Where to Buy Melanotan II: 7 Purity and Identity Checks, and Why a High Purity Score Is Not Reassurance

Melanotan II is approved in no country, and its documented harms came from correctly identified product. Mass spectrometry confirmed the injected substance in one rhabdomyolysis case. A purity certificate therefore answers less on this compound than on any other.

That is an uncomfortable thing for a buying page to open with, and it is the finding. Melanotan II sits in the libido and sexual wellness peptides category, and the full evidence picture — a two-decade international case literature, five national regulators on record and no completed efficacy trial for tanning — is in melanotan II: the evidence is present, and it points the wrong way. For converting a reconstituted vial into an injection volume there is the peptide dosing calculator.

What is melanotan II, and why does source quality matter?

Melanotan II is a cyclic heptapeptide analogue of α-MSH — Ac-Nle⁴-c[Asp⁵-His⁶-D-Phe⁷-Arg⁸-Trp⁹-Lys¹⁰]-NH₂, CAS 121062-08-6, 1,024.18 g/mol — and a non-selective melanocortin agonist. Source quality matters differently here: the compound sits one terminal group from PT-141 at 1,025.2, and the harms in the case literature came from correctly identified melanotan II, so a certificate can resolve the identity question and none of the safety one. It activates MC1R, MC3R, MC4R and MC5R at once.

The molecule is built from the α-MSH message core, with norleucine at position 4, D-phenylalanine at position 7, and an Asp5→Lys10 lactam bridge closing the ring.

Non-selectivity is what makes the harm list coherent. Priapism is not an idiosyncratic reaction to a tanning drug; it is MC4R activation. Nausea is the same. The case literature reads like a scattered collection of unrelated events only if you assume the compound is a pigmentation agent. It is not — it is a melanocortin agonist with no receptor selectivity, and the pigmentation is one of four things it does at once. There is no dose that produces one effect without risking the others, which means no sourcing decision improves that trade-off.

Vendor coverage and identity references sit on the melanotan II compound page.

What is the regulatory status of melanotan II?

Melanotan II is approved in no country, and five national regulators have said so on the record. Ireland's HPRA stated on 10 August 2023 that it is "not authorised by the HPRA or any medicines regulator to treat any condition"; Australia's TGA issued 27 infringement notices totalling $101,412 in May 2026. As of August 2026 it cannot be legally compounded in the United States, and WADA's S0 catch-all prohibits it at all times.

Ireland — HPRA, 10 August 2023. The notice names the risks as "development of new moles, darkening of existing moles and freckles, potential loss of vision, muscle tremors, stroke and anaphylaxis," advises users to "stop immediately," and records that the agency removed more than 500 social media and e-commerce listings between July 2022 and June 2023.

Australia — TGA, 21 May 2026. Twenty-seven infringement notices totalling $101,412 were issued to a New South Wales individual for alleged unlawful supply, with the statement that "there are currently no products containing Melanotan II on the Australian Register of Therapeutic Goods or approved for supply in Australia."

United Kingdom — MHRA, FOI response 24/274, 17 April 2024. "Products containing Melanotan II are classified as medicines if they are injectable or pens," and "the sale, supply and advertising of unauthorised medicines is not permitted." The agency received 16 UK Yellow Card adverse drug reaction reports between 2012 and 2022 and has "repeatedly taken action to remove Melanotan products from the market for over 10 years."

Denmark — Lægemiddelstyrelsen, 20 June 2011, restating a 2008 alert, warns against the product "because the effect is not documented, and because studies of possible side effects are lacking."

United States — FDA, Notice of Opportunity for Hearing, 5 August 2016. Melanotan II "constituted a new drug under the FDCA that could not be introduced or delivered for introduction into interstate commerce without an FDA approved application." The action followed a seller who continued shipping after an August 2007 warning letter, made therapeutic claims about reducing skin cancer risk and curing rosacea, and falsely advertised the product as "100% U.S. made" while importing from China.

On FDA's compounding page, current 22 April 2026, melanotan II is not among the fourteen substances in the active Category 2 group. It sits in a separate table headed "Bulk drug substances nominated but withdrawn," which is a procedural event — the nominator withdrew — and not a safety clearance. FDA's evaluation language is retained on that page and is stronger than the placement: compounded drugs containing melanotan II "may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation or peptide-related impurities," and "published case reports discuss serious adverse events including melanoma, posterior reversible encephalopathy syndrome, sympathomimetic toxidrome and priapism."

There is no compounding route for melanotan II at all: it is not on the 503A bulks list, has no USP monograph and is not a component of any approved drug, so it satisfies none of the three statutory routes and cannot be legally compounded. It remains an unapproved new drug. See our FDA peptide regulation timeline and are peptides legal — regulatory status by country.

How do you tell melanotan II from PT-141, and why does the answer settle less than it should?

