Sexual healthBremelanotideVyleesi

PT-141

FDA-approved melanocortin receptor agonist · on-demand (SC + intranasal)

PT-141, generic name bremelanotide, is a small ring-shaped peptide that switches on melanocortin receptors — cell switches the body uses both for skin pigmentation and for sexual-arousal pathways in the brain. Unlike Viagra-type drugs, which work on genital blood flow, it acts mainly in the central nervous system to raise sexual desire itself, which is why it is classed as a treatment for low desire rather than mechanical erectile failure. It is FDA-approved as Vyleesi (2019) for one narrow use: acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, injected under the skin on an as-needed basis about 45 minutes before sex. The honest framing is that it works but modestly — in the large Phase 3 RECONNECT trials, desire scores rose and distress scores fell by small, statistically real amounts, and only a minority of women felt a meaningful benefit. Roughly 4 in 10 users get nauseous, it briefly raises blood pressure (so it is off-limits in uncontrolled hypertension or heart disease), and it can cause patchy darkening of skin or gums. Its widespread internet reputation as a male libido peptide rests on early, inconclusive studies in men that never reached approval.

The short version

PT-141 is a small, ring-shaped synthetic peptide that switches on melanocortin receptors — cell "switches" the body normally uses for two unrelated jobs: regulating skin and hair pigmentation, and modulating sexual-arousal pathways in the brain. Because it activates these switches, it can both darken skin (a side effect) and increase sexual desire (its intended effect).

It is sold as Vyleesi, an FDA-approved (2019) self-injected medicine for premenopausal women with HSDD — hypoactive sexual desire disorder, meaning persistently low sexual desire that causes the person real distress, not just a mismatch with a partner. A single dose is injected under the skin of the belly or thigh about 45 minutes before anticipated sex, on an as-needed basis — not daily. Unlike Viagra-type drugs, which work on blood flow in the genitals, PT-141 works mainly in the brain to raise desire itself.

The honest catch is that it works but modestly. In the large Phase 3 trials, desire scores went up and distress scores went down by small-but-statistically-real amounts, and only a minority of women felt a meaningful benefit. Roughly 4 in 10 users get nauseous. It also briefly raises blood pressure — so it is off-limits for people with uncontrolled high blood pressure or heart disease — and it can cause patchy darkening of skin or gums. Its widespread reputation as a "male libido peptide" is based on early, inconclusive studies in men that were never carried to approval.

Molecular identity

Specs

Molecular weight: 1025.2 g/mol (free base)
Molecular formula: C50H68N14O10
Monoisotopic mass: 1024.5243 Da
CAS / UNII: 189691-06-3 · 6Y24O4F92S
Half-life: ~2.7 h terminal (range 1.9–4.0 h)

Sequence: Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH (7 AA, Asp–Lys lactam bridge)PubChem CID 9941379
Structure / class: Cyclic α-MSH analog; deamidated metabolite of melanotan II (free-acid C-terminus)PubChem CID 9941379
Molecular target: Melanocortin receptor agonist (MC1R > MC4R > MC3R > MC5R > MC2R)FDA Vyleesi label
Brand / approval: Vyleesi (bremelanotide) — FDA-approved 2019; 1.75 mg SC on-demand for HSDD in premenopausal womenFDA Vyleesi label
Regulatory status: FDA-approved for HSDD (premenopausal women) only; male/intranasal use is off-labelFDA Vyleesi label
Anti-doping status: Not named on the WADA 2026 Prohibited List (permitted by inference — melanocortin agonist, not S2)WADA 2026

Plain English

Mechanism

PT-141 is a non-selective melanocortin receptor agonist — "agonist" means a molecule that turns a receptor on, and the melanocortin receptors are a family of cell switches (subtypes MC1R through MC5R). Per the FDA label its potency runs MC1R > MC4R > MC3R > MC5R > MC2R, and at therapeutic doses the MC1R and MC4R effects are the ones that matter.

