PT-141 — Peptide Protocol Wiki reference

Comprehensive human safety data may be limited.

Consult the detailed side effects profile for full information.

Is PT-141 FDA approved?

PT-141 is currently in the approved stage.

In the United States, it is classified as FDA-approved prescription drug.

Approved June 21, 2019 as Vyleesi (bremelanotide) for acquired, generalized HSDD in premenopausal women.

Regulations vary by country and may change.

PT-141 (Bremelanotide): Sexual Health Peptide Guide | Peptide Protocol Wiki Skip to main content 🧬 Peptide Protocol Wiki Peptides Side Effects New Learn Directory Tools Blog News About ⌘K ⌘K 🌱 New to Peptides?

Start the 7-step beginner guide Peptides Side Effects New Directory Learn Tools Blog News About PT-141 📋 Overview 🧬 Molecule 🔄 Similar ⚠️ Side Effects 💉 Dosing 🔬 Research 🚨 Risks 👥 Community 📊 Community Data Home Peptides PT-141 Reproductive Health Skin & Hair approved PT-141 Also known as: Bremelanotide, Vyleesi, PT141 Compare with 2 peptide s Research compiled by Peptide Protocol Wiki 📅 Updated February 9, 2026 Citations Verified TL;DR PT-141 (Bremelanotide), marketed as Vyleesi, is a cyclic heptapeptide melanocortin receptor agonist derived from Melanotan-2.

It was approved by the FDA on June 21, 2019, for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women.

PT-141 acts centrally via melanocortin-4 receptors (MC4R) in the hypothalamus to modulate dopaminergic pathways involved in sexual desire and arousal.

It is the only FDA-approved treatment for HSDD that works through central nervous system melanocortin pathways rather than hormonal or vascular mechanisms.

Browse all reproductive peptides → Table of Contents 📌 TL;DR • FDA-approved for hypoactive sexual desire disorder (HSDD) in premenopausal women • Acts on central melanocortin path

ways rather than vascular mechanisms • Derived from Melanotan-2 with improved receptor selectivity • On-demand dosing (administered as needed before anticipated sexual activity) • Unique mechanism distinct from hormonal and PDE5 inhibitor approaches Community-Reported Side Effects Anecdotal ?

📋 Protocol Quick-Reference Treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women (FDA-approved as Vyleesi) 💉 Dosing Amount 1.75 mg Frequency As needed (PRN), at least 45 minutes before anticipated sexual activity Duration Ongoing as needed; no more than 8 doses per month 💊 Administration Route SC Schedule As needed (PRN), at least 45 minutes before anticipated sexual activity Timing At least 45 minutes before anticipated sexual activity; peak plasma at ~1 hour ✓ Rotate injection sites 📅 Cycle Duration Ongoing as needed; no more than 8 doses per month Repeatable Yes Preparation & Storage ✓ Ready-to-use — no reconstitution required Storage: Vyleesi auto-injectors should be stored at 20-25 degrees Celsius (68-77 degrees Fahrenheit).

⚗️ Suggested Bloodwork ( 6 tests) Blood pressure When: Baseline Why: PT-141 causes transient BP increases; baselin

The melanocortin system is an ancient neuroendocrine pathway involved in regulating diverse physiological functions including appetite, energy homeostasis, pigmentation, inflammation, and sexual behavior.

The specific neural pathway involves: MC4R activation in the hypothalamus : PT-141 binds to presynaptic MC4 receptors on neurons in the medial preoptic area (mPOA) of the hypothalamus Dopamine release : MC4R activation stimulates the release of dopamine, an excitatory neurotransmitter that increases sexual motivation Neural circuit modulation : Increased dopaminergic signaling in the nucleus accumbens, medial preoptic area, ventral tegmental area, arcuate nucleus, and the medial and basolateral amygdala modulates the motivational, arousal, and appetitive aspects of sexual behavior Hormonal effects

e assessment essential CBC When: Baseline Why: General health baseline CMP When: Baseline Why: Liver and kidney function (65% renally excreted) Melanocyte assessment (skin exam) When: Baseline Why: MC1R activation can cause focal hyperpigmentation Blood pressure monitoring When: With first few doses Why: Transient BP increase occurs with each dose; verify return to baseline Blood pressure When: Ongoing Why: Transient increases expected; persistent elevation warrants discontinuation ⚠️ Transient increases expected; persistent elevation warrants discontinuation 💡 Key Considerations → Contraindication: Avoid in patients with uncontrolled hypertension or known cardiovascular disease; not for use in postmenopausal women or men (off-label only) Subscribe to unlock this content Get weekly peptide research summaries, new study alerts, and protocol updates — free.

Restore access No thanks, continue reading Related Reading Peptide Melanotan-2 melanocortin receptor agonist Peptide Melanotan-1 alpha-MSH analog for photoprotection Article Melanotan Tanning Peptides: Risks and Research Evidence How PT-141 works at the cellular level Overview of PT-141 benefits and applications Scientific Details Molecular Formula C50H68N14O10 Molecular Weight 1025.18 Da CAS Number 189691-06-3 Sequence Ac-Nle-c[Asp-His-D-Phe-Arg

# PT-141, known by its generic name bremelanotide and marketed under the brand name Vyleesi, is a synthetic cyclic heptapeptide that acts as a non-selective agonist at melanocortin receptors, with particular relevance to the melanocortin-4 receptor (MC4R) in the central nervous system.

It was approved by the U.S.

Food and Drug Administration on June 21, 2019, for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women, making it one of very few FDA-approved treatments for female sexual dysfunction.