High-resolution mass spectrometry or MS/MS fragmentation distinguishes melanotan II at 1,024.18 Da from bremelanotide at 1,025.2, a gap of about 1 dalton on 1,024 that HPLC and nominal-mass MS cannot resolve. On this compound the identity check settles less than usual. Someone ordering melanotan II is not defrauded if the vial is correct, and the published harms came from correctly identified material — mass spectrometry confirmed the injected substance in the rhabdomyolysis case.

That case is worth stating in full, because it is the argument. A 39-year-old man injected 6 mg subcutaneously, six times the recommended starting dose. Within two hours he had body aches, sweating, anxiety and mydriasis. His creatine phosphokinase peaked at 17,773 IU/L and he spent three days in intensive care. Mass spectrometry confirmed the injected substance was melanotan II. This was not a contaminated or mislabelled product. The molecule did it, at a dose the user chose because dosing guidance for an unapproved drug does not exist.

This is the one compound on this platform where a high purity score should provide no reassurance at all, because the molecule is the problem. Every other article in this cluster ends with a verification procedure that meaningfully reduces the buyer's risk. Here the procedure confirms you received what you ordered, and what you ordered has a two-decade international case record: melanoma and melanoma in situ, oral mucosal melanoma after nasal spray use, five simultaneous primary melanomas in situ in one patient, more than 100 eruptive naevi after four weeks with severe dysplasia in three of ten excised, priapism, renal infarction and posterior reversible encephalopathy syndrome.

Two published analytical studies exist on exactly this discrimination. Mestria et al. (Drug Testing and Analysis, 2021) characterised black-market melanotan II and bremelanotide by LC-HRMS, and Breindahl et al. (Drug Testing and Analysis, 2015) identified and characterised melanotan II products sold illegally online. Their existence tells you the market has an identity problem serious enough for forensic chemists to study. See mass spectrometry for peptides for what resolution buys, and melanotan 1 versus melanotan 2 for the analogue that is a different molecule again.

On what the case literature is and is not. These are case reports. They establish that these events happened in people using melanotan II; they cannot establish incidence, and melanoma has a long latency with sun exposure and tanning-bed use as confounders in most of these patients. There is no systematic review of melanotan II adverse effects in existence, and nobody should claim one in either direction. What can be said is that the signal is consistent across multiple countries and two decades, and that FDA independently reached the same list.

7 things to check before ordering melanotan II

Seven checks cover melanotan II, and they establish what is in the vial rather than whether it is safe to inject. High-resolution mass spectrometry at 1,024.18 Da, third-party HPLC from a named laboratory against a 99.62% benchmark, net peptide content, fill accuracy against a recorded range of −7.3% to +16%, an LAL endotoxin result that is mostly absent here, the claims on the listing itself, and a pricing check read inside a single vial-size band.

1. High-resolution MS or MS/MS fragmentation at 1,024.18 Da. This confirms melanotan II rather than bremelanotide at 1,025.2. Nominal-mass MS cannot separate the two and HPLC co-elutes them, so ask for the instrument type and a batch-matched result rather than a specimen certificate from an earlier lot, which describes a different vial.

2. Third-party HPLC purity from a named laboratory — and what it does not establish. This platform records 99.62% across 251 independent tests, so "above 98%" describes a standard the market already clears. HPLC measures homogeneity, not identity and not safety (what HPLC testing measures), and a vendor's own document is not third-party testing (third-party peptide testing labs).

3. Net peptide content. Purity reports the proportion of a sample that is one species; net content reports how much peptide is in the vial, with acetate salt and residual water sitting inside the difference. Ask for a net content or amino acid analysis figure separately (why 10 mg isn't 10 mg).

4. Fill accuracy, against a recorded −7.3% to +16%. That is the quantity variance in this platform's melanotan II data, and it matters more than usual on a compound with no established dose: the reader has no label to titrate against, so a 16% overage compounds an already unguided decision. Quantitative content testing is the check.

5. An LAL endotoxin result. Endotoxin results are mostly absent on melanotan II. A blank field means the batch was not tested for pyrogens rather than that it passed, and FDA's own evaluation language flags immunogenicity risk "due to the potential for aggregation or peptide-related impurities" (peptide endotoxin testing and the LAL assay).

6. The listing itself, read against what regulators have already prosecuted. A vendor claiming melanotan II reduces skin cancer risk or treats rosacea is making the exact therapeutic claims in FDA's 2016 Notice of Opportunity for Hearing, and an origin claim like "100% U.S. made" was false in that case while the product was imported from China. Nasal-spray presentations are not a safer route — the oral mucosal melanoma case followed nasal spray use — and MHRA classifies injectables and pens as medicines, which makes their sale unlawful in the UK. See how to spot a scam peptide shop.

7. The pricing check, read within a vial-size band — and what no certificate establishes. Listings run from $1.50/mg on a 10 mg vial to $9.00/mg, so a per-milligram comparison across sizes is not like-for-like. Beyond that, a flawless certificate confirms a cyclic heptapeptide at a stated quantity. It does not touch FDA's four named harms, the melanoma and eruptive naevi case series, or the fact that no completed randomised trial supports the use you are buying it for. See red flags in peptide certificates of analysis.