MC4R is the central, brain-side receptor believed to mediate the pro-sexual effect: it is found in nervous-system regions that govern sexual motivation, so activating it is thought to increase desire directly. This is a centrally mediated action — it acts on the brain rather than on genital blood vessels, which distinguishes it from PDE5 inhibitors such as sildenafil (Viagra). The label is candid that the precise mechanism by which it improves HSDD is not fully established. MC1R is the peripheral, skin-side receptor that drives melanocyte pigmentation — the basis for the hyperpigmentation side effect and for the drug's origin in the tanning peptide melanotan II.

The honesty point is the human-versus-animal split. The approved human evidence is for central desire enhancement in women. The erectile and male pro-sexual claims rest on animal models plus early-phase human male studies (intranasal and subcutaneous), not on a pivotal approval — PT-141 began as the deamidated active metabolite of melanotan II, whose tanning trial subjects unexpectedly reported arousal.

Sources:DailyMed (Vyleesi)PMID 14963471

Why people reach for it

Potential benefits

PT-141 is the melanocortin people reach for when low desire — not blood flow — is the problem. Here's what draws them to it, framed against what the approved evidence actually shows.

Works on desire itself, not just plumbing — Its defining appeal. PT-141 activates MC4R in the brain to raise sexual desire centrally — a different target from Viagra-type drugs, which work on genital blood flow — so it's reached for when the issue is wanting, not mechanical function.
An on-demand option, taken before the occasion — It's used situationally — roughly 45 minutes before anticipated activity — rather than as a daily pill, which suits people who want something to reach for around a specific occasion.
The melanocortin with an actual FDA approval — As Vyleesi (2019) it is approved for acquired, generalized HSDD in premenopausal women — the only melanocortin with a regulatory approval specifically for sexual function, and the cleaner, better-characterized choice versus the unapproved Melanotan 2.
A pairing partner for the vascular side — Because it covers the central-desire half of arousal, people pair it with a PDE5 inhibitor that handles the peripheral-vascular half — genuinely complementary targets (with a real blood-pressure caution worth reading).
The honest framing — real but modest — In the Phase 3 RECONNECT trials the gains in desire and distress were statistically real but modest, and only a minority of women reached a meaningful response; roughly 4 in 10 users get nausea, and the widely-cited male use is off-label and unproven.

Sources:DailyMed (Vyleesi)PMID 31599840 DOI 10.2217/whe-2016-0018 PMID 14963471

What people reach for PT-141 for, drawn from what the research reports and how it's used — the approved benefit is modest and limited to HSDD in premenopausal women; this is not a claim that it cures erectile dysfunction or low desire.

Implied timing

Best time to dose

Implied best time

Situational (pre-activity)

PT-141 is taken on-demand about 45 minutes before anticipated activity — not on a daily clock.

Its whole use pattern is occasion-based: a single dose ahead of a specific occasion, then nothing until the next one. The approved Vyleesi instruction is ~45 minutes before anticipated sexual activity.
The ~2.7-hour half-life (FDA label) means the window of activity covers the immediate hours after dosing, which is why the pre-activity timing — rather than a fixed time of day — is what matters.
On-demand spacing is also the safer pattern: daily dosing is explicitly linked to higher rates of focal hyperpigmentation in the label, so the situational timing isn't just about effect, it limits a real side effect.
Frequency is capped (≤1 dose per 24 h, ≤8 per month), and nausea is eased by dosing on a light stomach — practical refinements within the pre-activity window, not a daily schedule.

No study sets an ideal time of day for PT-141, because it isn't a daily-clock drug — it's reasoned from how it's used and its pharmacokinetics. Where most peptides cluster in a midday-to-evening window, PT-141 is the situational exception: taken about 45 minutes before activity, whenever that falls.

Sources:DailyMed (Vyleesi)

How to run it

Dosing & protocol

PT-141 is used on-demand, not daily — taken roughly 45 minutes before activity. The FDA-approved route is subcutaneous (the Vyleesi autoinjector). Intranasal is the common community alternative, especially in the research-peptide context. Both routes are covered below. The only trial-validated regimen is 1.75 mg SC in premenopausal women with HSDD; male use and intranasal dosing are off-label community convention.

