What is PT-141?
PT-141 is a synthetic peptide derivative of alpha-melanocyte-stimulating hormone (α-MSH). It was originally discovered as a metabolite of Melanotan-2 during tanning research. While its parent molecule (MT-2) was studied for skin pigmentation, PT-141 was specifically isolated for its profound effects on sexual arousal and desire.
Technically, it is a non-selective melanocortin receptor agonist, but its primary research focus is its activity at the **MC4R** receptor in the brain, which regulates sexual motivation and energy balance.
⚗️ Key Research Facts
- Molecular Class: Melanocortin Receptor Agonist
- Primary Target: MC4R (Central Nervous System)
- Status: FDA Approved (as Vyleesi) for HSDD
- Route: Subcutaneous Injection
Mechanism: The MC4R Pathway
Most common treatments for sexual dysfunction (like PDE5 inhibitors) work by increasing local blood flow to the genitals. PT-141 is different because it targets the **brain**.
Activating the Hypothalamus
PT-141 binds to MC4R receptors in the hypothalamus, a region of the brain that coordinates autonomic and endocrine responses. This activation triggers downstream signals that increase sexual desire and arousal, potentially by modulating dopamine levels in the reward centers of the brain.
FDA Approval & Vyleesi
In 2019, the FDA approved Bremelanotide (the pharmaceutical name for PT-141) under the brand name **Vyleesi**. It is specifically indicated for the treatment of acquired, generalized Hypoactive Sexual Desire Disorder (HSDD) in premenopausal women.
This approval confirmed PT-141's effectiveness in increasing sexual desire and reducing the distress associated with low libido, cementing its role as a valid therapeutic tool in reproductive endocrinology.
PT-141 vs. Melanotan-2
Although they share a common lineage, researchers distinguish them for specific goals:
- Melanotan-2: Highly non-selective. Affects MC1R (tanning) and MC4R (libido). Used when both tanning and libido effects are desired.
- PT-141: More targeted for MC4R. Significantly less impact on skin pigmentation, making it the preferred choice for purely sexual health research.
Research Protocols & Dosing
- Administration: Subcutaneous injection.
- Standard Dose: 1.25 mg to 1.75 mg.
- Timing: Usually administered 45 minutes to 2 hours before the intended effect. The peak effect can last for several hours.
- Safety: Can cause a transient increase in blood pressure. Avoid in subjects with uncontrolled hypertension.
- Common Side Effects: Nausea (very common with the first dose), facial flushing, and headache.
Frequently Asked Questions
Does PT-141 work for men?
Yes. While Vyleesi is approved for women, significant research and clinical practice show that PT-141 is highly effective in treating erectile dysfunction and low libido in men, especially those who do not respond to traditional PDE5 inhibitors.
Does it cause tanning?
While it is less melanogenic than MT-2, high-frequency or long-term use of PT-141 can still lead to some skin darkening and freckle prominence in research models.
Where to buy PT-141 in Canada?
Nūmira Peptides offers laboratory-grade PT-141 (Bremelanotide) for research purposes. Shop PT-141 →
