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Peptide Reference Guide
Anti-Aging / Aesthetic

Melanotan II: Evidence, Regulatory Warnings and Dose References

Published by Doserly
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Quick Reference Card

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Identity

Research reference
Melanotan II (MT-II, MT-2) is a synthetic cyclic heptapeptide alpha-MSH analog. It differs from linear Melanotan I/afamelanotide and from bremelanotide/PT-141. [2][5]

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Regulatory context

Research reference
TGA warned in January 2025 that products labelled Melanotan I or II are not approved in Australia for tanning and are illegally promoted online. No approved MT-II medicine label was identified in this refresh. [1]

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Human evidence

Research reference
Human MT-II data are mainly small early studies: three healthy men in a phase 1 tanning study and two 10-man erectile-function crossover studies. [2][3][4]

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Dose uncertainty

Research reference
The clinical studies used 0.01-0.03 mg/kg or 0.025 mg/kg subcutaneous dosing; online vial protocols usually use fixed microgram loading and maintenance schedules. [2][3][8][9][10]

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Main safety themes

Research reference
Nausea, flushing, stretching/yawning, appetite changes, erections, mole darkening and unregulated-product risks dominate the evidence and warnings. [1][2][6][7]

Quick dose reference

Melanotan II has no approved tanning dose. Human research exposures and public tanning protocols should be reviewed separately. Any dosing protocol should be reviewed with a qualified healthcare practitioner.

Injection under the skin (subcutaneous)

Based on clinical study details

Phase 1 pigmentation study

Amount studied
0.01–0.025 mg/kg
Frequency
Weekdays
Duration
2 weeks
Dose adjustment
Escalated by 0.005 mg/kg
Reported range & limits
The monitored pilot escalated 0.01–0.025 mg/kg; 0.03 mg/kg caused limiting adverse effects. This is not a consumer safety ceiling.
Evidence and range contextReview the full source references below.
Phase 1 pigmentation study

Selected as the best human exposure anchor because it was a monitored phase 1 pilot rather than a web tanning protocol.

The 0.03 mg/kg exposure caused limiting adverse effects in the pilot and is not a consumer target.

Injection under the skin (subcutaneous)

Based on clinical study details

Male ED challenge dose

Amount studied
0.025 mg/kg
Frequency
Acute challenge
Duration
Single-session studies
Dose adjustment
None
Reported range & limits
ED challenge studies used 0.025 mg/kg as single-session exposure. They do not establish repeated-use limits or a safe maximum.
Evidence and range contextReview the full source references below.
Male ED challenge dose

Included because ED studies used a clear amount, but this does not validate tanning use or repeated public cycles.

Nausea and other adverse effects were common in these small studies.

Injection under the skin (subcutaneous)

Online sourced dosing details

Reported amount
100–1,000 mcg
Frequency
Once daily during loading
Duration
Loading duration varies
Dose adjustment
Start 100–250 mcg; escalation to 500–1,000 mcg claimed
Reported range & limits
Public subcutaneous rows report 100–1,000 mcg loading-style use. Regulators do not recognize these as effective minimums or safe limits.
Evidence and range contextReview the full source references below.
Public subcutaneous tanning protocol

Included only to document one coherent public subcutaneous loading protocol; regulators warn melanotan tanning products are unapproved.

This follows the Peptide Dosing Protocols subcutaneous loading range. Other public pages list 250–500 mcg daily or 500 mcg every 2–3 days; those are comparisons, not blended averages.

Full Dosing Reference SourcesClinical research, registered studies and online dosing sources, with their context and limitations.

Melanotan II rows separate monitored research dosing from unapproved public tanning protocols.

Dorr phase 1 pilot, healthy men

Starting dose 0.01 mg/kg, escalated by 0.005 mg/kg to 0.025-0.03 mg/kg. [2]

Route, frequency and duration
Subcutaneous MT-II or saline on weekdays for 2 weeks; three normal male volunteers. [2]
Interpretation
Extremely small safety and pigmentation study. The authors recommended 0.025 mg/kg/day for future phase 1 work, not public use.

Dorr phase 1 dose-limiting observation

0.03 mg/kg produced grade II somnolence/fatigue in one of two subjects. [2]

Route, frequency and duration
Same weekday subcutaneous escalation protocol. [2]
Interpretation
Illustrates narrow tolerability information; not enough to define a safe ceiling for unregulated products.