FDA-approved only for premenopausal women with HSDD (SC, 1.75 mg on-demand). Male use and intranasal use are off-label. Every number here is a usage pattern or approved label figure — not a validated dosing recommendation for healthy-person or male use.

Tiered dose ranges

Both routes share similar mcg magnitudes; route and form drive the practical differences.

Standard SC (label-aligned):: 1.75 mg (1,750 mcg) subcutaneously, injected ~45 minutes before anticipated sexual activity. This is the Vyleesi approved dose — the only regimen validated in Phase 3 trials.
Intranasal (community convention):: 500–2,000 mcg intranasally is the community range cited in male off-label use. Early PT-141 male trials used intranasal; that program was discontinued partly over blood-pressure concerns with the nasal form. Use at the lower end if trying intranasal for the first time.
Titration start (community, either route):: Some users begin at 500–1,000 mcg on first use to gauge nausea tolerance before stepping to the full dose. Not label-specified.
Maximum frequency:: ≤1 dose per 24 hours; ≤8 doses per month (Vyleesi label). Daily dosing significantly raises the risk of focal hyperpigmentation (skin/gum darkening) — on-demand spacing matters.

Administration — subcutaneous + intranasal

SC is the FDA-approved route (Vyleesi autoinjector). Intranasal is the community alternative. Use the route matching your form; both are taken ~45 minutes before activity.

SC — injection site:: Abdomen (staying a couple of inches clear of the navel) or the outer thigh. The Vyleesi autoinjector uses the same sites. Rotate between doses to avoid repeated-site irritation or lipohypertrophy.
SC — measuring the dose from a vial:: From a reconstituted 10 mg vial (10 mg + 2 mL bacteriostatic water = 5,000 mcg/mL): 1,750 mcg = 35 IU on a U-100 insulin syringe. The on-page calculator adjusts for any vial size. Draw slowly, no air bubbles.
SC — timing:: Inject approximately 45 minutes before anticipated sexual activity. The half-life is ~2.7 hours (FDA label), so the window of activity covers the immediate hours post-dose. On-demand only — not a daily or scheduled regimen.
Intranasal — technique:: Reconstituted solution is administered as a nasal spray or drops. With a nasal atomizer: prime the device, tilt the head slightly forward, one spray per nostril (splitting the dose across both). With drops: tilt head back slightly, instill half the dose per nostril, sniff gently inward. Avoid blowing the nose for 10 minutes after dosing.
Intranasal — why the route matters (and its limits):: The nose-to-brain pathway can deliver peptides toward the CNS by the olfactory nerve route, which is part of why early PT-141 work used intranasal delivery. However, the intranasal program was halted partly due to blood-pressure concerns — transient BP elevation is a real liability on either route, and the SC form is the one with the managed safety profile.
Nausea management (both routes):: ~40% of users experience nausea. Dosing on a light stomach (not fully empty, not fully full) reduces severity. Avoiding alcohol around dosing also helps. If nausea is severe with the first dose, titrating up from a lower amount on the second attempt is the community approach.

Use pattern

PT-141 is situational — taken before a specific occasion — not cycled or pulsed like most peptides.

On-demand, not daily:: This is the approved pattern and the safer one. Daily dosing is explicitly linked to higher rates of focal hyperpigmentation in the label; use it only when the occasion calls for it.
Maximum frequency cap:: ≤1 dose per 24 hours, ≤8 per month (Vyleesi label). These limits are meaningful: hyperpigmentation risk tracks cumulative dosing frequency, and BP elevation (a label safety flag) resets within ~12 hours of each dose.
Off-label male use:: Male use is not approved and rests only on early-phase data. Reported community doses in men are generally similar to the female label (1.75 mg SC or 1–2 mg intranasal), on-demand. Flag it as unproven when discussing with a prescriber.
8-week reassessment (label guidance):: The Vyleesi label advises discontinuing after 8 weeks if no symptom improvement. For off-label users, applying this same check-in logic is reasonable.

