PT-141
Bremélanotide
PT-141 (Bremelanotide) is a synthetic peptide that acts as an agonist of melanocortin receptors (MC4-R) in the brain. It naturally stimulates sexual desire by activating the neurological centers responsible for arousal, without acting directly on the vascular system. Unlike classic medications, it does not directly induce erection: it awakens desire, arousal, and sexual motivation.
Chemical identity
- Sequence
- Ac-Nle-cyclo[Asp-His-D-Phe-Arg-Trp-Lys]-OH (heptapeptide cyclique)
- Molecular formula
- C50H68N14O10
- Molecular weight
- 1025.2 g/mol
- CAS no.
- 189691-06-3
Purity (HPLC) measures the absence of related impurities; it is distinct from net peptide content, since salts and counter-ions (acetate, TFA) count toward the vial mass. Account for this when computing the real concentration at reconstitution.
Potential benefits
Increased desire
Naturally awakens sexual desire, in both men and women.
Enhances arousal and receptivity
Heightens response to sexual stimulation.
Supports performance
Promotes engagement, confidence, and endurance.
Fast & natural effect
Rapid results without direct vascular effect.
For men and women
Improves desire and satisfaction in both sexes.
Overall well-being
Increases confidence, mood, and general sexual well-being.
Mechanism of action
- PT-141 crosses the blood-brain barrier.
- It binds to MC4-R receptors in the brain, notably in the hypothalamus.
- Activation of neuronal pathways involved in sexual desire and arousal.
- Increase in desire, motivation, and receptivity.
- Enhancement of the sexual experience and satisfaction.
Historical milestones
Research milestones, clinical trials and regulatory steps.
- 1990s
Spun off from Melanotan II
Derived from Melanotan II research at the University of Arizona, it draws attention after unexpected sexual-arousal effects are observed.
- 2000s
Developed by Palatin
Palatin Technologies refines the molecule into a centrally acting melanocortin agonist and first studies it intranasally for erectile dysfunction.
- 2008
Program repurposed
The intranasal erectile-dysfunction program is dropped over blood-pressure increases, in favor of a subcutaneous injection for women.
- 2016
RECONNECT phase III trials
Phase III trials in premenopausal women meet their endpoints for improved desire and reduced distress in hypoactive sexual desire disorder.
- 2019
FDA approval (Vyleesi)
The FDA approves bremelanotide (Vyleesi) on 21 June 2019 for hypoactive sexual desire disorder in premenopausal women.
Evolution over time
Onset of effects: natural arousal and increased desire.
Peak effects: desire, arousal, confidence, endurance.
Total duration of effects (up to 8 hours in some cases).
Recovery recommended before further use.
Dosages & protocol
Reference dosages
0 wk
On demand, ~30 to 60 min before sexual activity (1 to 3 times per week max)
Terminal half-life of about 2.7 hours; effects on desire are felt for several hours after subcutaneous injection.
Difference from Viagra / Cialis
- PT-141 acts on the brain and desire; Viagra/Cialis acts on blood flow.
- PT-141 increases arousal and motivation; Viagra causes an erection without desire.
- PT-141 does not cause automatic erection: sexual stimulation is still needed.
- Natural and progressive effect of PT-141, without direct vascular action.
Populations studied in research
Research work covers subjects of both sexes.
- Men: low libido, lack of desire or motivation, arousal difficulties, reduced sexual confidence.
- Women: low sexual desire (HSDD), difficulty reaching arousal, increased receptivity and satisfaction.
Research protocol rationale
- Starting level: 0.5 mg, 1 to 2 times per week, to assess tolerance.
- Common level 1.0 mg; advanced level up to 1.5 mg, 2 to 3 times per week.
- Do not exceed 2 to 3 injections per week: excess desensitizes the receptors.
- Onset of effects 30 to 60 min; peak effects 1 to 3 h; total duration 4 to 6 h.
- Interval described of about 24 hours before further administration.
Warning signs to watch for
- Chest pain.
- Irregular palpitations.
- Severe dizziness.
- Visual disturbances.
- Allergic reaction or any unusual and persistent reaction.
Usage tips
- Contraindication: uncontrolled hypertension or antihypertensive treatment — PT-141 may lower blood pressure; medical advice required before use.
- Maintain adequate hydration; avoid alcohol before and after injection.
- Do not use on a completely empty stomach.
- Mental and physical stimulation is described as a cofactor of the response.
- Protocols describe seeking the minimum effective dose and respecting timing.
- Rotate injection sites to avoid irritation and lipodystrophy.
Good to know / effects to watch
- Nausea (the most common, often subsides within 15 to 30 min)
- Flushing (temporary facial or body warmth)
- Headaches (mild to moderate, related to vasodilation)
- Lowered blood pressure (rare, may cause dizziness or fatigue)
- Gastric discomfort (mild, rarely observed)
Storage
- Before reconstitution: store the lyophilized powder refrigerated (2-8 °C) or frozen (-20 °C), protected from light and moisture.
- After reconstitution: keep refrigerated (2-8 °C) and use within ~28 days.
- Do not freeze the reconstituted solution; protect it from light and do not leave it at room temperature.
Contraindications
- Uncontrolled hypertension: contraindicated (the product transiently raises blood pressure and lowers heart rate).
- Known cardiovascular disease (coronary disease, prior MI/stroke): contraindicated.
- Pregnancy and breastfeeding: avoid.
- High cardiovascular risk (diabetes, obesity, smoking, treated hypertension): control blood pressure before use, medical advice required.
- May reduce absorption of oral drugs (e.g., naltrexone); do not exceed recommended frequency. Known hypersensitivity: avoid.
Possible synergistic combinations
PDE5 inhibitor: PT-141 + Tadalafil = desire + erection + endurance. Start with low doses to assess tolerance.
Desire & Libido stack: boosts desire, arousal, and hormonal balance.
PT-141 + Maca + Ashwagandha = libido & pleasure; reduces stress and supports hormonal balance.
Supports hormonal balance in the Desire & Libido stack.
Sexual Performance stack: improves erection, endurance, and quality of intercourse.
Complements the Sexual Performance stack for firmer erections and confidence.
Circulation & Pumps stack: optimizes blood flow and congestion.
Improves circulation and sensitivity (Circulation & Pumps stack).
Supports the Circulation & Pumps stack.
Recovery & Confidence stack: fast recovery and stress reduction.
Reduces stress and supports mental confidence (Recovery & Confidence stack).
Promotes relaxation and mental confidence (Recovery & Confidence stack).
Sources & references
Links to external sources (scientific databases, trial registries, authorities). RAL Peptides is not responsible for their content.
⚠ For research use only. NOT intended for use on humans or animals. The values shown are indicative and for informational purposes ; each person reacts differently. This guide does not replace medical advice — consult a healthcare professional if in doubt.