Side-by-side · Research reference

Melanotan-IIvsMT-1

Side-by-side comparison across mechanism, dosage, evidence, side effects, administration, and stack synergies. Citations on every claim where available.

APhase 1HUMAN-REVIEWED9/43 cited

BFDA-ApprovedHUMAN-REVIEWED9/51 cited

Melanotan-II

MC1R + MC4R agonist · Tanning + sexual response

0.25–1.0 mgPer doseDorr 1996

Phase 1Evidence levelDorr 1996

~1 hrHalf-life

SQ · Abdomen · Loading 5–7 days, then maintenance

MT-1

α-MSH Analogue · FDA-Approved

16 mgImplant dose

13 AAPeptide lengthChawathe 2026

2019FDA approval

SQ Implant · 60-Day Release

01Mechanism of Action

Parameter

Melanotan-II

MT-1

Primary target

MC1R (skin) + MC3R + MC4R (CNS sexual / appetite)Dorr 1996

Melanocortin-1 receptor (MC1R) on melanocytesLangan 2010

Pathway

MC1R agonism → melanocyte tyrosinase → eumelanin synthesis. MC4R → autonomic sexual arousal centresDorr 1996 Simerly 2023

α-MSH analogue → MC1R activation → cAMP elevation → MITF transcription → eumelanin synthesis

Downstream effect

Skin darkening, photo-protection, increased sexual desire / spontaneous erectionDorr 1996

Increased melanogenesis, photoprotection, reduced UV sensitivityLangan 2010

Feedback intact?

—

Yes — exogenous MC1R agonism does not suppress endogenous α-MSH production

Origin

Cyclic 7-AA modified α-MSH analog; designed at University of ArizonaDorr 1996

Synthetic 13-AA peptidomimetic with norleucine (position 4) and D-phenylalanine (position 7) substitutions for metabolic stabilityChawathe 2026

Antibody development

—

02Dosage Protocols

Parameter

Melanotan-II

MT-1

Loading phase

0.25–0.5 mg/day SQ × 5–7 daysDorr 1996

Builds up to visible tan.

—

Maintenance

0.5–1.0 mg 1–2×/week

After visible tan develops; supports with UV exposure.

—

Frequency

Daily during loading; 1–2× per week maintenance

Every 60 days

Sustained release implant — no daily administration required.

Lower / starter dose

0.1 mg / day

Conservative starter — assess tolerability for nausea.

—

Evidence basis

Phase 1 + anecdotalDorr 1996

Phase 3 RCT / FDA-approved orphan drug

Duration

8–12 weeks per cycle

Seasonal use (spring–autumn typical)

Aligned with peak UV exposure months.

Reconstitution

Bacteriostatic water; protect from light

—

Timing

Evening preferred (24h tan-development cycle)

—

Half-life

~1 hour plasma; effects on melanocytes persist days

—

Standard dose

—

16 mg subcutaneous implant

FDA-approved formulation (Scenesse).

Indication

—

Erythropoietic protoporphyria (EPP)

Narrow FDA approval — not licensed for cosmetic tanning.

Route

—

Subcutaneous implant — upper arm or abdomen

Stability

—

Norleucine/D-Phe substitutions enhance peptidase resistance

Modified structure vs endogenous α-MSH (Met⁴, L-Phe⁷).

04Side Effects & Safety

Parameter

Melanotan-II

MT-1

Nausea

Common, especially loading phase

Common (>10%) — mild, transient

Flushing

Common transient

—

Spontaneous erection

Common in men — MC4R cross-effectDorr 1996

—

Increased mole / freckle pigmentation

Existing moles darken; new lesions possible

—

Melanoma risk

Theoretical concern — increased melanocyte activity; CAUTION in melanoma history

—

Appetite suppression

MC4R-mediated; mild

—

Pregnancy / OB

Contraindicated

—

Implant site reaction

—

Erythema, bruising, tenderness at insertion site

Hyperpigmentation

—

Generalised tanning (therapeutic effect), darkening of freckles/neviLangan 2010 Habbema 2017

Expected melanogenic response — complicates pigmented lesion surveillance.

Melanocytic changes

—

Rapid pigmentation of existing nevi; new melanocytic lesions reported with unregulated useHabbema 2017

Requires dermatologic monitoring; theoretical melanoma concern with chronic stimulation.

Headache

—

Occasional (MC1R-independent melanocortin effects)

Photosensitivity (paradoxical)

—

Rare phototoxic reactions despite melanin increase

Contamination risk (unregulated)

—

Impurity, infection, blood-borne virus transmission from illicit melanotan productsLangan 2010 Habbema 2017

Applies to internet/gym-sourced 'melanotan' — not FDA-approved Scenesse.

Absolute Contraindications

Melanotan-II

·History of melanoma or atypical mole syndrome
·Pregnancy / breastfeeding
·Active uncontrolled hypertension

MT-1

·Hypersensitivity to afamelanotide or excipients
·Hepatic impairment (no safety data)
·Renal impairment (no safety data)

Relative Contraindications

Melanotan-II

·Significant freckling / dysplastic nevus
·Personal or family melanoma history

MT-1

·History of melanoma or atypical nevi (melanocortin receptor stimulation concern)Habbema 2017
·Pregnancy/lactation (insufficient data)
·Photosensitive dermatoses (other than EPP)

05Administration Protocol

Parameter

Melanotan-II

MT-1

1. Reconstitution

Add 2 mL bacteriostatic water to 10 mg vial → 5 mg/mL = 500 mcg per 0.1 mL. Light-protected.

Performed by trained healthcare provider. Sterile technique. Small incision in upper arm (triceps) or lower abdomen using trocar. 16 mg rod (4 mm × 1.5 cm) inserted subcutaneously.

2. Injection site

SQ — abdomen. Rotate sites.

Pressure applied post-insertion. Sterile dressing × 24 hrs. Avoid strenuous activity for 24–48 hrs to prevent extrusion.

3. Timing

Evening preferred. UV exposure (sunlight or tanning bed) helps develop tan.

Slow biodegradable polymer matrix releases afamelanotide over 60 days, maintaining therapeutic plasma levels without daily dosing.

4. Storage

Lyophilised: refrigerate, light-protected. Reconstituted: refrigerate ≤30 days.

New implant every 60 days during high UV season (spring–autumn in temperate climates). Rotate implant sites to avoid scarring.

5. Needle

29–31G insulin syringe.

Baseline and periodic dermatologic exams to document pigmented lesions. Patient education on self-examination for new/changing nevi.