Where does melanotan II rank on Peptigrity's lab test database?

Peptigrity's Purity Index records melanotan II at 99.62% across 251 independent tests from ILS, MZ Biolabs, Kovera, Janoshik and Freedom Diagnostics, across 226 verified shops (verified August 2026). Price data shows 69 shops in stock at a median of $3.80 per milligram, lowest $1.50/mg on a 10 mg vial and highest $9.00/mg, from 173 known shops (verified 10 August 2026). Quantity variance runs −7.3% to +16% and endotoxin results are mostly absent.

Those figures exclude shipping, taxes and customs, coupon codes, bulk tiers, multi-vial kits and account-gated pricing.

Naming the five laboratories matters, because a reader can then weigh where 251 tests came from rather than take a bare percentage, and can search the lab test database and community-verified shop reviews for a specific vendor. Peptigrity tracks 530 shops and 11,852 independent lab tests across 118 peptides, with 1,283 community reviews (verified August 2026), weighting community reviews and independently verified HPLC purity equally at 50% each, with no financial relationships influencing the ranking — the methodology is documented at how we calculate trust scores.

And having reported that number, we will not let it do work it cannot do. The volume of testing on this compound is not the problem. A 99.62% average across 251 tests establishes that vendors are shipping homogeneous melanotan II, which is exactly the material in the case reports. On every other compound in this cluster the platform's purity data is the buyer's best tool. Here it is a measurement of how reliably the market delivers a substance five regulators have acted against.

The trial that would settle this would have to be randomised, controlled and prospective, because the entire safety literature is case reports.

There is no sponsor for a cosmetic indication in a compound already prosecuted as an unapproved new drug in multiple jurisdictions. That absence is permanent rather than a temporary gap better evidence will close, and it belongs in a buying decision as a fixed condition.

Frequently Asked Questions

What purity standard should melanotan II meet?

This platform records melanotan II at 99.62% across 251 independent tests from ILS, MZ Biolabs, Kovera, Janoshik and Freedom Diagnostics, across 226 verified shops (verified August 2026). Against a market clearing that high, "above 98%" promises less than the norm. The more important point is that purity is the wrong axis here: the published harms occurred with correctly identified, homogeneous melanotan II, so a strong purity figure is not a safety finding.

How much does melanotan II cost?

Price data shows 69 shops in stock at a median of $3.80 per milligram, with the lowest tracked listing at $1.50/mg on a 10 mg vial and the highest at $9.00/mg, from 173 known shops (verified 10 August 2026). Vial size drives much of that spread, so compare within a band rather than across. Those figures exclude shipping, taxes and customs, coupon codes, bulk tiers, multi-vial kits and account-gated pricing.

Is melanotan II legal?

It is approved in no country. Regulators in Ireland, the UK, Australia, Denmark and the United States have all stated it is unauthorised, and several have taken enforcement action — Australia's TGA issued 27 infringement notices totalling $101,412 in May 2026. In the United States it is an unapproved new drug with no compounding route, and WADA's S0 catch-all prohibits it in sport at all times.

How do I know the vial contains melanotan II and not PT-141?

High-resolution mass spectrometry or MS/MS fragmentation on your batch, confirming 1,024.18 Da rather than 1,025.2. The two share an identical backbone and lactam bridge and differ only at the C-terminus — an amide against an acid, about 1 dalton on 1,024. HPLC co-elutes them and nominal-mass MS is unreliable. Note the direction of the risk: receiving bremelanotide instead is not the substitution that harms a melanotan II buyer.

What dose of melanotan II has been established?

None. No completed randomised controlled trial for tanning exists, the only registry record is a recruiting phase 2 vitiligo study with no results, and the human material behind the compound is a 1990s pilot phase 1 study and a small erectile-function study. The rhabdomyolysis patient injected 6 mg subcutaneously, described in the case report as six times the recommended starting dose, and reached a CPK of 17,773 IU/L. There is no label to titrate against, which is a fact about the compound rather than about the vendor.

Does melanotan II cause melanoma?

Multiple case reports document melanoma and melanoma in situ in users, including oral mucosal melanoma after nasal spray use and five simultaneous primary melanomas in situ in one patient. Case reports cannot establish incidence, and tanning-bed use and sun exposure confound most of them. Better documented is eruptive and dysplastic naevi: one patient developed more than 100 new moles after four weeks, with severe dysplasia in three of ten excised.

Browse the libido and sexual wellness peptides category, or our complete peptide guide with 118 compounds (verified August 2026). For per-injection volume, use the peptide dosing calculator alongside the reconstitution calculator. Compare shops through independent lab tests and community-verified shop reviews.

This article is for educational and informational purposes only and does not constitute medical advice. Peptides discussed may be investigational compounds not approved by the FDA (or equivalent regulators in your jurisdiction) for human use. Always consult a qualified healthcare provider before using any peptide or research compound. Peptigrity is an independent review platform and does not sell, endorse, or recommend specific products or vendors.