Updated August 2026
Melanotan-2 Dosage: Research Evidence, Human Trials, and Study Protocol
Research note: Melanotan-2 (MT-II, cyclic heptapeptide, MW ~1024 Da) has no FDA-approved dose. Human research: 0.010–0.030 mg/kg SC in ~23 unique men; 0.025 mg/kg most repeated. At 75 kg that is ~1.875 mg — not 0.25 mg. Online 0.10–0.50 mg fixed schedules are anecdotal. Broad MC1R/MC3R/MC4R activity → pigmentation and nausea, erections, appetite effects. ≠ afamelanotide · ≠ bremelanotide.
Melanotan-2 is a synthetic cyclic α-MSH analogue with lactam-constrained pharmacophore and broad melanocortin receptor agonism — unlike the more MC1R-focused afamelanotide.
Published human evidence is unusually small: one three-person pigmentation pilot and two ten-person erectile-dysfunction crossover studies (0.025 mg/kg SC). Online tanning protocols use fixed sub-milligram doses on daily loading schedules — not validated equivalents of the trial record.
Central effects (nausea, yawning, erections, somnolence) set the practical dose ceiling alongside pigmentation. No validated intranasal dose, maintenance schedule, or long-term safety exposure exists.
Melanotan-2 dosage in 30 seconds
| Question | Current answer |
|---|---|
| FDA-approved dose | None for MT-II |
| Human research range | 0.010–0.030 mg/kg SC |
| Most repeated study dose | 0.025 mg/kg SC |
| At 75 kg (0.025 mg/kg) | ~1.875 mg per injection |
| Online fixed range | ~0.10–0.50 mg · anecdotal |
| Unique human participants | ~23 men total |
| Intranasal dose | Not validated |
| ≠ | SCENESSE · VYLEESI doses |
Compound identity
Identity gate
MT-II vs afamelanotide · bremelanotide · online vial
This page's subject — cyclic heptapeptide · broad MC1R/MC3R/MC4R/MC5R agonism
MW ~1024.18 Da · PubChem CID 92432 · lactam ring Asp–Lys. Pigmentation plus nausea, yawning, appetite, sexual arousal, erections.
Melanotan-2 is not afamelanotide or bremelanotide
Product comparison
Melanotan-2 vs afamelanotide (SCENESSE) vs bremelanotide (VYLEESI)
| Feature | MT-II | Afamelanotide | Bremelanotide |
|---|---|---|---|
| Structure | Cyclic heptapeptide | Linear 13-mer | Related cyclic heptapeptide |
| MW | ~1024 Da | ~1647 Da | Different terminal chemistry |
| Receptors | MC1R, MC3R, MC4R, MC5R | Predominantly MC1R | Melanocortin agonist (HSDD) |
| U.S. approval | None | SCENESSE (EPP) | VYLEESI (HSDD) |
| Labeled dose | None | 16 mg implant q2mo | 1.75 mg SC as needed |
Dose and unit mathematics
Unit math
nmol ↔ mcg · published mg/kg table (MW ~1024.18 g/mol)
| mg/kg | 60 kg | 75 kg | 90 kg |
|---|---|---|---|
| 0.01 mg/kg | 0.6 mg | 0.75 mg | 0.9 mg |
| 0.015 mg/kg | 0.9 mg | 1.125 mg | 1.35 mg |
| 0.02 mg/kg | 1.2 mg | 1.5 mg | 1.8 mg |
| 0.025 mg/kg | 1.5 mg | 1.875 mg | 2.25 mg |
| 0.03 mg/kg | 1.8 mg | 2.25 mg | 2.7 mg |
≈ mcg
1.02 mcg
Weight-based dose calculator
Weight-based dose
Published mg/kg → total mg per injection
mg/kg
0.025 mg/kg
Total per injection
1.875 mg
(1,875 mcg)
vs 0.25 mg online
7.5×
Online 0.25–0.50 mg fixed doses are substantially below 0.025 mg/kg in most adults — but repeat daily with uncertain product potency.