Psychogenic erectile dysfunction crossover study

0.025 mg/kg MT-II. [3]

Route, frequency and duration
Subcutaneous dose compared with vehicle during 6-hour RigiScan monitoring in 10 men. [3]
Interpretation
Erection signal was strong, but nausea, stretching/yawning and appetite decrease occurred more often than placebo.

Organic-risk erectile dysfunction crossover study

0.025 mg/kg MT-II, administered twice per treatment condition. [4]

Route, frequency and duration
Subcutaneous MT-II and vehicle in 10 men; 19 MT-II injections were analyzed. [4]
Interpretation
Erections and desire increased; 4 of 19 injections were associated with severe nausea.

Peptide Dosing Protocols MT-II page

100-250 mcg daily, escalating to 500-1000 mcg; maintenance 1-2 doses per week. [8]

Route, frequency and duration
Online subcutaneous vial framework, often using a 10 mg vial. [8]
Interpretation
Publisher-reported research workflow; not supported by a phase 3 dose-finding program.

MyPeptideMatch 10 mg protocol

250 mcg daily in weeks 1-2; 500 mcg daily in weeks 3-6; 500 mcg every 2-3 days after. [9]

Route, frequency and duration
Online 10 mg vial protocol with 2 mL bacteriostatic-water math. [9]
Interpretation
Consumer-facing dosing chart; includes UV timing language that should not be treated as risk reduction.

Pep-dose 10 mg page

250-1000 mcg/day loading; 500-1000 mcg maintenance; lists 2 mg/day as a safety ceiling. [10]

Route, frequency and duration
Online subcutaneous vial protocol, 3 mL diluent example. [10]
Interpretation
Secondary protocol page. The "ceiling" is publisher language, not a regulatory maximum.

PeptideFox library

250-500 mcg daily for 1-4 weeks. [11]

Route, frequency and duration
Online peptide-library entry for cosmetic use. [11]
Interpretation
Condensed publisher proposal; should be read as what a site reports, not what trials validated.

Expanded search now prioritizes direct Melanotan-II human studies, one active MT-II registry without disclosed dose, regulatory warnings, MT-II safety case reports, illegal-product analyses, public vial protocols and only clearly labeled related bremelanotide context. Unrelated bremelanotide HSDD/lactation registries were removed from the count.

Applicable product labels and human studies carry the most weight. A registry entry does not establish study results. Animal studies, public guides and forums add context; they do not establish a safe human dose limit.

Official product and regulatory sources

Human clinical research

Registered clinical trials

Published evidence reviews

Clinical reference resources

Animal and laboratory research

Public dosing guides and calculators

Why the protocols disagree

The controlled human MT-II literature is tiny, weight-based and short. Popular vial schedules are fixed microgram routines designed around 10 mg vials and syringe math. Those schedules are not a translation of an approved label, because no approved MT-II label exists. [1][2][8][9]

MT-II is also frequently used in pages that cite bremelanotide or afamelanotide evidence. Bremelanotide is a separate approved drug for a narrow HSDD indication in premenopausal women, while afamelanotide is a separate implant for EPP. Neither provides a safety or dose bridge for MT-II tanning use. [5]

What is Melanotan II?

MT-II is a cyclic melanocortin agonist developed from alpha-MSH research. It activates melanocortin pathways involved in pigmentation and central arousal/appetite signaling. The early human literature shows biological activity, but it never became an approved tanning or sexual-function drug. [2][3][4]

The compound sits between two better-defined neighbors: afamelanotide, the linear approved implant for EPP, and bremelanotide, the approved PT-141 product for acquired generalized HSDD in premenopausal women. MT-II is not interchangeable with either. [5]

Mechanism of action

MT-II is described as a non-selective melanocortin receptor agonist. MC1R activation on melanocytes explains pigmentation, while MC3R/MC4R activity is the usual mechanistic explanation for appetite and sexual-arousal observations. The erectile-function studies support central melanocortin activity in humans, but they do not define chronic cosmetic-use safety. [2][3][4]

The molecule is often said to spare MC2R, the ACTH receptor, so it is not framed as a cortisol-stimulating drug. That does not make it benign. Receptor breadth is the reason pigmentation, nausea, appetite, yawning and erectile effects can appear in the same study program. [2][4]

Pathway visualization

Melanotan II skin and central melanocortin pathways, with limited early human evidence and reported adverse effects.

