Melanotan II vs PT-141 (Bremelanotide)
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
Melanotan II
Melanotan II is a synthetic peptide analog of α-MSH with broader receptor activity than Melanotan I. It produces tanning effects and has notable effects on sexual function and appetite suppression.
Full details →PT-141 (Bremelanotide)
PT-141, also known as Bremelanotide, is a synthetic peptide analog of alpha-melanocyte-stimulating hormone. It is the only FDA-approved treatment for hypoactive sexual desire disorder (HSDD) in premenopausal women.
Full details →Side-by-Side Comparison
| Aspect | Melanotan II | PT-141 (Bremelanotide) |
|---|---|---|
| Dose Range | 250 mcg–1 mg | 1.8 mg |
| Frequency | 1x daily | Less than daily |
| Cycle Length | 1–2 weeks | 4–12 weeks |
| Route | subcutaneous | subcutaneous |
| Mechanism | Non-selective melanocortin receptor agonist affecting MC1R (tanning), MC3R and MC4R (sexual function and appetite). This broader activity explains its multiple effects beyond tanning. | PT-141 activates melanocortin receptors (MC3R and MC4R) in the central nervous system, particularly in areas associated with sexual arousal. Unlike PDE5 inhibitors, it works through the nervous system rather than the vascular system. |
| Typical Dosage | Typical protocols: 0.25-0.5mg daily during loading phase for 1-2 weeks, then 0.5-1mg before UV exposure for maintenance. Start low to assess tolerance. | FDA-approved dose: 1.75mg administered subcutaneously at least 45 minutes before anticipated sexual activity. Not to be used more than once within 24 hours or more than 8 times per month. |
| Administration | Subcutaneous injection. Usually combined with UV exposure for tanning effects. Nasal spray formulations exist but have lower bioavailability. | Subcutaneous injection in the abdomen. Available as Vyleesi (commercial product). Research use may involve different dosing protocols. |
| Side Effects | Nausea (common initially), facial flushing, spontaneous erections, increased libido, appetite suppression, and mole darkening. | Common side effects include nausea (40% of users), flushing, headache, and injection site reactions. Transient blood pressure increases may occur. |
| Best For |
Key Differences
Unique to Melanotan II:
Unique to PT-141 (Bremelanotide):
Key Studies
Melanotan II
- Melanotan II nasal spray: a possible risk factor for oral mucosal malignant melanoma?
International journal of oral and maxillofacial surgery, 2025
- Melanotan II User Experience: A Qualitative Study of Online Discussion Forums.
Dermatology (Basel, Switzerland), 2021
- Melanotan II, a melanocortin agonist, partially rescues the impaired thermogenic capacity of pituitary adenylate cyclase-activating polypeptide deficient mice.
Experimental physiology, 2021
PT-141 (Bremelanotide)
- Small Effects, Questionable Outcomes: Bremelanotide for Hypoactive Sexual Desire Disorder.
Journal of sex research, 2024
- Safety Profile of Bremelanotide Across the Clinical Development Program.
Journal of women's health (2002), 2022
- Bremelanotide for Treatment of Female Hypoactive Sexual Desire.
Neurology international, 2022
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