peptideInjectableResearch chemicalNot approved by the FDA or any medicines regulator; case reports document rhabdomyolysis and renal infarction after gray-market injection
Melanotan IIBenefits, Dosage & Interactions
Also known as: MT-II
Melanotan II (MT-II) is a synthetic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It was originally developed as a potential therapeutic agent for tanning as it stimulates melanogenesis (melanin production), leading to skin pigmentation. Research on Melanotan II focuses on libido and weight loss.
Researched by DoseRoutine Research TeamReviewed for accuracy by Nicholas Alexander, RSE, SO, PMPLast updated Educational reference only — not medical advice. Always confirm dosing and safety decisions with a licensed clinician.
Evidence: Limited — Human observational or case data only — no randomized trials.
Evidence strengthLimited · 2/4
PreclinicalStrong human evidence
Human observational or case data only — no randomized trials.
Plasma half-life
Not established
Default unit
mg
What published protocols report
Ranges documented in the literature, shown for reference. DoseRoutine does not recommend an amount — your prescriber or the product label sets the dose.
- Route studied
- Self-administered subcutaneous injection is the route documented in reported user cases and toxicity reports
Reported for Melanotan II in the cited sources. Published ranges are not dosing advice.
Mixing Melanotan II: bacteriostatic water and syringe units
The vial arrives as dry powder. How much water you add sets the strength, and the strength sets the mark you draw to on the syringe. The table assumes a 5 mg vial and a 250 mcg example draw on a U-100 insulin syringe, where 100 units is one millilitre. If your vial is a different size, scale it — the arithmetic is the same.
| Bacteriostatic water added | Resulting strength | 250 mcg draws to |
|---|---|---|
| 1 mL | 5 mg/mL | 5 units |
| 2 mL | 2.5 mg/mL | 10 units |
| 3 mL | 1.67 mg/mL | 15 units |
Units, not millilitres. Insulin syringes are marked in units, and mixing up mcg and mg on a peptide label is the single most common error people report. Check the label twice. Run your own vial through the calculator.
Storage and stability
- Before mixing
- Sealed and still as a dry powder, Melanotan II vials are normally kept in the fridge at 2–8 °C, out of light. Short spells at room temperature during shipping are the norm for lyophilized peptides and are not, on their own, a sign the vial is spoiled.
- After mixing
- Once bacteriostatic water goes in, the vial belongs in the fridge and is generally treated as good for about 28 days — that is how long the benzyl alcohol in bacteriostatic water is relied on to hold back bacterial growth. Plain sterile water has no preservative, so a vial mixed with it is a single-session vial. Never freeze a reconstituted vial.
- When to throw it out
- A properly mixed vial is clear. Cloudiness, floating strands, a color change or powder that will not go into solution after gentle swirling all mean the vial should be discarded rather than used. Shaking a peptide vial hard is the usual cause — swirl it, or run the water down the inside wall of the vial instead of onto the powder.
Handling and shelf-life figures describe general practice for lyophilized peptides. They are not a dose and not medical advice — your prescriber or the product label sets the amount.
References & evidence
Documents the Melanotan II entry is written from. Each number matches an inline marker above.
- [1]Melanotan II injection resulting in systemic toxicity and rhabdomyolysisNelson ME, Bryant SM, Aks SE · Clinical Toxicology · 2012 · Peer-reviewed · PMID 23121206
- [2]Melanotan II: a possible cause of renal infarction: review of the literature and case reportPeters B, Hadimeri H, Wahlberg R, Afghahi H · CEN Case Reports · 2020 · Peer-reviewed · PMID 31953620
- [3]Melanotan II User Experience: A Qualitative Study of Online Discussion ForumsGilhooley E, Daly S, McKenna D · Dermatology · 2021 · Peer-reviewed · PMID 34464955
References & Evidence
Sources on this page that document Melanotan II dosing, timing and safety.
- [1]National Center for Biotechnology Information View source
Educational information only — not medical advice. Dose ranges vary by person, indication and prescriber.
What is Melanotan II studied for?
What is Melanotan II?Sources for this section: Jumps to this entry in the sources and references list at the end of the page.
Melanotan II (MT-II) is a synthetic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It was originally developed as a potential therapeutic agent for tanning as it stimulates melanogenesis (melanin production), leading to skin pigmentation. Beyond its effects on skin color, MT-II has also been studied for its potential effects on sexual function and appetite suppression.
MT-II is administered via injection. Its half-life in the body is approximately 33 hours. It is not currently approved by the U.S. Food and Drug Administration (FDA) for human use and is generally acquired and used in research settings or underground markets. While it has been investigated for potential therapeutic applications, its use outside of controlled research is associated with significant safety concerns. (PubChem)
What does the research say about Melanotan II?
Tap a section to expand.
Melanotan II exerts its effects by acting as a non-selective agonist of melanocortin receptors (MCRs), specifically MC1, MC3, MC4, and MC5 receptors. The primary mechanism for its tanning effect involves the MC1 receptor, which is expressed on melanocytes (cells responsible for melanin production). Activation of MC1 by MT-II stimulates the production of eumelanin (dark pigment) and pheomelanin (red/yellow pigment), leading to skin darkening.