Reconstitution at a glance

Mixing math only — the calculator does this live. Quick reference for a standard 10 mg vial:

Mixing:: 10 mg vial + 2 mL bacteriostatic water = 5,000 mcg per mL. On a U-100 (100-unit, 1 mL) insulin syringe: 500 mcg = 10 IU · 1,000 mcg = 20 IU · 1,750 mcg = 35 IU.
Why 2 mL for this dose:: The standard 1,750 mcg dose lands at 35 IU on a 100-unit syringe — a readable, manageable increment that avoids microscopic measurements. The calculator can adjust for a 5 mL dilution if a more spread-out scale is preferred.

Sources:DailyMed (Vyleesi)PMID 31599840 PMID 14963471

Substrate the signal needs

Nutritional cofactor precision

PT-141 acts centrally — it turns on the brain's MC4R melanocortin receptor, which feeds into the dopaminergic sexual-motivation circuitry. The useful cofactors either supply the substrate that dopaminergic arousal pathway runs on, support the enzymes that build it, or mitigate PT-141's two real tolerability liabilities: transient blood-pressure rise and nausea.

Reasoned from PT-141's central MC4R/dopaminergic mechanism plus its FDA-label safety flags — not a PT-141 cofactor study. The key insight: vascular arousal supplements (arginine, citrulline, nitric oxide boosters) target the peripheral blood-flow axis PT-141 does NOT act on — pairing them expecting mechanism synergy is a category mismatch.

Amplify the central pathway — L-tyrosine (the on-axis substrate)

PT-141 works by turning on MC4R in the brain, which drives dopamine-mediated sexual motivation. Dopamine is built from L-tyrosine. That makes tyrosine the one supplement that sits directly on PT-141's axis.

L-tyrosine — 500–1,000 mg, 60 min before dosing:: The enzymatic path is clear textbook biochemistry: L-tyrosine → L-DOPA → dopamine. Adequate circulating tyrosine keeps the dopaminergic arousal circuitry well-supplied with its building block. Take on a light stomach, ~1 hour before the PT-141 dose for best absorption timing. This is the cofactor that matches PT-141's actual mechanism — not the vascular side.
The honest vascular mismatch note:: L-arginine, L-citrulline, and nitric-oxide supplements raise genital blood flow by the NO → cGMP → smooth-muscle-relaxation pathway — the same axis PDE5 inhibitors (Viagra) work on. PT-141 does NOT work on that axis; it works centrally. Pairing these with PT-141 supports the broader arousal system but is not feeding PT-141's mechanism. If you are stacking PT-141 with a PDE5 inhibitor, the PDE5 inhibitor handles the vascular side (see stack cards below) — adding arginine/citrulline on top of that is redundant at best and may amplify blood-pressure effects.

Supply the synthesis enzymes — B6, copper, vitamin C

Three cofactors that the dopamine synthesis pathway actually depends on enzymatically.

Vitamin B6 (P5P form) — 25–50 mg/day:: Pyridoxal-5-phosphate is the active cofactor for DOPA decarboxylase — the enzyme that converts L-DOPA into dopamine. Without adequate B6, the tyrosine → dopamine conversion is rate-limited at that enzymatic step. Take in the morning with food.
Copper bisglycinate — 1–2 mg/day:: Copper is the cofactor for dopamine β-hydroxylase — relevant if you are running zinc (below), since zinc at supplemental doses competes with copper absorption. The balance keeps the downstream catecholamine pathway intact rather than inadvertently pulling copper low.
Vitamin C — 500–1,000 mg/day:: Ascorbate is required by dopamine β-hydroxylase as a reducing cofactor (electron donor), maintaining enzyme activity. Routine supplementation at this range supports the full dopamine synthesis chain alongside B6 and copper.

Mitigate — blood-pressure rise + nausea

PT-141's two real label liabilities: transient BP elevation (~+6 mmHg systolic, peaks 2–4 h post-dose) and nausea (~40%). These cofactors address both without adding more pressure.

