PT-141
Also known as: Bremelanotide
A peptide that boosts sexual desire by acting on the brain's arousal pathways. Unlike pills like Viagra that work on blood flow, this targets the desire and arousal signals in your brain. It's used to help premenopausal women who have low sexual desire.
PT-141 (bremelanotide) is a synthetic melanocortin receptor agonist that is FDA-approved under the brand name Vyleesi for the treatment of hypoactive sexual desire disorder (HSDD) in premenopausal women. It is the only approved pharmaceutical that directly stimulates sexual desire through a central nervous system mechanism, rather than addressing blood flow like PDE5 inhibitors (Viagra, Cialis).
PT-141 works by activating MC4 receptors in the hypothalamus, the brain region that regulates sexual arousal, desire, and behavior. This central mechanism means it can enhance libido and sexual satisfaction independently of genital blood flow. In clinical trials, women with HSDD reported statistically significant increases in desire, arousal, and the number of satisfying sexual events compared to placebo.
The approved dosing is 1.75 mg subcutaneously at least 45 minutes before anticipated sexual activity, with a maximum of 8 doses per month. Common side effects include nausea (about 40%), facial flushing, and headache. Off-label use in men follows similar dosing protocols, though it is not FDA-approved for this indication. PT-141 should not be used by anyone with uncontrolled hypertension or cardiovascular disease.
Dosage
1.75 mg subcutaneous 45+ minutes before activity (max 1 dose/24hr)
Dosages shown are for research reference only. Always consult a qualified healthcare provider.
Administration
Subcutaneous injection (autoinjector)
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Effects
Sexual Desire
FDA-approved for HSDD — uniquely targets central desire pathways, not peripheral mechanics.
Arousal
Works on brain pathways to increase physical arousal alongside desire.
Female Sexual Function
FDA-approved specifically for low sexual desire in premenopausal women.
Mechanism of Action
PT-141 (bremelanotide) is a cyclic heptapeptide derived from Melanotan II through targeted structural modification to shift receptor selectivity toward MC4R and away from MC1R. It was developed specifically to capture the sexual arousal effects observed with MT-II while minimizing the unwanted tanning (MC1R-mediated) effects. The result is a peptide that acts primarily on the central nervous system rather than peripheral vasculature.
PT-141 activates melanocortin 4 receptors (MC4R) in key brain regions involved in sexual function, particularly the medial preoptic area, the paraventricular nucleus of the hypothalamus, and descending autonomic pathways. MC4R is a Gs-coupled GPCR that increases intracellular cAMP, activating neural circuits that regulate sexual desire, arousal, and physiological sexual response. This central mechanism is fundamentally different from PDE5 inhibitors (sildenafil, tadalafil), which work peripherally by enhancing nitric oxide-mediated vasodilation in penile and clitoral erectile tissue. PDE5 inhibitors improve the mechanical response to arousal but do not affect desire; PT-141 acts upstream, enhancing the desire and arousal signals that originate in the brain.
In women with hypoactive sexual desire disorder (HSDD), PT-141 activates these hypothalamic sexual arousal circuits to increase desire, sexual arousal, and genital response. The nausea experienced by approximately 40% of users is attributed to MC4R activation in the area postrema (the vomiting center in the brainstem), which lies outside the blood-brain barrier and is therefore accessible to circulating peptides. The transient blood pressure elevation results from sympathetic nervous system activation downstream of hypothalamic MC4R signaling. PT-141 retains some residual MC1R activity, which can produce mild facial flushing, but at therapeutic doses the tanning effect is minimal compared to MT-II.
Regulatory Status
FDA approved (2019) as Vyleesi for HSDD in premenopausal women. Palatin Technologies. Off-label use in men through compounding pharmacies.
Risks & Safety
Common
nausea (about 40% of users), facial flushing, headache, redness or soreness at the injection site.
Serious
temporary blood pressure spikes, darkening of the skin with repeated use.
Rare
severe nausea that may need anti-nausea medication, dangerous blood pressure spike. Should not be used if you have uncontrolled high blood pressure or heart disease.
Compare PT-141 With
Research Papers
19Published: October 23, 2025
AI Summary
Vasomotor symptoms (VMS) and decreased libido are common menopausal symptoms. Patients with breast cancer receiving endocrine therapy experience new or worsening menopausal symptoms. Pharmacologic therapy for VMS has been centered on selective serotonin reuptake inhibitors and serotonin norepinephrine reuptake inhibitors, gabapentin, and clonidine.
