Melanotan I Dosage, half-life & reference guide

Week by week.

What to expect in the first 8 weeks

Onset

1–2 weeks

Peak effect

2–4 weeks

Duration

Loading 10–14 days, then maintenance

1. Day 1–7Clinical

   A gentler start than MT-2

   Commonly reported: mild nausea or a brief facial flush after the first doses, usually less than with Melanotan II, and rarely its yawning or erections. In trials the tan built through a 10-day course and kept deepening for weeks after it, sunscreen or not.

   The science

   In the University of Arizona trials, side effects were minor: nausea and transient facial flushing (Dorr 2004), or occasional GI upset and flushing (Ugwu 1997). Afamelanotide binds predominantly to MC1R, the pigment receptor (Scenesse label), while MT-2's later trials were in erectile dysfunction because it causes erections, along with nausea, yawning and less appetite (Wessells 1998).

   Sources

   • Dorr et al. (2004)
   • Ugwu et al. (1997)
   • FDA Scenesse label (2026)
   • Wessells et al. (1998)

   Updated Oct 2026

2. Day 8–21Clinical

   The tan builds, sun or not

   In the first trial, skin darkened in both poor and good tanners over a 12-day course with sunscreen on throughout, and kept deepening for 1 to 3 weeks after it ended. Sun adds to it: with MT-1, the same tan took less sun.

   The science

   Levine 1991 (JAMA): 28 healthy white men, 10 SubQ injections over 12 days with high-potency sunscreen; darkening in skin types I–II and III–IV, none on placebo; the largest change 1 to 3 weeks after the last injection. Dorr 2004: with sunlight, the MT-1 group's backs tanned more and kept the tan at least 3 weeks longer, and volunteers on sun alone needed 50% more sun time for the same tan.

   Sources

   • Levine et al. (1991)
   • Dorr et al. (2004)

   Updated Oct 2026

3. Day 15+Clinical

   Freckles and moles darken too

   MT-1 darkens all pigmented skin, so freckles and moles get darker along with the tan. The approved implant's label recommends a full-body skin exam twice a year, and new or changing moles are worth a dermatologist's look.

   The science

   Scenesse label (warnings): afamelanotide may lead to generalized increased skin pigmentation and darkening of pre-existing nevi and ephelides; a full body skin examination twice yearly is recommended to monitor pre-existing and new pigmentary lesions. In 15 EPP patients (103 moles) given two implants, moles showed reversible dermoscopic changes with no features suggesting malignancy and no new moles at 12 months (Arisi 2021).

   Sources

   • FDA Scenesse label (2026)
   • Arisi et al. (2021)

   Updated Oct 2026

4. Day 22–90Clinical

   A tan that cut sunburn damage in a trial

   In a 3-month trial in fair-skinned people, three 10-day courses raised skin melanin by about 41% in the most burn-prone and more than halved their sunburn cells after a measured dose of UV. The approved implant's label still asks patients to keep up sun protection: a drug tan doesn't replace sunscreen.

   The science

   Barnetson 2006 (J Invest Dermatol): 65 completers, 0.16 mg/kg SubQ for three 10-day cycles over 3 months; melanin density rose 41% in burn-prone (low-MED) skin vs 12% in high-MED skin; after 3 MED of UV, sunburn cells fell by more than 50% and thymine dimers by 59% in the low-MED group. Scenesse label: maintain sun and light protection measures during treatment.

   Sources

   • Barnetson et al. (2006)
   • FDA Scenesse label (2026)

   Updated Oct 2026

5. Any dayClinical

   What Melanotan I is built on

   Melanotan I is afamelanotide, the one melanotan with an approval: Scenesse, a slow-release 16 mg implant for the light-sensitivity disorder EPP (Europe 2014, US 2019). What the crowd injects for a tan is research-grade powder of the same peptide, unregulated, for a use no regulator has approved.

   The science

   First made at the University of Arizona in 1980, 26 times as potent as α-MSH in a cell assay and resistant to blood enzymes (Sawyer 1980). Human tanning trials followed (Levine 1991; Dorr 2004; Barnetson 2006). In the phase 3 EPP trials, the implant gave more pain-free time in direct sunlight (US trial median 69.4 vs 40.8 hours over 6 months; Langendonk 2015). Injected SubQ it is fully bioavailable; swallowed, no drug reached the blood (Ugwu 1997). No late effects were reported 25 years after the first volunteers or in up to 8 years of continuous EPP use (Minder 2017).

   Sources

   • Sawyer et al. (1980)
   • Levine et al. (1991)
   • Dorr et al. (2004)
   • Barnetson et al. (2006)
   • Langendonk et al. (2015)
   • Ugwu et al. (1997)
   • Minder et al. (2017)

   Updated Oct 2026

6. With Melanotan IIClinical

   How MT-1 differs from MT-2

   Both darken skin through the same pigment receptor, so running them together doubles up on the tan. MT-1 is the linear, tanning-focused one; MT-2, the cyclic one, went on to erectile-dysfunction trials and brings more nausea, yawning and appetite loss.

   The science

   Hadley & Dorr 2006: melanotan I (linear) was tested clinically for tanning, melanotan II (cyclic, truncated) for erectile dysfunction. MT-2 produced erections in 8 of 10 men at 0.025 mg/kg, with nausea, stretching and yawning, and less appetite (Wessells 1998). Afamelanotide binds predominantly to MC1R (Scenesse label); its tanning trials reported nausea and transient flushing (Dorr 2004).

   Sources

   • Hadley & Dorr (2006)
   • Wessells et al. (1998)
   • FDA Scenesse label (2026)
   • Dorr et al. (2004)

   Updated Oct 2026

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Mixing and a typical run.

Safety.

Questions people ask.

Research.

Reference.

Cadence

Daily

Loading: daily for 10–14 days. Maintenance: 1–3 times a week.

Half-life

~0.8–1.7 hours

~0.8–1.7 hours (measured in three people after SubQ injection; the slow-release implant's apparent half-life is about 15 hours, per its label)

Research basis

●●● Established

Clinical trials or FDA-approved use exists