Melanotan II (α-MSH Analogue)

Peak Sun

More melanin. Less UV. The biology of tanning — rerouted.

$299 AUD · $9.97/day · 30-day supply

Lyophilised powder vial · Subcutaneous injection · Self-administered

30-day full refund if you don't notice a difference. No return required.

2.5×
Increase in UV-induced melanin production versus placebo in Phase I trial
Dorr et al. · Archives of Dermatology 1994 · University of Arizona
Australian Compounded
4.9 · 847 Reviews
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Mechanism

How Melanotan II Works.

Tanning requires two things: UV exposure and melanin production. MT-II amplifies the melanin side of that equation — so less UV is required to achieve more colour.

Step 01

MC1R Agonism

Activating melanogenesis

Melanotan II is a cyclic analogue of alpha-melanocyte stimulating hormone (α-MSH) — a peptide naturally produced in the pituitary that signals skin melanocytes to produce melanin. MT-II binds melanocortin 1 receptors (MC1R) on melanocytes with higher potency and longer duration than natural α-MSH, triggering melanogenesis — the production of eumelanin, the dark brown pigment responsible for UV protection. The result is an elevated baseline melanin level that responds faster and more deeply to UV exposure.

Step 02

Eumelanin vs Pheomelanin

The type of melanin matters

The skin produces two types of melanin: eumelanin (dark brown — protective, UV-absorbing) and pheomelanin (reddish-yellow — less protective, implicated in UV-induced DNA damage). Fair-skinned individuals produce more pheomelanin relative to eumelanin, which is why they burn instead of tan. MT-II specifically upregulates eumelanin production — shifting the melanin ratio toward the protective type. This is the mechanism by which individuals who normally burn begin to achieve an actual tan.

Step 03

Reduced UV Requirement

Less sun, more colour

A melanocyte primed by MT-II produces more melanin per unit of UV exposure. The Dorr Phase I trial showed 2.5× the melanin production with the same UV dose versus placebo — meaning users achieve equivalent colour with significantly less sun exposure, or deeper colour with the same exposure. For Australians in a high-UV environment, this changes the risk calculus: the tan that required 3 hours of pool time now requires 1 hour, with the same UV protection once the melanin is produced.

Clinical Data

The Research.

These are Melanotan II's published Phase I findings — the compound in Peak Sun.

Dorr et al. · Archives of Dermatology 1994 · University of Arizona Phase I Trial

"Subcutaneous Melanotan-II at 0.025 mg/kg produced significant increases in melanin density across all skin phototypes studied. UV-induced melanin production was increased 2.5-fold versus placebo, with the effect sustained for several weeks following cessation. Subjects achieved pigmentation equivalent to weeks of natural UV exposure within days of combined MT-II and minimal UV exposure."

The Arizona trial was the first human Phase I study of Melanotan II — conducted by the team that originally synthesised the compound. The research was motivated by the hypothesis that a "tanning pill" could reduce UV exposure and melanoma risk in fair-skinned populations. The efficacy data was unambiguous; the compound's development for a pharmaceutical indication was deprioritised due to the availability of self-administration.

Hadley & Dorr · Peptides 2006 · Melanocortin Peptide Review

"MT-II activates all five melanocortin receptor subtypes (MC1R–MC5R), with MC1R driving the primary tanning effect. The compound's higher binding affinity and resistance to degradation versus native α-MSH produces a more sustained and potent melanogenic response. The cyclic structure that confers this stability also explains its additional MC3R/MC4R activity — which is why sexual arousal effects have been reported as a secondary finding in some subjects."

The MC4R activity of MT-II is why Bremelanotide (PT-141 — Peak Libido) was originally derived from Melanotan II. When subjects in the tanning studies reported spontaneous arousal, the compound was optimised for that specific receptor. MT-II retains both effects; PT-141 was engineered to retain only the MC4R effect.

Protocol

The Schedule.

MT-II is used in a loading phase to prime melanocytes, then at lower maintenance dose during UV exposure. Always combine with minimal UV — MT-II amplifies, it doesn't replace.

