PT-141, also known as bremelanotide, is approved by the US Food and Drug Administration (FDA) and is available as an injection. It is primarily used in premenopausal women that have hypoactive sexual desire disorder (HSDD).
The cause of HSDD is thought to be due to an imbalance between both neurotransmitter and hormone levels in the brain, causing decreased excitation. In particular, neurotransmitters like serotonin, dopamine, and norepinephrine, and hormones like testosterone and estradiol, are implicated in female sexual desire.
Bremelanotide is a melanocortin receptor (MCR) agonist. Melanocortins are naturally-found neuropeptides that contribute to the excitatory pathway involved in the female sexual response system. As an MCR agonist, bremelanotide activates several subtypes of MCR. As such, increased dopamine is released which can elevate sexual desire (1).
Bremelanotide has been well-characterized in the treatment of HSDD, particularly via two identical phase 3, double-blind, randomized, placebo-controlled studies. Over two thousand women were enrolled between the two studies and randomized to either bremelanotide or placebo. Women taking bremelanotide demonstrated significant increases in sexual desire as well as significant decreases in distress related to low libido versus placebo (2).
Some early clinical research also exists in men experiencing erectile dysfunction. In a study, men experienced dose-dependent increases in erectile activity. Additionally, animal models show that PT-141 administration induced penile erections (3).
Bremelanotide is well-characterized in HSDD, specifically in treating female sexual desire and physiologic arousal responses. The clinical studies in these indications provide strong support for its real-world use in improving sexual function. For male sexual dysfunction, the evidence is more moderate and supported by smaller studies. However, the results show promise and the mechanistic rationale for PT-141’s use in improving sexual function is strong.
PT-141 is approved by the FDA under the generic name bremelanotide and the brand name Vyleesi for use in HSDD. It currently is not indicated for any indications outside of that particular use. It is available via prescription only and administered using a subcutaneous injection.
Because it is approved by the FDA, PT-141 does not carry many of the concerns associated with peptide therapies. However, it is sometimes marketed online for other indications such as libido increase or male sexual enhancement. These are off-label or unapproved indications, and thus not backed up by strong clinical evidence.
In the phase III trials in HSDD, the most common side effects occurring in more than ten percent of participants include nausea, headache, and flushing (1). Other side effects can include vomiting or injection site reactions.
Per the Vyleesi label, there are also warnings for transient increases in blood pressure and decreased heart rate. Focal hyperpigmentation can also occur, particularly in individuals with darker skin (3).
PT-141/bremelanotide is safe and effective for use in females experiencing HSDD, with strong clinical evidence supporting its use in this indication. It may also provide benefits in men with sexual dysfunction, although these indications are not approved by the FDA.
The information provided in this article is for educational purposes only and is not intended as medical advice. Many peptides are not FDA-approved for human use outside of limited clinical contexts. These compounds are often obtained through unregulated sources that lack quality control. Studies suggest 30–65% of products may be contaminated or mislabeled, with risks including endotoxins, heavy metals, and incorrect sequences. At Weight Loss & Vitality, we focus on evidence-based, medically supervised therapies.
As of April 21, 2026, regulatory status for many peptides remains under review and may change as additional data and guidance become available.
Understanding peptide therapies can be complex without proper guidance. At Weight Loss & Vitality, our comprehensive peptide programs provide patients with a safe, clinically grounded path forward.
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