Regulatory context
No FDA-approved Melanotan-2 product. FDA enforcement describes MT-II marketed as unapproved injectable tanning drug. Australia: prescription-only but no ARTG-listed product; TGA 2026 reported inconsistently dosed nasal sprays.
Dosage in human clinical research
> Study exposure — not a cosmetic, sexual-function, or long-term treatment schedule.
Human clinical research
~23 unique men · 0.010–0.030 mg/kg SC · pigmentation + ED cohorts
| Study | Dose | Route | n | Finding |
|---|---|---|---|---|
| Dorr 1996 pilot | 0.010–0.030 mg/kg | SC weekdays × 2 wk | 3 men | 5 active doses alternating saline; 0.025 mg/kg selected for Phase I |
| Wessells 1998 | 0.025 mg/kg | Single SC · crossover | 10 psychogenic ED | RigiScan erections; dose-related nausea/yawning |
| Wessells 2000 organic | 0.025 mg/kg | SC × 2 crossover | 10 organic ED risk | 12/19 active erections; 4/19 severe nausea |
| Wessells 2000 review | 0.025 mg/kg | Pooled ED cohorts | 20 men (not new) | 17/20 erections; 12.9% severe nausea at this dose |
The 1996 pilot dose escalation
Dorr 1996 pilot
Within-participant escalation 0.010 → 0.030 mg/kg · 3 men
| Step | mg/kg | Reported effects |
|---|---|---|
| Start | 0.01 mg/kg | Transient yawning, GI cramping, flushing |
| +0.005 | 0.015 mg/kg | Generally transient central/GI effects |
| +0.005 | 0.02 mg/kg | Transient effects continue |
| +0.005 | 0.025 mg/kg | Spontaneous partial erections all 3 men · selected for Phase I |
| +0.005 | 0.03 mg/kg | Grade 2 somnolence/fatigue in 1/2 · stretching/yawning up to 10 h |
Five active doses on alternating weekdays over 2 weeks. 0.025 mg/kg chosen for future Phase I — not a population maximum tolerated dose.
0.025 mg/kg was selected for future Phase I work from three men — not proof of safe repeated or unsupervised use.
Human pharmacokinetic gap
Pilot reports establish pharmacodynamics but not a robust modern plasma PK model. Frequently cited '1–2 hour half-life' is largely extrapolated from rat IV studies — not established human SC half-life.
Evidence hierarchy for dose selection
Evidence hierarchy
No approved label · tiny human record · extensive online Tier E
| Tier | Evidence | Use |
|---|---|---|
| Tier A — Approved MT-II label | None | No FDA-reviewed MT-II product |
| Tier B — Controlled human studies | 0.010–0.030 mg/kg SC · ~23 unique men | Studied exposures only |
| Tier C — Case reports / forum research | Priapism, toxicity, lesions | Safety signals · not incidence rates |
| Tier D — Preclinical | Rat PK, feeding models | Mechanism · not human schedule |
| Tier E — Online/commercial | 0.10–0.50 mg fixed · loading/maintenance | Documents practice · not validation |
Commonly reported online protocols
Reported protocols
Online loading/maintenance · Dorr pilot · proposed SAD cohorts
- Amount
- 0.25–0.50 mg SC
- Frequency
- Daily 7–21 days
- Duration
- 1–3 weeks
- Evidence basis
- Anecdotal · below 0.025 mg/kg at 75 kg (~1.875 mg)
Cumulative exposure examples
Cumulative exposure
Pilot mg/kg course vs online fixed-dose loading
Schedule
0.025 mg/kg × 5 doses (75 kg)
1.875 mg per dose × 5
Nominal total
9.38 mg
Lower per-injection online doses can still accumulate with daily repetition and uncertain vial potency.
