PT-141

Overview

PT-141 (Bremelanotide) is a cyclic heptapeptide melanocortin receptor agonist derived from Melanotan II. It is FDA-approved as Vyleesi (2019) for hypoactive sexual desire disorder in premenopausal women only.

Mechanism of Action

Non-selective melanocortin receptor agonist (MC1R > MC4R > MC3R > MC5R > MC2R per FDA label). Sexual response is driven by central MC4R activation in the medial preoptic area and paraventricular nucleus of the hypothalamus, modulating dopaminergic and oxytocinergic arousal pathways independently of PDE5/vascular mechanisms.

Research Summary

Bremelanotide received FDA approval in June 2019 (NDA 210557) based on the two Phase III RECONNECT trials reported by Kingsberg, Simon, Clayton, Portman et al. in Obstet Gynecol 2019 (PMID 31599840). Pooled 24-week data showed statistically significant increases in the Female Sexual Function Index desire domain and decreases in the Female Sexual Distress Scale compared with placebo, with long-term 52-week open-label safety reported in the companion paper (PMID 31599847). Earlier clinical programs in men with erectile dysfunction — including intranasal bremelanotide and the subcutaneous sildenafil-salvage study by Safarinejad & Hosseini (J Urol 2008, PMID 18206919) — showed modest efficacy but did not lead to approval in men. Safety monitoring shows transient SBP elevation (~6 mmHg) with reflex bradycardia resolving within ~12 hours; nausea (~40%) is the most common adverse event and typically diminishes with subsequent doses. Focal hyperpigmentation has been reported with repeated use, consistent with MC1R activity.

Vendors selling PT-141

Scored vendors carrying PT-141, ranked by trust grade. Grades are computed from indexed Certificates of Analysis. Full $/mg pricing is on the comparison page.

Prescribers who offer PT-141

141 prescribers in our directory work with PT-141, each confirmed from their own website. Peptides like PT-141 require a prescription from a licensed provider.

Reported Side Effects

• Nausea (most common, ~40%; often dose-limiting)
• Flushing
• Headache
• Injection site reactions
• Transient blood pressure increase (~6 mmHg SBP) with reflex decrease in heart rate
• Focal hyperpigmentation (face, gums, breasts) with repeated dosing

Biomarkers researchers track for PT-141

These biomarkers appear in the research literature as measures of response and safety for this compound.

Compare PT-141 with Others

Research References

• Kingsberg SA, Clayton AH, Portman D, Williams LA, Krop J, Jordan R, Lucas J, Simon JA. Bremelanotide for the Treatment of Hypoactive Sexual Desire Disorder: Two Randomized Phase 3 Trials. Obstet Gynecol. 2019;134(5):899-908. PMID: 31599840.
• Dhillon S, Keam SJ. Bremelanotide: First Approval. Drugs. 2019;79(14):1599-1606. PMID: 31429064.
• VYLEESI (bremelanotide injection) FDA Prescribing Information, NDA 210557, 2019. https://www.accessdata.fda.gov/drugsatfda_docs/label/2019/210557s000lbl.pdf

Frequently asked questions

Has PT-141 been independently lab-tested?

Disclosed Labs has collected 85 Certificates of Analysis (COA) for PT-141 from 14 independent testing labs. 36 vendors have submitted material for testing. Products average 99.7% tested purity across the corpus. Full testing data is available at https://www.disclosedlabs.com/peptides/pt-141/testing.

What is the average purity of PT-141 on the market?

Based on 85 COAs analyzed by Disclosed Labs, PT-141 products average 99.7% (±0.3%) tested purity. Individual vendor results vary; see per-vendor COA data at https://www.disclosedlabs.com/peptides/pt-141/coas.

Which labs have tested PT-141?

Independent labs that have tested PT-141 include: ILS Labs (Grade A). Full lab credibility grades and profiles are at https://www.disclosedlabs.com/labs.

Where can researchers source PT-141?

8 vendors with Disclosed Labs trust grades currently list PT-141, including Glacier Aminos, Peptide Partners, OROS Research. Compare live prices and lab-verified COAs at https://www.disclosedlabs.com/prices/pt-141.

Which prescribers offer PT-141 with a prescription?

141 prescribers in the Disclosed Labs directory work with PT-141, each confirmed from their own website. PT-141 requires a prescription from a licensed provider. Browse them at https://www.disclosedlabs.com/prescribers?peptide=PT-141.

How does PT-141 work?

Non-selective melanocortin receptor agonist (MC1R > MC4R > MC3R > MC5R > MC2R per FDA label). Sexual response is driven by central MC4R activation in the medial preoptic area and paraventricular nucleus of the hypothalamus, modulating dopaminergic and oxytocinergic arousal pathways independently of PDE5/vascular mechanisms.

What does the research say about PT-141?

Bremelanotide received FDA approval in June 2019 (NDA 210557) based on the two Phase III RECONNECT trials reported by Kingsberg, Simon, Clayton, Portman et al. in Obstet Gynecol 2019 (PMID 31599840). Pooled 24-week data showed statistically significant increases in the Female Sexual Function Index desire domain and decreases in the Female Sexual Distress Scale compared with placebo, with long-term 52-week open-label safety reported in the companion paper (PMID 31599847). Earlier clinical programs in men with erectile dysfunction — including intranasal bremelanotide and the subcutaneous sildenafil-salvage study by Safarinejad & Hosseini (J Urol 2008, PMID 18206919) — showed modest efficacy but did not lead to approval in men. Safety monitoring shows transient SBP elevation (~6 mmHg) with reflex bradycardia resolving within ~12 hours; nausea (~40%) is the most common adverse event and typically diminishes with subsequent doses. Focal hyperpigmentation has been reported with repeated use, consistent with MC1R activity.