Do NOT combine with other pressors:: This is a hard rule, not a soft guideline: stimulants that raise blood pressure (high-dose caffeine, certain decongestants, sympathomimetics) stack additively on PT-141's transient BP rise. PT-141 is already contraindicated in uncontrolled hypertension and cardiovascular disease. Keeping the dosing window stimulant-light is the most important BP-mitigation step.
Magnesium glycinate — 200–400 mg the evening before or morning of dosing:: Magnesium supports vascular tone and mild vasodilation (opposes the pressor effect modestly) and also helps with nausea. Glycinate form is gentler on the gut than oxide. Evening-before timing buffers both the BP and GI sides without adding morning complexity.
Light stomach + hydration for nausea:: The label and community experience converge: dosing on a very empty stomach worsens nausea; dosing immediately after a heavy meal also worsens it. A light snack (crackers, small meal) 30–60 min before is the community sweet spot. Good hydration (16–20 oz of water around dosing) further reduces GI distress. These are the highest-yield nausea mitigations — more reliable than antiemetic supplements.
Ginger extract — 250–500 mg, 30 min before dosing (optional):: Ginger (standardized to 5% gingerols) has antiemetic evidence in chemotherapy and motion sickness contexts and is broadly used as a first-dose nausea buffer in the community. Not PT-141-specific, but it is mechanism-plausible (5-HT3 antagonism) and has a favorable safety profile.

Combinations + timing

Stacking notes + timing windows

PT-141 covers the central-desire half of sexual arousal (brain → MC4R → dopaminergic motivation). The complementary pairings add the peripheral-vascular half (PDE5 inhibitor) — that is genuinely complementary, not the same lever twice. The Melanotan-2 comparison is included as a warning, not a recommendation.

Combinations reasoned from complementary mechanisms — not regimens studied head-to-head with PT-141. The PDE5 interaction carries a real cardiovascular caution (pressor + vasodilator) that is not optional reading. Doses are community convention; 'commonly combined for' describes where users reach, not a proven indication.

PT-141 + PDE5 Inhibitor (sildenafil / tadalafil)

The most mechanistically defensible PT-141 pairing: central desire (PT-141) + peripheral vascular capacity (PDE5 inhibitor). Two halves of arousal, genuinely different levers.

Why it works:: PT-141 activates MC4R in the brain to drive dopaminergic sexual motivation — the desire side of arousal. PDE5 inhibitors (sildenafil / tadalafil) block phosphodiesterase-5 in smooth muscle, raising cGMP and allowing genital blood vessels to dilate — the physical capacity side. The mechanisms do not overlap: one is central-nervous-system, one is peripheral-vascular. For users with both low desire and mechanical-response difficulty, this is a genuinely complementary combination.
The BP interaction — this is a real medical flag:: PT-141 transiently raises blood pressure (~+6 mmHg systolic, peaks 2–4 h post-dose). PDE5 inhibitors are vasodilators that lower blood pressure. Combining a pressor with a vasodilator creates a hemodynamic interaction — the effects partly offset, but the net cardiovascular load and unpredictability are real, especially in anyone with underlying hypertension or cardiovascular disease, for whom PT-141 is already contraindicated. This combination should be discussed with a clinician before use, not approached as a casual recreational stack. It is mechanistically logical and commonly used, but the BP interaction is not a minor footnote.
The protocol:: PT-141 1,750 mcg SC or 500–2,000 mcg intranasal, ~45 minutes before activity. Sildenafil 25–50 mg orally ~60 minutes before (or tadalafil 5–10 mg taken earlier in the day for the longer-acting form). Do not double up on blood-pressure-raising compounds around this window.
Outcome:: The combination users reach for when desire and physical response both need support — most discussed in male off-label use. Women with HSDD and concomitant arousal difficulties are the population where this logic most clearly applies, though neither combination has been studied in a controlled trial.

