PT-141
Also known as: Bremelanotide · Vyleesi
Contents
MW
1025.18 Da
Amino Acids
7 AA
Half-Life
2-3 hours
Route
SubQ
CAS
189691-06-3
Formula
C50H68N14O10
Amino Acid Sequence
Ac-Nle-cyclo(Asp-His-D-Phe-Arg-Trp-Lys)-OH
Mechanism of Action
PT-141 (Bremelanotide) is a cyclic heptapeptide melanocortin receptor agonist, primarily targeting MC4R. It is FDA-approved as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women.
CENTRAL MECHANISM — MC4R ACTIVATION: Unlike PDE5 inhibitors (sildenafil, tadalafil) which work peripherally on penile blood vessels, PT-141 acts centrally in the brain. MC4R activation in the hypothalamic paraventricular nucleus → dopaminergic signaling in mesolimbic reward pathways → increased sexual desire and arousal.
BOTH SEXES: Works in both men and women by activating the same central arousal pathway. FDA approval is for women (HSDD), but Phase II data exists for male erectile dysfunction.
DERIVED FROM MT-2: PT-141 was developed from Melanotan II research after MT-2's pronounced sexual effects were discovered. PT-141 has improved MC4R selectivity — less tanning and fewer melanocortin side effects than MT-2, though some occur.
VASCULAR-INDEPENDENT: Because the mechanism is central (brain) rather than peripheral (blood vessels), PT-141 may work in patients who don't respond to PDE5 inhibitors.
Dosing Protocol
Low Dose
███ – ███ mcg/day
Standard Dose
███ mcg/day
High Dose
███ – ███ mcg/day
Dosing protocols are for paid members
Get exact dosing ranges, injection frequency, timing rationale, and reconstitution math.
Get Clinical Access — $79/moFrequency
As needed, ≥45 min before sexual activity.
Half-Life
2-3 hours
Reconstitution Guide
Full reconstitution protocol with BAC water volumes, concentration math, and units-to-draw per dose is available on the Clinical plan.
Unlock reconstitution guide →Clinical Warnings
Nausea (40% in trials — most common side effect).
Transient blood pressure increase.
Facial flushing.
Hyperpigmentation with repeated use.
Not for uncontrolled hypertension/CV disease.
Max 8 doses/month per FDA.
Only approved for premenopausal women — male use off-label.
Contraindications
Absolute
Uncontrolled hypertension
Cardiovascular disease
Pregnancy
Relative Cautions
Controlled hypertension
Hepatic impairment
Renal impairment
Side Effect Profile
Mild
- ●Nausea
- ●Flushing
- ●Headache
- ●Injection site reactions
Moderate
- ●Transient hypertension
- ●Skin hyperpigmentation
- ●Vomiting
Severe (Rare)
- ●Severe hypertension
- ●Cardiovascular events in at-risk patients
Synergistic Peptides
Common Stacks
Melanotan II
Research Status
FDA APPROVED (Vyleesi). PMID 31211618 (Clayton 2016): Phase III HSDD RCT — FDA approval basis. PMID 16417600 (Rosen 2004): Erectile function Phase II in men. One of few FDA-approved peptide therapeutics.
Frequently Asked Questions
How does PT-141 work?
PT-141 (Bremelanotide) is a cyclic heptapeptide melanocortin receptor agonist, primarily targeting MC4R. It is FDA-approved as Vyleesi for hypoactive sexual desire disorder (HSDD) in premenopausal women. CENTRAL MECHANISM — MC4R ACTIVATION: Unlike PDE5 inhibitors (sildenafil, tadalafil) which work peripherally on penile blood vessels, PT-141 acts centrally in the brain. MC4R activation in the hypothalamic paraventricular nucleus → dopaminergic signaling in mesolimbic reward pathways → increased
What is the standard dose of PT-141?
PT-141 dosing protocols are available with a ClinPep Clinical subscription. Dosing varies by indication and patient factors — consult a licensed healthcare provider. General frequency: As needed, ≥45 min before sexual activity.
What is the half-life of PT-141?
The half-life of PT-141 is 2-3 hours. This determines optimal dosing frequency and timing.
Who should not use PT-141?
PT-141 is absolutely contraindicated in: Uncontrolled hypertension; Cardiovascular disease; Pregnancy. Use with caution in: Controlled hypertension; Hepatic impairment; Renal impairment.
What are the side effects of PT-141?
Common mild side effects include: Nausea, Flushing, Headache, Injection site reactions. Moderate effects: Transient hypertension, Skin hyperpigmentation, Vomiting.
What peptides stack well with PT-141?
PT-141 is commonly stacked with: Melanotan II, Kisspeptin.
How do you reconstitute PT-141?
PT-141 is reconstituted with bacteriostatic water. Exact volumes, concentrations, and units-to-draw calculations are available in the ClinPep Clinical plan. Always follow your compounding pharmacy's instructions.