MC1R and central melanocortin biology help explain effects reported in small early studies. These findings do not establish an approved medicine or a safe cosmetic protocol. [1][2][6]

What the clinical evidence shows

Pigmentation study

The 1996 pilot study enrolled only three normal male volunteers. MT-II or saline was injected on alternating weekdays for two weeks. Two participants reached 0.03 mg/kg and one reached 0.025 mg/kg. Mild nausea occurred at most dose levels, erections appeared for 1-5 hours after dosing depending on dose, and two subjects had measurable or visible pigmentation after dosing ended. [2]

That study is important historically, but it is not a modern safety package. It cannot estimate rare events, long-term mole behavior, product-quality risk or chronic dosing risk. [2][6]

Erectile-function studies

In psychogenic erectile dysfunction, 8 of 10 men developed clinically apparent erections after 0.025 mg/kg MT-II. Mean duration of tip rigidity above 80% was 38.0 minutes versus 3.0 minutes with placebo. Side effects included nausea, stretching/yawning and appetite decrease. [3]

In men with organic risk factors, MT-II initiated subjectively reported erections in 12 of 19 injections versus 1 of 21 placebo doses. Tip rigidity above 80% averaged 45.3 minutes versus 1.9 minutes with placebo, but severe nausea occurred with 4 of 19 MT-II injections. [4]

These studies explain why PT-141 development followed MT-II research. They do not make MT-II a substitute for Vyleesi or an approved ED treatment. [4][5]

Safety and product-quality concerns

TGA's 2025 warning is blunt: melanotan tanning products are illegally promoted online, not approved in Australia for tanning and may contain toxic, poor-quality or counterfeit ingredients. The agency lists common effects such as headache, nausea, vomiting, appetite loss and facial redness, and flags more concerning reports including mole/freckle changes, kidney dysfunction and swelling of the brain. [1]

The melanotan review literature reports nausea, darkening of existing nevi, yawning, systemic toxicity and melanoma case presentations, while emphasizing that causality is often hard to determine because products are unregulated and many reports include UV exposure or other confounders. [6][7]

This uncertainty should be stated plainly: case reports do not prove MT-II causes melanoma, but the combination of melanocyte stimulation, mole changes, UV-seeking behavior and unregulated products is a safety signal, not reassurance. [1][6][7]

Connecting research with a useful record

For MT-II, a useful record preserves the exact source of the schedule, product form, route, amount, timing, pigmentation observations, side effects and skin changes. Doserly can keep dose logs, reminders, product notes and observation history together. That does not verify a product or make a community protocol evidence-based, but it reduces the chance that a clinical study dose, a vial calculator and a label for a different drug get mixed.

Doserly Academy provides the deeper context around melanocortin receptors, trial size, regulatory status and why bremelanotide and afamelanotide evidence cannot simply be borrowed for MT-II.

Frequently asked questions

Is Melanotan II approved for tanning?

No approved MT-II tanning medicine label was identified. TGA states melanotan tanning products are not approved in Australia and are being illegally promoted online. [1]

What did the human MT-II trials actually use?

The early trials used weight-based subcutaneous dosing, most often 0.025 mg/kg, in very small groups and short monitoring windows. [2][3][4]

Is MT-II the same as PT-141?

No. Bremelanotide/PT-141 is a separate drug with its own FDA label, dose and HSDD indication. MT-II evidence helped lead to that research line, but the products are not interchangeable. [5]

Does MT-II cause melanoma?

The evidence does not prove causation, but reviews and regulatory warnings describe mole changes, melanoma case reports and product-quality risks. That uncertainty is a reason for caution, not dismissal. [1][6][7]

Do online microgram schedules come from clinical trials?

Not directly. They are community or publisher protocols built around vial sizes and syringe math, while the small clinical trials used weight-based dosing. [2][8][9][10]

References

[1] TGA: Do not risk using tanning products containing melanotan, January 2025

[2] Dorr et al. Evaluation of melanotan-II in a pilot phase 1 study, 1996

[3] Wessells et al. MT-II in psychogenic erectile dysfunction, 1998

[4] Wessells et al. MT-II in organic erectile dysfunction risk factors, 2000

[5] DailyMed: Vyleesi bremelanotide injection label

[6] An unhealthy glow? Review of melanotan use and associated outcomes, 2015

[7] Insights into tanning biology and tanning products, 2026

[8] Peptide Dosing Protocols: Melanotan II guide, 2026

[9] MyPeptideMatch: Melanotan II 10 mg dosing protocol, 2026

[10] Pep-dose: Melanotan II 10 mg protocol

[11] PeptideFox peptide library: Melanotan II listing