Melanotan-2 — comparison + warning, not a recommendation

Melanotan-2 (MT-2) hits the same MC pathway as PT-141. Understanding why they are not stacked explains something important about both molecules.

Why they overlap (not complement):: Melanotan-2 is a closely related α-MSH analog that also agonizes MC1R and MC4R — the same receptors PT-141 hits. PT-141 is in fact the deamidated major metabolite of MT-2 (the C-terminal amide is removed). Running both together does not add a new lever — it piles more agonist onto the same receptors, amplifying melanocortin side effects (especially MC1R-driven hyperpigmentation and mole changes) without adding a complementary mechanism.
The safety comparison:: PT-141 has a genuine FDA approval (Vyleesi, 2019), Phase 3 trial safety data (52 weeks, n in the thousands), and a managed adverse-event profile. Melanotan-2 is an unapproved compound with more concerning pigmentation outcomes (naevi changes, widespread tanning that is difficult to reverse) and no equivalent regulatory safety review. If the goal is melanocortin-mediated sexual motivation, PT-141 is the better-characterized option by a significant margin.
The verdict:: Do not stack PT-141 with Melanotan-2. They are not complementary — they are the same pathway with one being better-evidenced than the other. If you are reaching for MT-2 for the sexual effect, PT-141 does what MT-2 does there with a much cleaner safety record.

Reconstitution math

Reconstitution calculator

Calculated for a 1 mL U-100 insulin syringe (100 units/mL).

Peptide per vial

BAC water added

Desired dose

Units per dose

Draw to this mark on a U-100 syringe

Volume per dose: 0.35 mL
Doses per vial: 5
Concentration: 5 mg/mL

One vial lasts

Daily: 5 days
Every other day: 11 days
5×/week: 8 days

Large draw (35 units). Double-check the vial size and dose — a mcg/mg mix-up produces values like this.

Research use only. Not for human consumption. Outputs are reference values based on research literature — verify all measurements independently.

From the studies

Side effects from research

Nausea is the dominant tolerability problem — roughly 40% of users across the program, most often with the first dose, and the single most common reason people stop. After nausea, the most frequent effects are flushing (~20%), injection-site reactions (~13%), and headache (~11%), with vomiting less common.

Two safety signals shape who should use it. First, each dose transiently raises blood pressure (about +6 mmHg systolic) and lowers heart rate, peaking 2–4 hours after injection and resolving within 12 hours — the basis for the contraindication in uncontrolled hypertension and known cardiovascular disease. Second, focal hyperpigmentation: darkening of the skin, face, or gums occurred in about 1% of users at up to eight doses a month, is more likely with darker skin and with daily dosing, and did not always fully resolve after stopping.

The honesty framing is the gap between reputation and approved evidence. The 52-week open-label extension found no new safety signals, so in supervised, label-aligned use it is a reasonably characterized drug — but the benefit is modest, the indication is narrow, and the male and recreational uses that drive its online popularity are unproven and outside the approval.

Sources:DailyMed (Vyleesi)PMID 31599847

As reported in literature

Research dosing ranges

These are the doses tested in the published trials, shown separately so the trial evidence is never mistaken for a recommended regimen. Bremelanotide's pivotal evidence is human and randomized — the Phase 3 RECONNECT program in premenopausal women with HSDD. The male data are early-phase only. All were given subcutaneously (or intranasally, in the discontinued male program) under medical supervision.

Dose	Route	Model	Outcome	Sources:
1.75 mg on-demand (24 wk)	SC	Human RCT (RECONNECT Phase 3, premenopausal HSDD, n≈1,247)	Statistically significant improvement vs placebo in desire (FSFI) and distress (FSDS) scores; effect sizes modest, minority reached meaningful response	PMID 31599840
1.75 mg on-demand (up to 52 wk)	SC	Human open-label extension (RECONNECT completers)	Sustained improvement, no new safety signals; related AEs nausea 40.4%, flushing 20.6%, headache 12.0%	PMID 31599847
0.75 / 1.25 / 1.75 mg (12 wk)	SC	Human Phase 2b dose-finding (premenopausal women, n≈327)	Established the 1.75 mg dose; pooled 1.25/1.75 mg increased satisfying sexual events vs placebo	DOI 10.2217/whe-2016-0018
Single/early doses	IN / SC	Human Phase 1/2 (men, healthy + mild–moderate ED)	Erectile responses (RigiScan) vs placebo — early-phase only; program later halted; NOT approved in men	PMID 14963471

Quick answers

Frequently asked

Is PT-141 FDA-approved?