Anecdotal versus clinically studied dosing
Evidence split
Weight-based mg/kg trials vs fixed mg online schedules
Published human studies
~23 unique men · SC only · small cohorts
- Dose basis
- Weight-based mg/kg
- Range
- 0.010–0.030 mg/kg per injection
- Most repeated
- 0.025 mg/kg
- Schedule
- 5 alternating weekday doses or crossover singles
- Validated maintenance
- None
Online practice
Fixed mg · daily loading · often with UV
- Typical per dose
- 0.10–0.50 mg (sometimes 1 mg)
- vs 0.025 mg/kg at 75 kg
- 1.875 mg trial level
- Frequency
- Daily load then weekly maintenance
- Intranasal
- No validated bioavailability
- Product control
- Often unknown identity/potency
Preclinical research dosage
Preclinical anchors
Rat PK · feeding models — not human dose conversion
| Model | Dose | Route | Outcome |
|---|---|---|---|
| Rat PK | 0.3 mg/kg IV | Single | Terminal t½ ~1.5 h HPLC — not human SC t½ |
| German shepherd | 1 mg SC daily | 3 weeks | Coat darkening — single-animal observation |
| Rat feeding | 2 mg/kg IP | Daily × 4 d | Reduced food intake/fat — not human weight-loss dose |
| Mouse c-Fos | Model-specific | Acute | MC3R/MC4R hypophagia mechanisms |
Mechanism relevant to dosage
Receptor pharmacology
Broad melanocortin agonism — pigment and central effects share exposure
| Pathway | Dose-relevant effect |
|---|---|
| MC1R (melanocytes) | cAMP → tyrosinase → eumelanin · generalized/focal pigmentation |
| MC3R/MC4R (central) | Appetite suppression · yawning · nausea · sexual arousal · erection |
| MC4R autonomic | Potential HR/BP effects — monitored dosing required |
| MC5R / peripheral | Adds uncertainty — MT-II is not subtype-selective |
A dose chosen for pigmentation cannot be assumed to avoid central sexual, autonomic, or appetite effects.
Effects in controlled human studies
Controlled study effects
Nausea, yawning, somnolence, erections — dose context from trials
| Effect | Dose context | Note |
|---|---|---|
| Nausea / GI cramping | Across pilot; severe in part of 0.025 mg/kg ED program | Dose-limiting |
| Yawning / stretching | Dose-related pilot and ED studies | Central MC effect |
| Somnolence / fatigue | Grade 2 in 1/2 at 0.030 mg/kg | Escalation boundary |
| Spontaneous erections | All 3 at 0.025 mg/kg pilot; most in ED cohorts | Priapism risk if prolonged |
| Pigmentation | Pilot + postmarket | Complicates lesion surveillance |
Safety, case reports, and monitoring
Safety monitoring
Study effects · priapism/toxicity case reports · product quality · surveillance
- Controlled studies
- Nausea, yawning, flushing, somnolence at 0.030 mg/kg, spontaneous erections at 0.025 mg/kg in tiny male cohorts
- Priapism
- Erection ≥4 h is emergency. Case report at reported 2 mg SC required surgery. Research: assess at 2 h.
- Product quality
- Labeled 10 mg vials: 4.32–8.84 mg actual MT-II + impurities (Breindahl 2015). Nasal sprays inconsistently dosed (TGA 2026).
- Skin surveillance
- Eruptive nevi, lesion darkening, melanoma case reports — often with UV and uncertain product identity
Dose escalation
Historical escalation: 0.010 → 0.030 mg/kg in three men. Modern design should use cohort-based sentinel dosing below 0.025 mg/kg if pigment PD can be measured. 'Start low and add until tan' is not a research rule.
Complete proposed Phase I research protocol
MT2-SAD/MAD-01: Part A SAD 0.003–0.018 mg/kg (4 cohorts, 6:2) · Part B MAD 0.006/0.012 mg/kg on days 1,3,5,7,9 · 56 participants · UV-free · no home dosing · no nasal route.
Proposed MT2-SAD/MAD-01
Part A SAD 0.003–0.018 mg/kg · Part B MAD 0.006/0.012 mg/kg · 56 participants
Part A — single ascending dose · 6:2 active:placebo per cohort
| Cohort | mg/kg SC once | Max absolute | Randomization |
|---|---|---|---|
| A1 | 0.003 mg/kg | 1.5 mg cap | 6:2 active:placebo |
| A2 | 0.006 mg/kg | 1.5 mg cap | 6:2 |
| A3 | 0.012 mg/kg | 1.5 mg cap | 6:2 |
| A4 | 0.018 mg/kg | 1.5 mg cap | 6:2 |
Part B — multiple ascending dose · days 1, 3, 5, 7, 9
| Cohort | mg/kg SC | Schedule | Randomization |
|---|---|---|---|
| B1 | 0.006 mg/kg | Days 1, 3, 5, 7, 9 | 9:3 |
| B2 | 0.012 mg/kg | Days 1, 3, 5, 7, 9 | 9:3 |
UV-free · inpatient observation · sentinel dosing · deliberately below historical 0.025 mg/kg. Not a personal tanning or injection plan.
