Melanotan I (Afamelanotide) Dosage Guide

Melanotan I (afamelanotide, CUV1647) is a synthetic linear tridecapeptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It is a selective MC1R agonist — meaning it primarily activates the melanocortin-1 receptor (MC1R) responsible for melanogenesis, with minimal activity at MC3R, MC4R, and MC5R. This selectivity gives it a significantly cleaner pharmacological profile compared to the non-selective Melanotan II.

The MC1R receptor is expressed on melanocytes in the skin. When activated by Melanotan I, melanocytes increase production of eumelanin — the dark, photoprotective pigment that absorbs UV radiation and scavenges free radicals. This is fundamentally different from pheomelanin (the reddish-yellow pigment that generates free radicals when exposed to UV). By shifting the melanin ratio toward eumelanin, Melanotan I provides genuine photoprotection beyond mere cosmetic darkening.

Afamelanotide is notable for being one of very few melanocortin peptides with genuine pharmaceutical approval. The FDA approved Scenesse (afamelanotide 16 mg implant) in 2019 for the treatment of erythropoietic protoporphyria (EPP) — a rare genetic condition causing extreme photosensitivity and severe pain upon sunlight exposure. The European Medicines Agency (EMA) approved it in 2014.

Use our Peptide Dosage to calculate your exact dose based on vial size and concentration.

For a comparison with the non-selective melanocortin agonist, see our Melanotan II profile and dosage guide. For the related sexual function peptide derived from MT-II research, see PT-141. New to peptides? Start with the Beginner's Guide to Peptides.

Melanotan I is administered by subcutaneous injection for research use or as a subcutaneous implant (Scenesse) for pharmaceutical use. Research dosing follows a two-phase approach: a loading phase of daily injections to build baseline eumelanin levels, followed by a maintenance phase of less frequent injections to preserve the tan.

Research Injectable Dosing — Loading Phase

Research Injectable Dosing — Maintenance Phase

Pharmaceutical Dosing (Scenesse Implant)

Injection Timing

• Time of day: Evening injections are preferred by most users, as mild nausea (if it occurs) can be slept through
• Relation to meals: Injecting on an empty stomach or 1–2 hours after a light meal reduces nausea risk
• Relation to UV exposure: Inject 2–4 hours before any planned sun exposure for optimal synergy, or the evening before
• Consistency: During loading, inject at approximately the same time each day to maintain steady melanocyte stimulation

Melanotan I is supplied as a lyophilized (freeze-dried) powder, typically in 10 mg vials. You reconstitute it with bacteriostatic water, then draw your dose using an insulin syringe. The concentration depends on how much water you add to the vial.

Quick Reference — 10 mg Vial

Unlike GHRPs such as Hexarelin, Melanotan I does not cause receptor desensitization in the same manner. MC1R does not downregulate as aggressively as GHS-R1a. However, cycling is still recommended for practical and safety reasons: melanin accumulation has diminishing returns over time, and periodic breaks allow skin assessment and reduce cumulative exposure.

Seasonal Cycling (Most Common)

The most practical approach for cosmetic tanning. Align MT-I use with sun exposure seasons and take breaks during winter or low-UV periods when maintaining a tan is less relevant.

Continuous Low-Dose Protocol

For users seeking year-round photoprotection or consistent skin tone. Uses the minimum effective dose during low-UV months to maintain some eumelanin protection without full-dose loading.

• High-UV months (spring/summer): Standard maintenance — 0.5–1 mg every 2–3 days
• Low-UV months (autumn/winter): Reduced maintenance — 0.5 mg once or twice per week
• Note: This is more appropriate for photoprotection goals than pure cosmetic tanning

Event-Based Protocol

For users who want to build a tan for a specific event, vacation, or period of sun exposure. Run a focused loading phase, maintain through the event period, then discontinue.

• Loading: 0.5–1 mg daily for 14–20 days before the event
• During event: 0.5–1 mg every 2 days + moderate UV exposure
• Post-event: Discontinue; tan fades over 4–8 weeks

Common Side Effects

Generally mild and dose-dependent:

• Nausea — the most common side effect, usually mild and less frequent/severe than with MT-II. Most common during the first few days of loading; often resolves with continued use
• Facial flushing — mild, transient warmth and redness of the face shortly after injection. Generally harmless and resolves within 30–60 minutes
• Headache — occasional, typically in the first few days. Usually resolves without intervention
• Fatigue or drowsiness — some users report mild tiredness after injection, which is why evening dosing is preferred
• Injection site reactions — minor redness, soreness, or itching at the injection site. Rotate injection sites to minimize

Notable by absence (compared to Melanotan II):

• No sexual side effects — no spontaneous erections, no sexual arousal changes (MC4R is not significantly activated)
• No appetite suppression — no changes in hunger or food intake (MC4R is not significantly activated)
• Significantly less nausea — a major advantage over MT-II, which commonly causes moderate to severe nausea

Skin Changes — Critical Monitoring Required

Because Melanotan I stimulates melanocyte activity, careful skin monitoring is essential:

• Darkening of existing moles — expected and common. Most existing moles will darken somewhat. This is generally benign but should be monitored
• New moles or freckles — may appear, particularly in sun-exposed areas. Document and monitor any new lesions
• Uneven tanning — areas with more melanocytes (face, arms, genitals) may darken more than other areas. This is a normal variation in melanocyte density
• IMPORTANT: Get a baseline dermatological examination before starting MT-I. Photograph all moles. Report any changes in size, shape, color, borders, or texture to a dermatologist promptly. While eumelanin production is photoprotective, increased melanocyte activity warrants professional monitoring

Contraindications

• Melanoma or history of melanoma — stimulating melanocyte activity in the presence of melanocytic neoplasia is contraindicated. Active melanoma, history of melanoma, or atypical mole syndrome are absolute contraindications
• Pregnancy and breastfeeding — no adequate safety data exists for afamelanotide during pregnancy or nursing. Avoid entirely
• Severe hepatic impairment — afamelanotide undergoes hepatic metabolism. Severe liver dysfunction may alter peptide clearance
• Other active skin cancers — increased melanocyte activity in the setting of active cutaneous malignancy is not recommended
• Known hypersensitivity — allergy to afamelanotide or any component of the formulation
• Addison's disease or other conditions with elevated α-MSH — additional MC1R stimulation may be inappropriate in conditions already characterized by excessive melanocortin signaling

When to Stop or Reduce Dose

• Any suspicious mole changes (asymmetry, border irregularity, color variation, diameter increase, evolving appearance) — stop and see a dermatologist immediately
• Persistent or worsening nausea beyond the first few days of loading
• Severe headache or prolonged facial flushing
• Any allergic reaction (rash, hives, swelling, difficulty breathing) — seek medical attention immediately
• Unexplained fatigue or malaise that persists beyond the initial loading phase