Yes — as Vyleesi (2019), but only for acquired, generalized hypoactive sexual desire disorder (HSDD) in premenopausal women, dosed on-demand. It is not approved for men, postmenopausal women, or general libido enhancement.

How is it different from Viagra?

Viagra (a PDE5 inhibitor) works on genital blood flow to enable an erection; PT-141 works centrally in the brain to increase sexual desire itself. They target different problems — desire versus mechanical function — which is why PT-141 is classed as an HSDD treatment.

How well does it actually work?

In the Phase 3 RECONNECT trials the improvements in desire and distress were statistically significant but modest, and only a minority of women reached a meaningful response. It is a real effect, not a dramatic one.

What is the most common side effect?

Nausea, in roughly 40% of users — usually worst with the first dose. After that the most common effects are flushing, injection-site reactions, and headache.

Can it darken my skin?

Yes. It can cause patchy darkening of the skin, face, or gums (about 1% at up to eight doses a month), more likely with darker skin and with daily dosing, and it may not fully reverse after stopping. This is why on-demand rather than daily dosing is advised.

Does it work for men or erectile dysfunction?

Early male studies (intranasal and subcutaneous) showed erectile responses, but the male development program never reached approval, partly over blood-pressure concerns with the nasal form. Male use is off-label and unproven — the only approved use is in premenopausal women with HSDD.

Is PT-141 banned in sport?

It is not named on the 2026 WADA Prohibited List. As a melanocortin receptor agonist it does not fall within the listed categories, so the best-supported conclusion is that it is currently permitted — but this is an inference from category exclusions, not a confirmed entry, and athletes should verify current status via GlobalDRO for their sport and date.

Why is L-tyrosine recommended as a cofactor rather than L-arginine?

Because PT-141 acts centrally on the MC4R melanocortin receptor in the brain, driving dopaminergic sexual motivation. Dopamine is synthesized from L-tyrosine — that is the substrate on PT-141's actual axis. L-arginine raises nitric oxide and genital blood flow, which is the peripheral vascular axis PDE5 inhibitors target — not the mechanism PT-141 uses. The two axes are parallel, not the same lever.

Can I combine PT-141 with Viagra or Cialis?

The mechanisms are genuinely complementary (central desire + peripheral vascular), but the combination carries a real cardiovascular interaction: PT-141 transiently raises blood pressure, while PDE5 inhibitors lower it. The net hemodynamics are unpredictable and the interaction is a medical flag — particularly for anyone with hypertension or heart disease, for whom PT-141 is already contraindicated. Discuss with a clinician before combining them.

Primary sources

References

PubChem CID 9941379PubChem CID 9941379 (Bremelanotide)
DailyMed (Vyleesi)Vyleesi (bremelanotide) FDA Prescribing Information
PMID 31599840Kingsberg et al., Obstet Gynecol 2019 (RECONNECT, two Phase 3 trials)
PMID 31599847Simon et al., Obstet Gynecol 2019 (long-term safety/efficacy)
PMID 31277966Althof et al., J Sex Med 2019 (Phase 2b responder analyses)
DOI 10.2217/whe-2016-0018Clayton et al., Womens Health (Lond) 2016 (Phase 2b dose-finding)
PMID 14963471Diamond et al., Int J Impot Res 2004 (intranasal PT-141 in men)
WADA 2026WADA 2026 Prohibited List (bremelanotide not named — permitted by inference)

Research use only · Not medical advice · Updated 2026-06-01