Published: January 18, 2026
AI Summary
To conduct a systematic review and meta-analysis of treatments for female sexual desire, arousal, and orgasmic dysfunction in patients without sexual pain conditions..
Published: August 9, 2025
AI Summary
Despite considerable advances in the systemic delivery of peptides, their susceptibility to gastrointestinal degradation and high molecular weight, which restricts permeability across biological barriers, remain obstacles to oral administration. As a result, most peptide therapies rely on injections to achieve therapeutic effects. Recent studies on a bioinspired suction patch demonstrated posit...
Published: April 13, 2025
AI Summary
Erectile dysfunction (ED) pathophysiology involves complex interactions between vasculogenic, hormonal, and neurological mechanisms, with endothelial dysfunction and oxidative stress playing crucial roles. There is growing interest in intravenous (IV) peptides and amino acids as potential therapeutic options for ED treatment..
Published: February 28, 2025
AI Summary
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 Administration (FDA)-approved medications (flibanserin and bremelanotide) and investigational therapies (Lorexys and testosterone combinations). Detailed study outcomes, safety profiles, and clinic...
Published: March 31, 2025
AI Summary
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 Drug Administration to treat HSDD. However, despite approval, very little is known about its neurobiological mechanism of action.
Published: September 9, 2024
AI Summary
Glioblastoma is the most aggressive form of brain tumor and has a dismal prognosis; therefore, novel therapeutic approaches based on the mechanisms underlying its aggressive nature are urgently required. A growing body of evidence suggests that neurotransmitters play a key role in modulating the biology of glioblastoma; however, the role of melanocortins remains unclear..
Published: February 19, 2025
AI Summary
This review aims to provide an overview of pharmacologic management for hypoactive sexual desire disorder (HSDD) in premenopausal women, with a focus on available agents..
Published: September 25, 2023
AI Summary
A large body of preclinical and clinical data shows that the central melanocortin system is a promising therapeutic target for treating various metabolic disorders such as obesity and cachexia, as well as anorexia nervosa. Setmelanotide, which functions by engaging the central melanocortin circuitry, was approved by the FDA in 2020 for use in certain forms of syndromic obesity. Furthermore, the...
Published: May 20, 2024
AI Summary
Efficacy outcomes are only informative to the extent that they are validated. We examined the measurement properties of efficacy measures from the phase III ("RECONNECT") bremelanotide trials for hypoactive sexual desire disorder (HSDD) in women. Continuous efficacy outcomes, including a) the Female Sexual Function Index (FSFI) and its Desire domain (FSFI-D) and b) the Female Sexual Distress Sc...
Published: September 30, 2022
AI Summary
The discovery of melanocortins in 1916 has resulted in more than 100 years of research focused on these peptides. Extensive studies have elucidated well-established functions of melanocortins mediated by cell surface receptors, including MSHR (melanocyte-stimulating hormone receptor) and ACTHR (adrenocorticotropin receptor). Subsequently, three additional melanocortin receptors (MCRs) were iden...
Published: January 17, 2023
AI Summary
Female sexual response implies a deep intertwining between psychosocial and neurobiological mediators. Regulation of central melanocortin signaling may enhance sexual desire. In premenopausal women with hypoactive sexual desire disorder (HSDD), melanocortin receptor agonist bremelanotide (Vyleesi) has been hypothesized to trigger excitatory brain pathways..
Published: March 24, 2022
AI Summary
Background: Hypoactive sexual desire disorder (HSDD), the most prevalent female sexual dysfunction, is characterized as persistent diminished desire for sexual activity accompanied by distress. The efficacy and safety of bremelanotide, a melanocortin receptor agonist approved by the U.S. Food and Drug Administration for treatment of acquired generalized HSDD in premenopausal women, were establi...
Published: June 14, 2022
AI Summary
The melanocortin 4 receptor (MC4R) plays a central role in appetite regulation, and agonistic activity at this receptor promotes satiety. Results from two randomized controlled clinical trials examine the effects of bremelanotide's agonism at MC4R on caloric intake and body weight..
Published: February 10, 2022
AI Summary
Background: Bremelanotide, a melanocortin receptor agonist, is Food and Drug Administration (FDA)-approved for the treatment of premenopausal women with acquired, generalized hypoactive sexual desire disorder. Methods: Review of bremelanotide's safety profile from the clinical development program (phases 1 through 3). Results: The clinical development program comprised 3500 subjects in 43 compl...