Claims versus evidence
Claim checker
Common Melanotan-2 claims vs the evidence record
Melanotan-2 is FDA approved like afamelanotide
False
No MT-II product or dosage has an FDA-approved label. SCENESSE and VYLEESI are separate products.
Dosage evidence ladder
Dosage evidence ladder
No approved dose · tiny human record · serious case-report signals
| Level | Evidence | Status |
|---|---|---|
| Approved product dose | Absent | No FDA MT-II regimen |
| Controlled human dose | 0.010–0.030 mg/kg · ~23 men | Very limited |
| Replicated acute dose | 0.025 mg/kg in 2 ED cohorts | Limited |
| Human PK-defined dose | Absent | No modern SC PK model |
| Long-term repeated dose | Absent | No validated chronic schedule |
| Intranasal dose | Absent | No validated bioavailability |
| Cosmetic loading/maintenance | Online only | Anecdotal |
| Serious safety signals | Case reports | Requires surveillance |
Bottom line
Melanotan-2 human dosing is documented only in ~23 men at 0.010–0.030 mg/kg SC — with 0.025 mg/kg causing spontaneous erections in all three pilot volunteers and severe nausea in part of the ED program.
Online 0.10–0.50 mg fixed loading/maintenance schedules are not validated clinical regimens. A defensible next study uses GMP product, cohort escalation below 0.025 mg/kg, dense PK/PD, and no intentional UV — not consumer vial titration.
No FDA dose · 0.025 mg/kg ≈ 1.875 mg at 75 kg · online 0.25 mg ≠ trial dose · priapism surveillance essential.
Frequently asked questions
Is Melanotan-2 FDA approved?
No MT-II product or dosage has an FDA-approved label. Afamelanotide and bremelanotide have separate approved products.
What dose was used in human trials?
The first pilot used 0.010–0.030 mg/kg SC. Two erectile-function studies used 0.025 mg/kg SC.
Is 0.025 mg/kg a recommended dose?
It was the pilot investigators' selection for later Phase I from three men — not a general recommended dose.
Did trials use 250–500 mcg daily?
Not in cited human trials. Fixed 0.25–0.50 mg schedules come from online protocols.
Is nasal Melanotan-2 equivalent to injection?
No validated intranasal bioavailability. TGA found large content variation in seized nasal products.
Does MT-II require UV to work?
The 1996 pilot documented pigmentation without standardized intentional UV. UV adds independent skin damage risk.
Why does it affect erections and appetite?
Broad MC3R/MC4R central agonism in addition to MC1R-mediated pigmentation.
What is the maximum safe dose?
Not established. Grade 2 somnolence at 0.030 mg/kg in one of two men; serious case reports at reported 2–6 mg fixed doses.
Can it be combined with PT-141 or PDE5 inhibitors?
No validated combined dose. Overlapping priapism, hemodynamic, and nausea risks.
Does a 10 mg vial mean a 10 mg dose?
No. Independent testing found labeled 10 mg vials often contained substantially less MT-II.
References
Dorr RT et al.
MT-II Phase I pilot 19960.010–0.030 mg/kg · 3 men · pigmentation + erections.
Wessells H et al.
MT-II erectile function studies0.025 mg/kg SC · crossover · RigiScan.
FDA
Melanotan II enforcement recordUnapproved injectable tanning drug.
TGA
Melanotan II dosing alert 2026Inconsistent nasal spray content.
Breindahl T et al.
Online vial content analysis4.32–8.84 mg in labeled 10 mg vials.
Gilhooley EJ et al.
Forum qualitative study 2021623 entries · variable dosing behavior.