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PT-141

Last reviewed: April 18, 2026 by The Peptide Catalog Team

An FDA-approved peptide for sexual function and libido enhancement. PT-141 (Bremelanotide) is a melanocortin receptor agonist FDA-approved for hypoactive sexual desire disorder (HSDD) in women. Unlike PDE5 inhibitors, it works centrally in the brain to increase sexual desire rather than just blood flow. Originally derived from Melanotan II, it activates MC3R and MC4R receptors involved in sexual arousal and behavior.

CategorySexual Health & Hormone Peptides
Classmelanocortin agonist
GoalSexual Health
Overview

Core Benefits

Key Advantages
Sexual response support
FDA-approved (Vyleesi) for HSDD in premenopausal women.
Centrally-acting libido aid
Works in the brain via melanocortin receptors — not blood flow.
Works for both sexes
Effective for low libido in men and women in research.
On-demand dosing
Used 45 minutes before activity — no daily commitment.
Differs from PDE5 inhibitors
Targets desire — not physical arousal mechanism.
Injectable or nasal
Sub-Q injection or nasal spray — derived from MT-II.

These are educational summaries of commonly discussed effects in wellness/regenerative contexts, not guarantees.

PT-141 Results Timeline

Progression
1
30-45 min
Physical Changes
Possible flushing, warmth, mild nausea
Performance & Recovery
Effects begin as peptide reaches brain receptors
Other Benefits
Onset of increased sexual desire
2
1-4 hours
Physical Changes
Flushing may persist, nausea typically fades
Performance & Recovery
Peak effects — enhanced libido and arousal
Other Benefits
Improved sexual response and satisfaction
3
4-12 hours
Physical Changes
Effects gradually diminish
Performance & Recovery
Residual benefits may persist
Other Benefits
Return to baseline over several hours
4
Usage Note
Physical Changes
Some report improved skin flush, heightened sensitivity
Performance & Recovery
On-demand use, max 8 doses/month recommended
Other Benefits
FDA-approved for HSDD; works centrally, not peripherally

Timeline is illustrative and non-guaranteed. Outcomes vary and are commonly discussed alongside training, nutrition, sleep, and cycling practices.

Read the full PT-141 results timeline →

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Evidence at a glance

Two parallel grades per outcome — clinical RCT depth and real-world community adoption. See the Research Overview below for citations and detail.

OutcomeClinical EvidenceCommunity Evidence
Female HSDD (premenopausal)StrongModerate
Long-term safety in womenStrongModerate
Erectile function (off-label)ModerateModerate
How It WorksMelanocortin Agonist — MC3R/MC4R Selective (Sexual Function)

Receptor → Central Arousal Pathway → Sexual Desire → Outcomes

1
Target

MC3R/MC4R (Central Melanocortin Receptors)

PT-141 (Bremelanotide) selectively activates MC3R and MC4R receptors in the brain — the same receptors responsible for Melanotan-2's libido effects, but without significant MC1R activation (minimal tanning effect).

2
Cellular Signal

Central MC3R/MC4R → Dopaminergic Sexual Arousal Pathway

Melanocortin receptor activation in the hypothalamus triggers dopamine release in areas involved in sexual arousal and desire. Unlike PDE5 inhibitors (Viagra), which work on blood flow only, PT-141 works on desire and arousal centrally.

3
Systemic Effect

Central Sexual Arousal → Desire + Physical Response

Increased sexual desire and arousal through central brain mechanisms. Works in both men and women. FDA-approved for hypoactive sexual desire disorder (HSDD) in women as Vyleesi. Different mechanism than PDE5 inhibitors — addresses desire rather than just physical function.

4
What You Notice

Increased Desire (45 min onset) + Possible Nausea/Flushing

Increased sexual desire and arousal typically within 45 minutes. Common side effects: nausea (40%+), flushing, headache. These side effects are from melanocortin receptor activation and typically diminish with experience. Effects last several hours.

What Makes This Peptide Different

PT-141 is the only FDA-approved peptide for sexual desire. Derived from Melanotan-2 research, it isolates the MC3R/MC4R sexual function effects while minimizing tanning. Unlike Viagra (blood flow), PT-141 works on brain-based desire and arousal — a fundamentally different mechanism that works in both sexes.