Its influence on sexual function is thought to be mediated through the MC4 receptor in the central nervous system. Activation of MC4 receptors has been linked to pro-sexual effects. Similarly, the anoretic (appetite-reducing) effects observed with MT-II are also believed to involve the MC4 receptor, as well as potentially the MC3 receptor. (DrugBank, PubChem)
Source for this section: Sources for How does Melanotan II work?: Jumps to this entry in the sources and references list at the end of the page.
The primary potential benefit for which Melanotan II was investigated is the induction of skin tanning without exposure to harmful ultraviolet (UV) radiation. By stimulating melanin production, it aims to reduce the risk of sunburn and potentially lower the risk of skin cancer associated with UV exposure. (PubChem)
Additionally, some research has explored the potential of Melanotan II to enhance sexual function, particularly in men with erectile dysfunction, due to its action on melanocortin receptors involved in sexual arousal pathways. (DrugBank)
Preliminary studies also suggest a potential for appetite suppression and subsequent weight loss, again mediated by its interaction with melanocortin receptors in the brain. However, these are research findings, and MT-II is not approved for these applications. (DrugBank)
Formal clinical trials investigating Melanotan II have been limited, particularly for its use as a tanning agent. Most available evidence comes from early-phase research studies and anecdotal reports.
Evidence for its tanning effect: Early research, including studies referenced by DrugBank and PubChem, demonstrates that MT-II can stimulate melanin production in humans, leading to visible skin darkening. However, these studies also highlight common side effects.
Evidence for sexual function: Some studies, as detailed by DrugBank, have shown Melanotan II to induce erections in men with psychogenic erectile dysfunction. This effect is thought to be mediated by central melanocortin receptors.
Evidence for appetite suppression: While some animal and limited human studies suggest a role for melanocortin agonists like MT-II in appetite regulation and weight loss, this area is less thoroughly researched than its tanning or sexual effects for MT-II specifically. (DrugBank)
It is critical to note that despite these research findings, the FDA has not approved Melanotan II for any human use due to safety concerns and insufficient long-term data. Its distribution often occurs through unregulated channels.
Common side effects associated with Melanotan II include nausea, flushing, dizziness, increased libido, spontaneous erections (in males), and appetite suppression. Skin-related side effects can include new moles or changes in existing moles, skin darkening, and hyperpigmentation in certain areas, particularly around injection sites. Other reported side effects include fatigue and stomach cramps. Long-term safety data is lacking.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Melanotan II is not approved by the FDA for human use. Its efficacy and safety have not been fully established in long-term controlled clinical trials. Potential risks include the development of new moles or changes to existing moles, which could lead to an increased risk of melanoma, a serious form of skin cancer. There are also concerns regarding the purity and quality of products obtained from unregulated sources, which may contain contaminants or incorrect dosages. The cardiovascular effects, if any, are not well understood.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Due to the lack of FDA approval and extensive safety data, specific contraindications for Melanotan II are not definitively established. However, individuals with a history of melanoma or other skin cancers, pregnant or breastfeeding women, and those with pre-existing cardiovascular conditions, liver disease, or kidney disease should avoid its use. Anyone with a known hypersensitivity to peptides or any components of the preparation should also avoid it. Individuals taking medications that affect blood pressure, heart rate, or hormone levels should exercise extreme caution.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
Given the lack of regulatory oversight and comprehensive safety data for Melanotan II, specific drug interactions are not well documented. However, caution should be exercised when combining MT-II with any other medications or supplements, especially those that affect hormone levels, blood pressure, heart rate, or skin pigmentation. It is especially advisable to avoid combining it with other substances that may influence melanocortin receptors or have unknown effects on skin health.
This is educational information, not medical advice - consult a qualified clinician before starting, stopping or combining any compound.
The typical timing for Melanotan II administration is user-directed and must be set by a licensed clinician. It is an injectable peptide. Its effects on tanning typically manifest over several weeks of consistent use. Its half-life is approximately 33 hours, which influences the frequency of administration to maintain stable levels in the body.
Source for this section: Sources for When should you take Melanotan II?: Jumps to this entry in the sources and references list at the end of the page.
Put it into practice
Reading about Melanotan II is the first step — DoseRoutine helps you act on it. These free tools turn what you just learned into a routine.
What interacts with Melanotan II?
| Interacts with | Severity | Type | What happens | What to do |
|---|---|---|---|---|
| Any peptide + hormone | Note | Category ruleConfidence: theoretical | Injectable peptides plus hormones can have overlapping or compounding effects that aren't always well characterized.Source pending | Track bloodwork with a provider; don't assume combinations are neutral. |
Frequently asked questions about Melanotan II
Melanotan II is a synthetic peptide that mimics alpha-melanocyte-stimulating hormone (α-MSH). It was developed to stimulate melanin production for tanning and has also been studied for its effects on sexual function and appetite.
No, Melanotan II is not approved by the U.S. Food and Drug Administration (FDA) for any human use. Its use is primarily limited to research or unregulated contexts.