The amino acid sequence of PT-141 is: Ac-Nle-c[Asp-His-D-Phe-Arg-Trp-Lys]-OH This cyclic structure, formed by a lactam bridge between the aspartate and lysine side chains, distinguishes PT-141 from its linear parent peptide alpha-MSH and contributes to its improved metabolic stability and receptor selectivity.

Mechanism of Action # Melanocortin Receptor Activation # PT-141 exerts its effects through activation of melanocortin receptors, particularly MC4R in

Early clinical data demonstrated statistically significant improvements in erectile function.

PT-141 binds to and activates multiple melanocortin receptor subtypes: MC1R : Involved in melanogenesis (skin pigmentation) MC3R : Expressed in the hypothalamus, involved in energy balance MC4R : Primary mediator of PT-141's sexual function effects MC5R : Involved in exocrine gland function The MC4R activation in the hypothalamus is the primary mechanism relevant to PT-141's therapeutic effects on sexual desire.

Central Neural Pathways # PT-141 acts in the brain, not at peripheral tissues, which fundamentally distinguishes it from PDE5 inhibitors (sildenafil, tadalafil) that work by increasing blood flow to genital tissues.

: PT-141 administration produces a small increase in circulating LH, FSH, and testosterone levels, suggesting effects on the hypothalamic-pituitary-gonadal axis This central mechanism means that PT-141 addresses the motivational and desire components of sexual function rather than the peripheral arousal response, making it fundamentally different from treatments like sildenafil or testosterone.

Clinical Development and Approval # RECONNECT Phase 3 Trials # The FDA approval of PT-141 was based on two identical Phase 3, randomized, double-blind, placebo-controlled trials known as RECONNECT (Studies 301 and 302).

Key results from the RECONNECT trials: Statistically significant increases in sexual desire compared to placebo (integrated studies: 0.35 increase, P .001) Statistically significant reductions in distress related to low sexual desire (integrated studies: -0.33, P .001) Effect sizes were modest but clinically meaningful The most common adverse event was nausea (40% bremelanotide vs 1.3% placebo) FDA Approval Details # PT-141 (Vyleesi) was approved on June 21, 2019, with the following label specifications: Indication : Acquired, generalized HSDD in premenopausal women Dose : 1.75 mg subcutaneous injection Administration : Self-administered as needed, at least 45 minutes before anticipated sexual activity Maximum frequency : No more than once every 24 hours, no

more than 8 doses per month Route : Subcutaneous injection via single-dose auto-injector Long-Term Extension Studies # A 52-week open-label extension of the RECONNECT trials demonstrated sustained efficacy with a favorable safety profile.

The most common treatment-emergent adverse events during the extension were nausea (40.4%), flushing (20.6%), and headache (12.0%).

However, there are important differences: Feature PT-141 (Bremelanotide) Melanotan-2 Structure Cyclic heptapeptide Linear/cyclic decapeptide Amino acids 7 10 Primary effect Sexual desire (MC4R) Tanning + sexual function FDA status Approved (Vyleesi) Not approved MC1R activity Lower Higher (melanogenesis) Development stage Marketed product Research compound Administration SC auto-injector SC injection The key structural difference is that PT-141 was designed to retain MC4R-mediated sexual function effects while reducing the MC1R-mediated tanning effects that characterized Melanotan-2.

The mechanism in men is the same as in women: central MC4R activation increasing dopaminergic signaling involved in sexual motivation and arousal.

Other Research Areas # Hemorrhagic shock : PT-141's parent compound Melanotan-2 and related melanocortin agonists have been studied for hemorrhagic shock due to melanocortin-mediated cardiovascular effects Inflammation : Melanocortin receptors play roles in inflammatory regulation Obesity : MC4R is involved in appetite and energy homeostasis, though PT-141 is not developed for this indication Safety Profile Summary # The safety profile from clinical trials and post-marketing experience shows: Nausea : The most common adverse event (40% of patients), often decreasing with repeated use Flushing : Reported in approximately 20% of patients Headache : Reported in approximately 11% of patients Blood pressure : Transient increases in systolic (1.9 mmHg) and diastolic (1.7 mmHg) blood pressure, resolving within 12 hours Injection site reactions : Mild local reactions at the injection site Hyperpigmentation : Focal darkening of the skin (face, gingiva, breasts) reported in some patients, related to MC1R activation Evidence Gaps and Limitations # Despite FDA approval, several areas remain incompletely characterized: Long-term safety beyond 52 weeks of use Efficacy in postmenopausal women (not studied in Phase 3 tri

Skin & Hair Cosmetic & Anti-Wrinkle Melanotan-1 Melanotan-1 (Afamelanotide): Approved alpha-MSH analog.

als) Optimal use in combination with other sexual dysfunction treatments Mechanism of action details at the molecular level in human neural circuits Comparative efficacy versus flibanserin (the other FDA-approved HSDD treatment) Male sexual dysfunction applications beyond early Phase 2 data Effects on reproductive outcomes and fertility Key Research Findings # Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials , published in Obstetrics and Gynecology (Kingsberg SA et al., 2019; PMID: 31599840): Pivotal RECONNECT Phase 3 trials demonstrating bremelanotide 1.75 mg SC significantly improves sexual desire and reduces distress in premenopausal women with HSDD compared to placebo.

Statistically significant increase in sexual desire (integrated 0.35 increase, P .001) Statistically significant reduction in HSDD-related distress (integrated -0.33, P .001) 1267 premenopausal women enrolled across two identical trials Safety Profile of Bremelanotide Across the Clinical Development Program , published in Journal of Women's Health (Clayton AH et al., 2022; PMID: 35147466): Comprehensive safety analysis across the bremelanotide clinical development program including Phase 3 trials and open-label extensions.

Demonstrates favorable overall safety profile with primarily mild to moderate adverse events.