Published: December 11, 2021
AI Summary
The US Food and Drug Administration (FDA) has approved two drugs for 'hypoactive sexual desire disorder' in women, flibanserin (Addyi) in 2015 and bremelanotide (Vyleesi) in 2019. In this paper we examine the outcome measures and clinical trial data upon which regulatory approval was based. In clinical trials, flibanserin led to an average of only one additional enjoyable sexual experience ever...
Published: November 24, 2021
AI Summary
Melanocortin-4 receptor (MC4R) plays a central role in the regulation of energy homeostasis. Its high sequence similarity to other MC receptor family members, low agonist selectivity and the lack of structural information concerning MC4R-specific activation have hampered the development of MC4R-seletive therapeutics to treat obesity. Here, we report four high-resolution structures of full-lengt...
Published: April 8, 2021
AI Summary
Abstract too short to summarize.
Published: March 6, 2021
AI Summary
described results from two 24-week Phase III trials of bremelanotide for treating hypoactive sexual desire disorder (HSDD) in women. 72.72% of protocol-listed outcomes were not reported by Kingsberg et al., who provided results of 15 secondary measures which were not listed in the study protocols. None of their efficacy outcomes were reported in line with CONSORT data reporting standards and no...
Frequently Asked Questions
What is PT-141?
A peptide that boosts sexual desire by acting on the brain's arousal pathways. Unlike pills like Viagra that work on blood flow, this targets the desire and arousal signals in your brain. It's used to help premenopausal women who have low sexual desire.
What is PT-141 used for?
A peptide that boosts sexual desire by acting on the brain's arousal pathways. Unlike pills like Viagra that work on blood flow, this targets the desire and arousal signals in your brain. It's used to help premenopausal women who have low sexual desire.
What is the dosage for PT-141?
FDA-approved: 1.75 mg subcutaneous at least 45 minutes before anticipated sexual activity. Maximum 1 dose per 24 hours, maximum 8 doses per month. Off-label (men): similar dosing subcutaneous as needed.
What are the side effects of PT-141?
Common: nausea (about 40% of users), facial flushing, headache, redness or soreness at the injection site. Serious: temporary blood pressure spikes, darkening of the skin with repeated use. Rare: severe nausea that may need anti-nausea medication, dangerous blood pressure spike. Should not be used if you have uncontrolled high blood pressure or heart disease.
How does PT-141 work?
PT-141 (bremelanotide) is a cyclic heptapeptide derived from Melanotan II through targeted structural modification to shift receptor selectivity toward MC4R and away from MC1R. It was developed specifically to capture the sexual arousal effects observed with MT-II while minimizing the unwanted tanning (MC1R-mediated) effects. The result is a peptide that acts primarily on the central nervous system rather than peripheral vasculature. PT-141 activates melanocortin 4 receptors (MC4R) in key brain regions involved in sexual function, particularly the medial preoptic area, the paraventricular nucleus of the hypothalamus, and descending autonomic pathways. MC4R is a Gs-coupled GPCR that increases intracellular cAMP, activating neural circuits that regulate sexual desire, arousal, and physiological sexual response. This central mechanism is fundamentally different from PDE5 inhibitors (sildenafil, tadalafil), which work peripherally by enhancing nitric oxide-mediated vasodilation in penile and clitoral erectile tissue. PDE5 inhibitors improve the mechanical response to arousal but do not affect desire; PT-141 acts upstream, enhancing the desire and arousal signals that originate in the brain. In women with hypoactive sexual desire disorder (HSDD), PT-141 activates these hypothalamic sexual arousal circuits to increase desire, sexual arousal, and genital response. The nausea experienced by approximately 40% of users is attributed to MC4R activation in the area postrema (the vomiting center in the brainstem), which lies outside the blood-brain barrier and is therefore accessible to circulating peptides. The transient blood pressure elevation results from sympathetic nervous system activation downstream of hypothalamic MC4R signaling. PT-141 retains some residual MC1R activity, which can produce mild facial flushing, but at therapeutic doses the tanning effect is minimal compared to MT-II.
How is PT-141 administered?
PT-141 is administered via subcutaneous injection (autoinjector).
What is the half-life of PT-141?
The half-life of PT-141 is 2.7 hours.
Is PT-141 legal?
FDA approved (2019) as Vyleesi for HSDD in premenopausal women. Palatin Technologies. Off-label use in men through compounding pharmacies.
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