Melanotan II is administered via injection.
Common side effects include nausea, flushing, dizziness, increased libido, spontaneous erections, appetite suppression, and skin darkening or changes in moles. Long-term safety data are limited.
There are concerns that Melanotan II could increase the risk of developing new moles or altering existing ones, potentially increasing the risk of melanoma, a serious form of skin cancer. However, definitive long-term studies confirming this risk are lacking.
Melanotan II is a peptide, and interactions are possible with prescriptions, hormones, peptides and other supplements in the same routine. Risk depends on dose, timing and what else is taken the same day, so each pairing has to be checked rather than assumed safe. The free checker at https://doseroutine.com/interaction-checker covers Melanotan II with no sign-up.
Melanotan II is administered by injection, so the measured volume — not a tablet count — is the unit that matters. Ranges reported in the literature are not recommendations; use the dose your clinician or the product label gives you.
Combining a peptide like Melanotan II with TRT is usually a question of labs rather than a blanket yes or no: the ester, injection interval and any aromatase inhibitor all change the answer. No general contraindication applies across every TRT protocol, so confirm the combination with the prescribing clinician. See the free TRT interaction reference: https://doseroutine.com/trt-supplement-interactions
Each peptide class carries its own profile against Melanotan II: a healing peptide raises different questions than a GLP-1 agonist or a growth-hormone secretagogue. Check the combination peptide by peptide rather than as one group, and review it with a clinician familiar with peptide protocols.
Published frequency for Melanotan II varies by protocol and formulation, so the label or prescription is what sets it. Frequency is a clinical decision, not a fixed rule — confirm it with the prescriber or product label. Comparison of apps that keep a schedule like this: https://doseroutine.com/best-dose-tracking-apps
The effect of a missed dose of Melanotan II depends on the protocol and formulation you are on. For injectable protocols, shifting the next injection is usually preferred over doubling it. Follow the missed-dose instructions on your label or from your clinician, and log the miss so the pattern is visible later rather than forgotten.
For an injectable like Melanotan II the record needs more than a checkbox: vial concentration, the measured volume, and which site the last injection went into. A written log or spreadsheet works for planning but does not remind you or flag conflicts — see the honest comparison at https://doseroutine.com/vs/spreadsheet and the wider roundup at https://doseroutine.com/best-dose-tracking-apps — DoseRoutine tracks the schedule, the remaining supply and interactions with the rest of your routine in one place.
Which studies looked at Melanotan II?
Peer-reviewed research indexed in PubMed. Each entry links to the original record.
- 1.Melanotan II: a possible cause of renal infarction: review of the literature and case report(opens PubMed in a new tab)CEN Case Rep · 2020 · PMID 31953620 · https://pubmed.ncbi.nlm.nih.gov/31953620/
- 2.Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical study(opens PubMed in a new tab)Life Sci · 1996 · PMID 8637402 · https://pubmed.ncbi.nlm.nih.gov/8637402/
Sources cited on this page
Specific documents referenced by the numbered markers above. Each number matches the marker in the text.
- PubChem CID 92432(opens in a new tab)National Center for Biotechnology Information · pubchem.ncbi.nlm.nih.gov/compound/92432
Verify at
Publisher search links for Melanotan II. These are places to check the information — they are not citations, so they are not numbered.
- DrugBank(publisher search, opens in a new tab)DrugBank Online · publisher search
- PubMed literature search(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed labeling archive(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Wikipedia entry(publisher search, opens in a new tab)Wikipedia · publisher search
DoseRoutine compiles summaries from publicly available scientific and regulatory references. Always verify important decisions with a licensed clinician. How we source and review this information.
What is the short answer on Melanotan II?
Plain-text summary, safe to quote verbatim:
Melanotan II (MT-II) is a synthetic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It was originally developed as a potential therapeutic agent for tanning as it stimulates melanogenesis (melanin production), leading to skin pigmentation. Research on Melanotan II focuses on libido and weight loss.
Source: DoseRoutine — https://doseroutine.com/library/melanotan-ii
Melanotan II cheat sheet
DoseRoutine cheat sheet · Peptide
Melanotan II
Melanotan II (MT-II) is a synthetic peptide analog of alpha-melanocyte-stimulating hormone (α-MSH). It was originally developed as a potential therapeutic agent for tanning as it stimulates melanogenesis (melanin production), leading to skin pigmentation.
Evidence
Limited
Human observational or case data only — no randomized trials.
Route
Self-administered subcutaneous injection is the route documented in reported user cases and toxicity reports
Research chemicalNot approved by the FDA or any medicines regulator; case reports document rhabdomyolysis and renal infarction after gray-market injectionLibidoWeight Loss
Studied ranges, not dosing advice. Not medical advice — talk to a clinician. doseroutine.com/library/melanotan-ii
Cite this page
Using this in an article, AI answer, or research note? Please attribute:
DoseRoutine. (2026). Melanotan II — Overview, Benefits & Side Effects. Retrieved from https://doseroutine.com/library/melanotan-ii
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