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All peptides
Melanocortin receptor agonist

PT-141 (Bremelanotide)

Also known as: Bremelanotide, Vyleesi, PT141

Tier 1 — Human RCTReviewed 2026-05-04

FDA-approved as Vyleesi for premenopausal HSDD. Off-label use for male erectile function and on-demand libido is widespread but supported by far thinner evidence.

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Overview

PT-141 (bremelanotide) is a cyclic 7-amino-acid synthetic peptide developed from alpha-MSH analogs. Unlike sildenafil-class drugs, which act peripherally on vascular tone, PT-141 acts centrally on melanocortin receptors involved in sexual desire and arousal. The FDA approved bremelanotide as Vyleesi in June 2019 for hypoactive sexual desire disorder (HSDD) in premenopausal women, on the strength of two Phase 3 RCTs (RECONNECT 301 and 302). Off-label use in men for erectile function and in postmenopausal women is widespread but supported by older Phase 2 data only.

Mechanism

Non-selective melanocortin receptor agonist with primary activity at MC3R and MC4R. Acts centrally on neural circuits in the medial preoptic area and paraventricular nucleus that regulate sexual desire and arousal — a fundamentally different mechanism from PDE-5 inhibitors, which act peripherally on vascular tone in erectile tissue. The central mechanism is also why PT-141 affects desire (not just performance), and why it produces nausea and flushing in a substantial minority of users.

Evidence by indication

We classify each indication separately. The same peptide can be Tier 1 for one use and Tier 4 for another. Tiers reflect the published literature, not the strength of community framing.

Hypoactive Sexual Desire Disorder (HSDD) in premenopausal women

Tier 1high confidence

RECONNECT 301 and 302 (Kingsberg et al.; n>1,200 across both trials) demonstrated significant improvements vs placebo on the FSFI-Desire and FSDS-DAO distress measures. FDA-approved as Vyleesi in 2019 for this exact indication.

Kingsberg SA et al. 2019Palatin Technologies / AMAG Pharmaceuticals et al. 2019

Erectile dysfunction (off-label, male)

Tier 3high confidence

Older Phase 2 trials (Diamond 2004, Rosen 2004) reported modest erectogenic effects, but the development program for ED was halted in 2008 due to safety concerns (sustained blood pressure increases, particularly with the intranasal formulation). No Phase 3 program in male ED exists. Widespread off-label use in self-experimenter and 'sexual performance' clinics rests on the older Phase 2 data.

Diamond LE et al. 2004Safarinejad MR et al. 2008

Sexual function in postmenopausal women

Tier 3high confidence

Vyleesi's FDA label is explicitly limited to premenopausal women. Postmenopausal use was not separately approved; available data in postmenopausal populations is small and inconclusive.

Palatin Technologies / AMAG Pharmaceuticals et al. 2019

On-demand libido / 'date night' use in healthy adults without HSDD

Tier 4high confidence

No published trials assess PT-141 in healthy users without sexual dysfunction. Self-reported community use is heavy; primary literature for this specific indication does not exist.

No primary citations are anchored to this indication — the tier reflects the absence of usable literature, not a missing reference.

Studied dose ranges

The ranges below come from published trial protocols where available, and from documented self-experimenter consensus where the literature does not include human dose-finding work. The notes flag which is which.

1,750–1,750 mcgas needed, ≤1 dose per 24 hours and ≤8 doses per month · subcutaneous (autoinjector)

FDA-approved Vyleesi dose is 1.75 mg subcutaneously via autoinjector at least 45 minutes before anticipated sexual activity. Compounded research-vendor PT-141 is sometimes dosed at 1–2 mg by self-injection; off-label male use varies. Older intranasal formulations were discontinued during development.

Contraindications

  • Uncontrolled hypertension or established cardiovascular disease (transient BP elevations of ~6 mmHg systolic / 3 mmHg diastolic post-dose; case-by-case judgement)
  • History of cardiovascular events (MI, stroke) — Vyleesi label cautions
  • Pregnancy (use a reliable contraceptive; women becoming pregnant should discontinue)
  • Concomitant oral naltrexone (PT-141 may reduce naltrexone exposure)
  • Hypersensitivity to bremelanotide or excipients
  • Caution: history of melanoma or numerous atypical nevi (theoretical concern from melanocortin receptor activity at MC1R)

Reported side effects

  • Nausea (~40% of Vyleesi users; most common reason for discontinuation; usually peaks 1–4 hours post-dose)
  • Flushing (~20%)
  • Injection site reactions (~13%)
  • Headache
  • Vomiting
  • Transient blood pressure increases (typically mild; resolve within ~12 hours)
  • Focal hyperpigmentation (face, gums, breasts) with repeated dosing — under-recognized; reversible on discontinuation in most cases
  • Darkening of nevi or new pigmented lesions (rare; flagged on the label)

Reconstitution & storage

FDA-approved Vyleesi is a pre-filled, single-use autoinjector that does not require user reconstitution. Compounded or research-vendor PT-141 is sold as lyophilized powder, typically 10 mg vials. Example: a 10 mg vial in 2 mL bacteriostatic water = 5 mg/mL; a 1.75 mg dose ≈ 0.35 mL = 35 units on a U-100 syringe. Verify with the calculator.

Storage. Vyleesi autoinjector: room temperature 20–25 °C, do not freeze. Compounded lyophilized: refrigerate 2–8 °C. Reconstituted: refrigerate 2–8 °C; use within ~30 days.

Open the peptide calculator → to compute exact draw volumes for your specific vial and BAC water choice.

Editorial note

DRAFT — pending Wayne's review. PT-141 is a clean Tier 1 case for HSDD in premenopausal women — that's the FDA-approved indication, full stop. The off-label male ED and 'date night' use is the wedge: development was halted on cardiovascular safety, and the literature for those uses is materially weaker. The hyperpigmentation side effect is consistently under-discussed in consumer write-ups; surface it.

Citations

  1. [1]
    Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials
    Kingsberg SA, Clayton AH, Portman D, et al. · Obstetrics & Gynecology · 2019 · PMID 31135708
    Tier 1 evidence for the HSDD indication in premenopausal women (RECONNECT 301/302).
    View source
  2. [2]
    An effect on the subjective sexual response in premenopausal women with sexual arousal disorder by bremelanotide (PT-141), a melanocortin receptor agonist
    Diamond LE, Earle DC, Heiman JR, Rosen RC, Perelman MA, Harning R · Journal of Sexual Medicine · 2004 · PMID 15311206
    Older Phase 2 sexual-function evidence used to anchor Tier 3 for off-label uses.
    View source
  3. [3]
    Salvage of sildenafil failures with bremelanotide: a randomized, double-blind, placebo controlled study
    Safarinejad MR, Hosseini SY · Journal of Urology · 2008 · PMID 18173768
    Phase 2 male ED evidence. Development was later halted on safety; tier remains 3 for ED.
    View source
  4. [4]
    Vyleesi (bremelanotide injection) Prescribing Information
    Palatin Technologies / AMAG Pharmaceuticals · FDA-approved label · 2019
    Approved indication, dose, contraindications, and label warnings (BP, hyperpigmentation).
    View source