How long should you cycle PT-141?
PT-141 cycle protocols vary by indication. Detailed cycle length, on/off schedules, and monitoring guidelines are available with ClinPep Clinical access. Consult your healthcare provider for personalized cycling guidance.
References & Citations
10 PubMed studies · 3 clinical trials
Strategies for Treating Sexual Health Concerns After Breast and Gynecologic Cancer.
Mihulka Olivia, Curran Melissa, Narasimhan Raksha M, Moore Jessica F et al.. Journal of minimally invasive gynecology. 2025
Sexual dysfunction is a common but underrecognized sequelae of breast and gynecologic cancer treatment. Many patients experience symptoms of genitourinary syndrome of menopause, including vaginal dryn
Practical considerations and emerging approaches for the management of vasomotor and sexual symptoms in breast cancer patients on endocrine therapies.
Fuhrman Jessica, Yun Jina, Indorf Amy. Expert review of clinical pharmacology. 2025
Vasomotor symptoms (VMS) and decreased libido are common menopausal symptoms. Patients with breast cancer receiving endocrine therapy experience new or worsening menopausal symptoms. Pharmacologic the
Female Sexual Desire, Arousal, and Orgasmic Dysfunctions: A Systematic Review and Meta-Analysis of Treatment Options.
Toledo Rafaela Germano, Winkelman William D, Reyes-Gonzalez Daniela, Bergeron Sophie et al.. Journal of minimally invasive gynecology. 2026
To conduct a systematic review and meta-analysis of treatments for female sexual desire, arousal, and orgasmic dysfunction in patients without sexual pain conditions. MEDLINE, Embase, Web of Science,
2024 SOGC, 2024 NCCN, 2022 ESO-ESMO, and 2018 ASCO: a comparison of female cancer survivorship guidelines for the management of sexual health concerns.
Bhinder Jashmira K, Kennedy Samantha K F, Faouk Al Aadah Carmen, Al-Khaifi Muna. Supportive care in cancer : official journal of the Multinational Association of Supportive Care in Cancer. 2025
Female cancer survivors often experience sexual dysfunction, which is a significant and increasingly recognized aspect of survivorship. This review compares guidelines from the American Society of Cli
Novel Pharmacologic Treatments of Female Sexual Dysfunction.
How Andrew, Jowdy Christopher, Novatcheva Elli, Clayton Anita H. Clinical obstetrics and gynecology. 2025
This review evaluates pharmacologic treatments for female sexual dysfunction (FSD), focusing on hypoactive sexual desire disorder (HSDD). We provide clinically relevant applications for Food and Drug
Female Syrian hamster analyses of bremelanotide, a US FDA approved drug for the treatment of female hypoactive sexual desire disorder.
Borland Johnathan M, Kohut-Jackson Abigail L, Peyla Anna C, Hall Megan Al et al.. Neuropharmacology. 2025
Hypoactive sexual desire disorder (HSDD) is the most reported sexual dysfunction among premenopausal women worldwide. Bremelanotide, trade name Vyleesi, has been approved by the United States Food and
Gap in Sexual Dysfunction Management Between Male and Female Patients Seen in Primary Care: An Observational Study.
Stanley Elizabeth E, Pfoh Elizabeth, Lipold Laura, Martinez Kathryn. Journal of general internal medicine. 2025
Female sexual dysfunction (FSD), defined as clinically distressing problems with desire, arousal, orgasm, or pain, affects 12% of US women. Despite availability of medications for FSD, primary care ph
Understanding the Interplay Between Premenstrual Dysphoric Disorder (PMDD) and Female Sexual Dysfunction (FSD).
Gollapudi Mahati, Thomas Angelica, Yogarajah Angelina, Ospina David et al.. Cureus. 2024
Premenstrual dysphoric disorder (PMDD) is a severe variant of premenstrual syndrome (PMS), categorized as a mood disorder due to marked symptoms of depression and anxiety, compounded with severe physi
Registered Clinical Trials
Bremelanotide in Premenopausal Women With Female Sexual Arousal Disorder and/or Hypoactive Sexual Desire Disorder
A Phase 3, Bridging, Multicenter, Randomized, Double-blind, Placebo-controlled, Parallel-group Trial to Evaluate the Efficacy and Safety of Subcutaneously Administered Bremelanotide in Premenopausal Women With Hypoactive Sexual Desire Disorder (With or Without Decreased Arousal)
A Phase IIb, Multicenter, Open-Label, Prospective Study of Bremelanotide in Diabetic Kidney Disease
Symptom Indications
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Complete PT-141 Protocol
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This information is for educational and research reference purposes only. ClinPep does not provide medical advice, diagnosis, or treatment recommendations. All protocols should be reviewed by a licensed healthcare provider.