Phase Duration Dose UV Exposure
Loading Days 1–7 0.5–1mg daily (or every other day) 10–15 min moderate sun — enough to activate the primed melanocytes
Active tanning Weeks 2–4 0.5–1mg before UV exposure 15–20 min — you'll notice accelerated pigmentation development
Maintenance Ongoing 0.5mg 2–3x per week Minimal — colour is maintained at maintenance dose
Off-cycle Weeks at lower dose Pigmentation fades over 4–8 weeks after cessation — natural and gradual

Always use SPF during UV exposure even with MT-II — the amplified melanin provides some additional natural protection, but MT-II does not replace sunscreen. Start at the lowest effective dose. Not medical advice. Consult a healthcare professional before use.

Customer Results

They Ran It.

10,347 Australians
4.9★ · 847 reviews
1-in-3 re-order within 60 days
★★★★★
I'm Scottish-Irish. I've never tanned in my life — I burn, peel, repeat. Two weeks of Sun and 15 minutes a day in the backyard and I have colour I've never had. Not orange. Not fake. Actual tan. I genuinely didn't think this was possible for my skin type.
Connor M. — Melbourne, 31, teacher — Sun (Melanotan II)
★★★★★
I was sceptical — I've tried every self-tan product and nothing looks real. This is different. It's the actual pigment in my skin, not a coating on top of it. People keep asking if I just came back from a holiday. I live in Melbourne. It's winter.
Emma T. — Melbourne, 28, marketing — Sun (Melanotan II)
★★★★★
Running Sun for three months. The nausea in the first week was real but manageable — gone by day 5. After that, smooth sailing. I'm darker than I've ever been with a fraction of the sun exposure I'd normally need. It does what it says.
Josh K. — Brisbane, 36, construction — Sun (Melanotan II)

FAQ

Common Questions.

Yes — but significantly less. MT-II primes your melanocytes to produce more melanin per UV photon. You still need some UV to activate the tanning response — but the amount required is a fraction of what you'd normally need. Most users achieve their target pigmentation with 10–20 minutes of natural sunlight per day during the loading phase, where previously they would have needed hours.
The University of Arizona Phase I trial specifically included fair-skinned participants (Fitzpatrick types I and II) — individuals who normally burn without tanning. The results showed successful melanogenesis in these skin types, shifting their pigmentation response. Eumelanin (the type MT-II produces) provides natural UV protection — so the tanning response is also a protective response. Fair-skinned users should start at the lowest dose and introduce UV gradually.
Yes — this is documented in the original Arizona trials. Melanotan II activates five melanocortin receptors, including MC4R, which is the arousal pathway. This is how PT-141 (Bremelanotide — Peak Libido) was discovered: researchers noticed spontaneous arousal in tanning study subjects and isolated the MC4R activity. MT-II retains this effect at standard doses. PT-141 was specifically engineered to isolate the MC4R effect without the tanning effect. This is neither a side effect nor a marketing claim — it's a documented secondary mechanism of the compound.
The most commonly reported side effect is nausea, particularly in the first 1–2 weeks at loading dose. This is the most consistent finding across the published research and user experience — it is dose-dependent and typically resolves without intervention as the body adapts. Taking the dose before sleep reduces the subjective impact significantly. Facial flushing is also common. Darkening of existing moles or freckles can occur — monitor these and consult a dermatologist if any change appears irregular.
30-day full refund, no return required. The tanning effect is typically visible within 2–3 weeks of loading + minimal UV — you will either notice it or you won't. If you complete the loading phase with appropriate UV exposure and notice no difference in pigmentation within 30 days, we return your $299.
Ships as lyophilised powder in a sterile vial. Reconstitute with bacteriostatic water using a fresh syringe and needle. Administer via subcutaneous injection — the lower abdomen or flank is the most common site. Rotate injection sites session to session. Ships stable at ambient temperature; refrigerate on arrival and use reconstituted solution within 21–28 days.
Standard workplace and roadside drug screens test for recreational substances and common medications — peptides will not appear on these screens. If you compete in a WADA-sanctioned sport, verify the current prohibited list at wada-ama.org before use, as regulations update annually. We recommend confirming with your sport's governing body before any sanctioned competition.