Research overview

Outcome-by-outcome look at what the evidence actually supports for PT-141, including human vs. animal study counts and our editorial take on each.

Hypoactive sexual desire disorder (women)

Clinical:StrongCommunity:Moderate

Kingsberg 2019 (RECONNECT, n=1267 across two Phase 3 trials) randomized premenopausal women with acquired generalized HSDD to bremelanotide 1.75 mg SC PRN vs placebo for 24 weeks and showed significant improvements in desire and reduction in distress. FDA-approved 2019 (Vyleesi) — the second drug ever approved for female HSDD.

3 human studies · 6 animal studies

Key findings & citations
  • RECONNECT: significant improvement in FSFI desire domain and FSDS-DAO item 13 vs placebo.
  • Effect on satisfying sexual events was small (~0.5 events/month).
  • Nausea ~40% — primary reason for discontinuation.
  • Long-term 52-week extension confirmed safety profile (Simon 2019).

Our take

Approved drug with real but modest effect. Nausea is the primary reason most patients won't continue past a few doses.

Erectile function (off-label)

Clinical:ModerateCommunity:Moderate

PT-141 was originally developed for ED — Phase 2 work in the early 2000s showed pro-erectile effects, but Palatin pivoted to female HSDD due to BP elevation in male studies. Off-label use in men persists in community practice without a male-indication-specific Phase 3 program.

2 human studies · 6 animal studies

Key findings & citations
  • Early Phase 2 pro-erectile effects in men.
  • Development pivoted to female HSDD due to systolic BP elevation in men.
  • No FDA approval for male ED — off-label use only.

Our take

Works in men, but the BP signal is the reason it's not approved for ED. Use with caution in hypertensive users.

What PT-141 doesn't do

Claims that current evidence does not support. Worth knowing before you set expectations.

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Dosing ProtocolSexual Health / Libido

Educational reference only. Individual responses vary. Consult healthcare provider before use.

Vial Size
10 mg
Reconstitution
2 ml BAC water
Dose
500 mcg (10 units on 1ml syringe)
Timing
30 minutes before sexual activity
Frequency
As needed
Duration
As needed
Protocol Notes
FDA-approved as Vyleesi (at 1.75 mg) for HSDD in women. Works centrally via MC3R/MC4R receptors. Common side effects: nausea, flushing, headache.

Why This Dosing Protocol

Why as-needed? PT-141 is used for acute episodes, not daily maintenance. The 45-minute onset allows planning ahead.

Why max once per 24 hours / 8x per month? Melanocortin receptor desensitization occurs with frequent use. Limiting frequency preserves efficacy and reduces side effects. Also, PT-141 can transiently increase blood pressure.
Full Dosing GuideReconstitution CalculatorCycle Cost Calculator

Reconstitution Calculator

Dilution math and unit conversions. Prefilled using a common vial size for this peptide.

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Storage & Handling

Storage at a glance

Proper storage temperatures, shelf life, reconstitution best practices, and travel tips for lyophilized and reconstituted peptides.

Powder: Freezer
1+ year at -20°C
Reconstituted: Fridge
4 weeks max at 2-8°C
View Complete Storage Guide

Handling specifics

Educational overview on storage, labeling, and traceability considerations for lab environments. Consult primary literature and vendor documentation for specifics.

Powder storage (very stable)
  • Freezer (-20°C): 1+ year
  • Refrigerator (2-8°C): 1-3 months
  • Room temperature: 2-3 weeks (emergency only)
Reconstituted storage (fragile)
  • MUST refrigerate at 2-8°C
  • 4-week maximum shelf life
  • NEVER freeze after reconstitution
  • Use bacteriostatic water for multi-dose
Molecular Structure

PT-141 sequence

Click any residue to see its properties.

HydrophobicPolarAcidic (−)Basic (+)Special

Sequence-derived properties

Length
5 residues
Molecular weight
772.9 Da
backbone only
Avg hydrophobicity
-1.94
Kyte–Doolittle scale

Residue classes

Hydrophobic: 2 (40%)Basic (+): 3 (60%)

Net charge distribution

Positive3 (60%)
Neutral2 (40%)
Negative0 (0%)

Amino acid frequency

F×1H×1K×1R×1W×1

Modifications

  • Cyclic structure (lactam)
  • D-Phe at position 7
  • N-terminal acetylation

Sequence and properties provided for educational reference. Not for clinical dosing decisions.

