Melanotan I vs Melanotan II
A detailed comparison to help you understand the differences and choose the right peptide for your research goals.
Melanotan I
Melanotan I (afamelanotide) is a synthetic analog of alpha-melanocyte-stimulating hormone (α-MSH). It is FDA-approved as Scenesse for erythropoietic protoporphyria (EPP), a rare genetic disorder causing severe sun sensitivity.
Full details →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 →Side-by-Side Comparison
| Aspect | Melanotan I | Melanotan II |
|---|---|---|
| Dose Range | 250 mcg–500 mcg | 250 mcg–1 mg |
| Frequency | 1x daily | 1x daily |
| Cycle Length | 1–4 weeks | 1–2 weeks |
| Route | subcutaneous | subcutaneous |
| Mechanism | Binds to melanocortin 1 receptors (MC1R) on melanocytes, stimulating eumelanin production. This increases skin pigmentation and provides photoprotection without UV exposure. | Non-selective melanocortin receptor agonist affecting MC1R (tanning), MC3R and MC4R (sexual function and appetite). This broader activity explains its multiple effects beyond tanning. |
| Typical Dosage | Clinical: 16mg implant every 2 months. Research protocols for tanning typically use 0.5-1mg daily for loading, then maintenance dosing. | 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. |
| Administration | FDA-approved form is a subcutaneous implant. Research use involves subcutaneous injection. Often combined with minimal UV exposure to enhance results. | Subcutaneous injection. Usually combined with UV exposure for tanning effects. Nasal spray formulations exist but have lower bioavailability. |
| Side Effects | Nausea (especially initially), facial flushing, fatigue, headache, and darkening of existing moles or freckles. | Nausea (common initially), facial flushing, spontaneous erections, increased libido, appetite suppression, and mole darkening. |
| Best For |
What They Have in Common
Melanotan I, Melanotan II are both commonly used for:
Key Differences
Unique to Melanotan II:
Which Has Stronger Evidence?
| Goal | Melanotan I | Melanotan II |
|---|---|---|
| Skin Health & Aesthetics | high | high |
Key Studies
Melanotan I
- Use of melanotan I and II in the general population.
BMJ (Clinical research ed.), 2009
- Pharmacologic response of a controlled-release PLGA formulation for the alpha-melanocyte stimulating hormone analog, Melanotan-I.
Pharmaceutical research, 2000
- Discovery and development of novel melanogenic drugs. Melanotan-I and -II.
Pharmaceutical biotechnology, 1998
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
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