest size of the effect is small: in two 24-week trials in premenopausal women, desire scores rose about 0.3 points more than placebo on a scale that runs from 1.2 to 6, distress fell about 0.3 points more, and the number of satisfying sexual events did not change. It is approved for desire, not arousal, and it was not studied in postmenopausal women, for whom transdermal testosterone has better evidence.

+−How long does PT-141 last?

Bremelanotide has a half-life of about 2.7 hours and reaches peak blood levels about an hour after a subcutaneous dose, which is why the label says to inject it at least 45 minutes before anticipated sexual activity. In the male studies, erections began roughly 30 minutes after a nasal dose and were monitored for about six hours. The label says the duration of the effect on desire is unknown. Blood pressure rises for a few hours and returns to baseline within about 12 hours, and nausea typically lasts about two hours.

+−What are the side effects of PT-141?

In the approval trials, 40% of women had nausea (versus 1% on placebo), 20% flushing, 13% injection-site reactions, 11% headache and 5% vomiting; 18% stopped the drug because of side effects, compared with 2% on placebo. Each dose raises systolic blood pressure by about 6 mmHg and slows the heart by up to 5 beats a minute for a few hours. Focal darkening of the skin, gums or breasts occurred in 1% of women using up to eight doses a month and in 38% of women dosed daily for eight days, and it did not always fade after stopping.

+−Is PT-141 FDA approved?

Yes, as Vyleesi, approved in June 2019 for premenopausal women with acquired, generalized hypoactive sexual desire disorder. It is not approved for men, for postmenopausal women, or to enhance sexual performance. Compounded PT-141 from a pharmacy is not an FDA-approved product, and vials sold online as research chemicals are unapproved drugs; FDA named PT-141 in its August 2026 warning letters to five online vendors.

+−What is the PT-141 dosage for women and for men?

The only labeled dose is for women: 1.75 mg under the skin as needed, at least 45 minutes before sex, no more than one dose in 24 hours and no more than eight doses a month, stopping after eight weeks if there is no improvement. Men have no labeled dose. The male studies used 0.3 to 10 mg subcutaneously (effective above 1 mg in healthy men; 4 and 6 mg in men with erectile dysfunction) and 7.5 to 20 mg intranasally. Compounded prescriptions for men are often 1 to 2 mg, which is below the doses that produced erections in the trials, and no study has tested them.

+−How long does PT-141 stay in your system?

With a half-life of about 2.7 hours (range 1.9 to 4.0), bremelanotide is essentially gone from the blood within about 14 hours of a dose; roughly 65% of it leaves in the urine. People with moderate kidney impairment have about 1.5 times the exposure and those with severe impairment about twice, which is why the label advises caution in those groups. It is not a controlled substance and is not part of standard drug screens.

+−Can you take PT-141 with Viagra?

They act on different systems, the brain for PT-141 and penile blood flow for sildenafil, and the Vyleesi label lists no interaction with PDE5 inhibitors. A 2005 crossover study gave 19 men 7.5 mg of intranasal PT-141 with 25 mg of sildenafil and found a larger erectile response than sildenafil alone without new side effects. The caution is blood pressure: PT-141 raises it transiently while sildenafil lowers it, nobody has studied the combination at compounded doses, and men with cardiovascular disease should not use PT-141 at all.

Sources

1. LabelCosette Pharmaceuticals. VYLEESI (bremelanotide injection) prescribing information, revised March 2024. DailyMed. (2024)
2. StudyKingsberg SA et al. Bremelanotide for the treatment of hypoactive sexual desire disorder: two randomized phase 3 trials. Obstet Gynecol 2019;134:899-908. (2019)
3. StudySimon JA et al. Long-term safety and efficacy of bremelanotide for hypoactive sexual desire disorder. Obstet Gynecol 2019;134:909-17. (2019)
4. StudyClayton AH et al. Bremelanotide for female sexual dysfunctions in premenopausal women: a randomized, placebo-controlled dose-finding trial. Womens Health (Lond) 2016;12:325-37. (2016)
5. ReviewSpielmans GI. Re-analyzing phase III bremelanotide trials for 'hypoactive sexual desire disorder' in women. J Sex Res 2021;58:1085-105. (2021)
6. StudyDiamond LE et al. 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. Int J Impot Res 2004;16:51-9. (2004)
7. StudyRosen RC et al. 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. Int J Impot Res 2004;16:135-42. (2004)
8. StudyDiamond LE et al. 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. Urology 2005;65:755-9. (2005)
9. StudyDiamond LE et al. An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist. J Sex Med 2006;3:628-38. (2006)
10. StudyWessells H et al. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover study. J Urol 1998;160:389-93. (1998)
11. StudySafarinejad MR, Hosseini SY. Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study. J Urol 2008;179:1066-71. Expression of concern issued by the journal in January 2023; cited here only to explain why we do not rely on it. (2008)
12. NewsKing Pharmaceuticals and Palatin Technologies. King Pharmaceuticals, Inc. and Palatin Technologies delay immediate plans for phase 3 clinical program with bremelanotide for erectile dysfunction (FDA questioned the efficacy results and cited blood pressure increases as its greatest safety concern). Press release via BioSpace, August 30, 2007. (2007)
13. NewsClarke H. Phase 2 study launches of bremelanotide plus a PDE5 inhibitor for erectile dysfunction. Urology Times, June 20, 2024. (2024)
14. LabelSprout Pharmaceuticals. ADDYI (flibanserin) tablets prescribing information; indication revised December 2025 to women under 65 with acquired, generalized HSDD. DailyMed. (2025)
15. NewsArentFox Schiff. RUO-ined: five peptide vendors learn that research use only is not a legal strategy (FDA warning letters of August 24, 2026, covering PT-141 among other peptides). September 18, 2026. (2026)