Melanotan Dosage in the Research Literature
Phase I Dose-Escalation Data
melanotan dosage in human studies derives from a small number of Phase I trials. Three trials constitute the entirety of controlled human dose data for MT-II.
Dorr 1996 — first Phase I dose escalation
0.01–0.03 mg/kg / 5-day escalation
The 1996 Dorr pilot study — the first controlled human study of MT-II — used a 5-day dose escalation in 3 healthy males: 0.01, 0.015, 0.02, 0.025, and 0.03 mg/kg/day subcutaneous.[3] Measurable pigmentation increases were observed in 2 of 3 subjects. Nausea and somnolence were reported at higher dose levels within that escalation range.
Wessells 1998–2000 — standardized ED dose
0.025 mg/kg single injection
Subsequent ED trials by Wessells et al. (1998, 2000) standardized the dose at 0.025 mg/kg subcutaneous for the controlled crossover design — a dose that produced erections in 8 of 10 (psychogenic ED)[5] and 17 of 20 (organic ED)[6] subjects. The 2000 organic ED crossover trial in 10 men replicated the 0.025 mg/kg dose and confirmed erection duration approximately 45 minutes vs. 1.9 minutes for placebo.[7]
Those three trials constitute the entirety of controlled human dose data for Melanotan II. No Phase II or Phase III trials for MT-II in any indication have been completed.
Onset Timeline in Research Studies
Controlled vs. self-reported onset data
2–4 weeks colorimetric (Phase I)
In Phase I trials, objective colorimetric pigmentation increases were measurable at 2–4 weeks of daily subcutaneous dosing.[3] Subjective reports of tanning in self-administered, uncontrolled populations typically describe within-week changes — consistent with early eumelanin upregulation in response to MC1R activation, which can precede measurable colorimetric change. The 2021 qualitative analysis of 623 online forum entries from 205 MT-II users confirmed earlier perceived onset in unmonitored self-administration.[23]
Note: self-reported onset data from uncontrolled populations reflects variable doses, inconsistent UV exposure, and unverified compound identity. Only the Phase I Dorr data provides controlled onset measurement.
How Long Does the Pigmentation Effect Persist?
Post-cessation pigmentation persistence
4–6 weeks post-cessation (Dorr 1996)
In the Dorr 1996 Phase I trial, pigmentation increases were still measurable 4–6 weeks after the last dose; the duration was variable and correlated with baseline Fitzpatrick skin type.[3]
The mechanism: plasma clearance of both MT-I and MT-II is rapid (beta half-life <2 hours for MT-I in humans subcutaneous[17]; biphasic rapid clearance for MT-II in rats IV[18]), but melanin synthesis continues after peptide clearance. The cAMP/PKA/CREB/MITF cascade drives sustained tyrosinase expression, and melanin production continues until that expression normalizes.
Research does not support permanent pigmentation. Melanin production returns toward baseline after cessation; continued UV exposure or re-dosing appears necessary to maintain elevated pigment levels.
Reversal timeline — case report evidence
3 months partial reversal (Sivyer 2012)
The 2012 Sivyer case report of a 16-year-old with FAMMM syndrome who self-injected MT-II noted that moles lightened and skin color paled three months after cessation.[14] The 2026 Bonchev case report (400 µg every other day, 64 days cumulative) documented partial reversal of oral mucosal pigmentation by 28 days post-cessation, with gingival pigmentation persisting with reduced intensity at 3 months.[24]
Pharmacokinetics and Half-Life
MT-I PK in humans — Ugwu et al. 1997
t½ 0.8–1.7 h / oral BA undetectable
Absorption phase half-life 0.07–0.79 hours; beta-phase half-life 0.8–1.7 hours subcutaneous; systemic clearance 0.12–0.19 L/kg/h; oral bioavailability: undetectable.[17] Pigmentation effects persisted 3 weeks after final dose despite rapid peptide clearance, confirming that melanin synthesis continues substantially after the peptide has cleared plasma.
MT-II PK in rats — Ugwu et al. 1994
biphasic IV clearance (rat)
IV administration (0.3 mg/kg): biphasic plasma disposition confirmed by both HPLC and bioassay methods; rapid multi-compartment clearance.[18] Both compounds show rapid plasma clearance that contrasts sharply with sustained downstream melanin synthesis.
Oral route: 4.6% oral bioavailability for MT-II in rats[1]; undetectable for MT-I in humans.[17] The oral route is not viable for research use.
Melanotan Administration Routes: Injection vs. Nasal Spray
Routes studied in the published literature differ substantially in the evidence base available. Subcutaneous injection has Phase I trial data; nasal spray does not and carries specific regulatory warnings.
Subcutaneous injection — primary research route
All Phase I human trials
Intranasal spray — no controlled trial data; mucosal melanoma case report
HPRA + MHRA warnings / case report 2025
Documented in self-administration case reports only — not in any controlled trial. A 2025 case report documented a 22-year-old female who developed mucosal malignant melanoma of the anterior maxilla following use of unlicensed MT-II nasal spray for cosmetic tanning.[25] No safety data from controlled trials exists for this route. The HPRA (Ireland) and MHRA (UK) have issued specific warnings regarding unlicensed MT-II nasal spray products.
Subcutaneous biodegradable implant — afamelanotide approved route
16 mg / 60–120 day release
The approved route for afamelanotide (Scenesse) in EPP. A 16 mg implant releases MT-I slowly over 60–120 days, producing sustained plasma levels without the peak-and-trough kinetics of injection.[15]
Reconstitution in Research Protocols
Standard laboratory reconstitution procedure
1–2 mg/mL in bacteriostatic water
Laboratory protocols for lyophilized MT-II powder typically use bacteriostatic water for reconstitution at 1–2 mg/mL concentrations. Reconstituted solutions are stored at 4°C per standard peptide laboratory protocols and used within the timeframes specified in published study protocols.
The cyclic structure of MT-II confers greater enzymatic resistance than linear alpha-MSH, but lyophilized storage at controlled temperature is standard practice for all peptide research compounds. Freeze-thaw cycling degrades peptide integrity; standard protocols minimize this.