  • Type: Synthetic Peptide
    (7 amino acids)
  • Brand Name: Vyleesi
    (FDA-approved 2019)
  • Receptors: MC3R / MC4R
    (Melanocortin receptors)
  • Onset: ~45 minutes
    (On-demand dosing)
Mechanism
PT-141 → MC3R/MC4R activation → Central nervous system → Sexual desire pathways
Unlike PDE5 inhibitors (Viagra), PT-141 targets desire rather than blood flow. Common side effects include nausea (~40%), flushing, and headache. Max 8 doses/month recommended.
Key takeaway: PT-141 represents a new class of sexual dysfunction treatment that works on desire pathways in the brain, offering an option for those who don't respond to traditional treatments.

FAQ

What is PT-141 and how does it work?

PT-141 (Bremelanotide) is a synthetic peptide that activates melanocortin receptors (MC3R and MC4R) in the brain. Unlike Viagra or Cialis which increase blood flow, PT-141 works centrally to increase sexual desire and arousal. It was derived from Melanotan II and is FDA-approved under the brand name Vyleesi for treating hypoactive sexual desire disorder (HSDD) in premenopausal women.

How is PT-141 different from Viagra?

Viagra (sildenafil) and similar PDE5 inhibitors work by increasing blood flow to enhance physical response. PT-141 works in the brain on melanocortin receptors to increase sexual desire itself. This makes PT-141 effective for people whose issue is low libido rather than physical arousal problems. PT-141 can work for both men and women, while Viagra is only approved for men.

What are the side effects of PT-141?

The most common side effect is nausea, which affects about 40% of users. Other side effects include flushing, headache, and injection site reactions. PT-141 can cause transient increases in blood pressure, so it's not recommended for people with uncontrolled hypertension or cardiovascular disease. The FDA recommends no more than 8 doses per month.

How long does PT-141 take to work?

PT-141 is typically administered about 45 minutes before anticipated sexual activity. Effects can last for several hours. Unlike daily medications, it's used on an as-needed basis. Most users report effects beginning within 30-60 minutes of injection, with peak effects occurring around 1-2 hours.

Is PT-141 FDA approved?

Yes, PT-141 (as Vyleesi/bremelanotide) received FDA approval in June 2019 for treating hypoactive sexual desire disorder (HSDD) in premenopausal women. It's the first FDA-approved treatment that targets brain pathways for sexual desire. It's administered as a subcutaneous injection via an autoinjector pen.

How long does reconstituted peptide last?

Once mixed with bacteriostatic water, peptides remain stable for up to 4 weeks when refrigerated at 2-8°C (36-46°F). Unopened powder can last 1+ year in the freezer. Get our complete Storage & Travel Guide.

Is this peptide legal to purchase?

Peptides sold "for research purposes only" are legal to purchase in the US, but are not FDA-approved for human use outside of specific medical applications. Always consult a healthcare provider before use.

New to peptides?

Take our Peptide Match tool to find the best peptide for your goals. You can also read our Complete Guide to Peptides to learn the basics.

Scientific Sources

The following peer-reviewed studies and official resources provide additional scientific context for this peptide:

PT-141 Research Articles

guides

PT-141 Dosage Chart: 500mcg On-Demand Protocol

Timing matters more than dose — too early and effects fade. Covers 500mcg starting dose, FDA data, and nausea management.

side-effects

PT-141 Side Effects: Nausea, Flushing, BP Changes

Nausea hits 40% of Phase 3 participants. Flushing and BP elevation follow. Full FDA-label safety breakdown.

guides

Buy PT-141: Compare 5 Vendors, From $37

Compare 5 PT-141 vendors side by side: from $37 a vial, best value $3.70/mg. Codes save up to 50%. Vial sizes, COA status, real cost per week.

results

PT-141 Results: What to Expect & When

First effects hit in 15-30 minutes — but nausea often arrives first. Realistic timeline from dose one through repeated use.

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Side-by-side mechanism, dose, half-life, and vendor pricing.

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Disclosure: we may earn affiliate commission from qualifying purchases. Educational information only — not medical advice.