Peptides
Melanotan II
Also called MT-II · MT2 · Melanotan 2 · Melanotan II Acetate
Melanotan II is sought for a darker tan and sometimes for sexual effects. Small human studies observed both, alongside nausea and unwanted erections. The practical trade-off is that visible pigmentation does not establish a safe tanning routine or protection from UV damage.
Dosage & duration
Early research context only; no established cosmetic loading or maintenance schedule.
Dorr phase-I tanning experiment
Published example · product-specific- Dose
- 0.01 mg/kg initially; escalated up to 0.025–0.03 mg/kg
- How often
- Subcutaneous injections on alternating study weekdays
- How long
- 5 active injections over 2 weeks
Only three male volunteers; not a suggested personal regimen.
Sources: 5
Pigment and other effects
A darker tan comes with more than a skin effect
Small early studies observed pigmentation and erections; they did not establish a safe cosmetic routine.
Why people seek it
-
More pigment
A darker tan is the main cosmetic goal.
-
Sexual effects
Erectile effects also attract interest, but may be unwanted.
What can get in the way
-
Nausea and fatigue
Both occurred in the early human experiments.
-
Skin and erection concerns
Mole changes and prolonged erections need attention.
Why people use it
Tanning is the main draw; sexual effects are another reason it gets discussed. Early experiments support an effect on pigment and erections, but not the safety of repeated cosmetic use.
Loading and maintenance claims
Online schedules differ widely. The early trial below was a small supervised experiment, not evidence for a long-term loading-and-maintenance plan. A stronger dose should not be assumed to mean a better or safer tan.
Side effects worth recognizing
Nausea, yawning and appetite changes occurred in human experiments. A prolonged erection can be an emergency: one lasting four hours needs urgent care. Skin or mole changes deserve assessment, and tanning products do not replace UV protection.
Model details: Melanotan II · relative timing
Compare timing and buildup for this compound. The values are not blood concentrations or a measure of strength.
Shows a relative timing scenario; absolute blood concentrations are not calibrated.
Timing assumptions and sources
The historical 2.4 h value remains an illustrative timing assumption, not a confirmed human terminal half-life.
One 1 mg input peaks at 1 relative unit after a single dose. Other amounts scale proportionally; overlapping doses add when accumulation is on. Different compounds use separate relative scales.
- Timing half-life used
- 2.4 hours
- Absorption half-life assumed
- 0.6 hours
- Reference amount for the relative scale
- 1 mg
- Absorption half-life is assumed to be one quarter of the slower timescale (0.6 h); it is not a measured absorption parameter.
- A single 1-unit input has a peak of 1 relative unit; scaling and repeated-dose addition are mathematical assumptions. This normalization is independent of the example dose.
- Do not borrow bremelanotide parameters simply because the molecules are related.
- Erection duration is a pharmacodynamic outcome, not plasma half-life.
- Failure to recover a human PK dataset is an evidence gap, not proof that no study can exist.
- Dorr et al. 1996 melanotan-II pilot phase I
The three-man SC phase I pilot measured pigmentation and tolerability. Its accessible abstract supplies no matched plasma Cmax, reference dose and Tmax calibration.
- Ugwu et al. 1994 melanotan-II preformulation study
Rat oral availability of 4.6% does not establish human SC availability.
melanotan-ii-relative-timing-2026-10 · version 1
Common questions
Does Melanotan II replace sunscreen?
No. A darker appearance does not establish adequate UV protection.
Is Melanotan II the same as PT-141?
No. Bremelanotide/PT-141 is a different medicine with its own indication, dose and precautions.
Sources Labels, studies and notes behind this guide
Catalog evidence: Other human research. This describes the type of evidence, not a clinical review of every claim.
Summary and fact source checks: 2026-10-07. This records source checking, not medical review of the whole page.
Notes on the quick facts
- Main goal
- An observed effect, not evidence of sun protection.
- Trade-off
- Sexual effects can occur even when tanning is the goal.
- 1. Dorr et al.: phase-I Melanotan-II study
Original placebo-controlled pilot in three male volunteers, testing pigmentation and tolerability. Very small early human study, not long-term safety evidence.
- 2. Wessells et al.: MT-II crossover study
Ten men with psychogenic ED; erectile responses and transient nausea/yawning/appetite effects. Not a general sexual-wellness or tanning regimen.
- 3. Clinical case report: melanotan-associated priapism
Original case report illustrates serious prolonged erection after MT-II; a case does not measure incidence or prove every product’s composition.
- 4. TGA: warning about melanotan tanning products
Regulator states melanotan is not approved as a tanning agent in Australia and warns of unapproved online products. Jurisdiction-specific statement; not a claim about every worldwide approval.
- 5. Dorr et al.: early MT-II pigmentation trial
Three men, escalating SC doses over five alternate-day injections; early experiment, not established tanning regimen.
- 6. Dorr et al. 1996 melanotan-II pilot phase I
The three-man SC phase I pilot measured pigmentation and tolerability. Its accessible abstract supplies no matched plasma Cmax, reference dose and Tmax calibration.
- 7. Ugwu et al. 1994 melanotan-II preformulation study
Rat oral availability of 4.6% does not establish human SC availability.
Keep reading
Related compounds and examples
Related compounds
Melanotan I (Afamelanotide)
Melanotan I attracts people who want a darker tan. Its medicine form, afamelanotide, is used for a rare light-sensitivity disorder; the approved implant is very different from tanning powders sold online. A tan does not replace sun protection.
PT-141 (Bremelanotide)
PT-141 is researched for low sexual desire. As VYLEESI, bremelanotide is an on-demand treatment for acquired, generalized low desire causing distress in premenopausal women. It is not a general performance enhancer, and nausea is a common trade-off.
Oxytocin
Oxytocin gets attention as a “bonding hormone” and possible libido aid. A nasal-spray trial in women did not outperform placebo for sexual dysfunction. Its established medical use is different: supervised labor and postpartum care.