The answer so far

Melanotan II is sold as a tanning peptide, but an online injection is not a regulated sunscreen or a proven cosmetic treatment. The useful questions are product identity, human evidence, harms and ultraviolet protection.

Melanotan II is a synthetic analogue of melanocortin hormones marketed online for tanning and sometimes sexual-function claims. It is not the same as a regulated sunscreen or a validated cosmetic product. Unapproved injectable products can have uncertain identity, contents and safety, and darker skin is not a substitute for UV protection.34

On this page
  1. Tanning is not skin protection
  2. What have small human studies found?
  3. Why online vials are difficult to assess
  4. What can a product test tell us?
  5. Keep claims separate
  6. Sources

Tanning is not skin protection

Melanocortin signalling can affect pigmentation, but a darker skin tone from a product does not mean that ultraviolet damage is prevented. Sunscreen, protective clothing and shade address exposure; an unapproved tanning peptide does not replace them.

For the difference between pigment, self-tanner, sunscreen and related medicines, see the practical tanning comparison.43

What have small human studies found?

A 1996 pilot gave injected Melanotan II or saline on alternating days to three male volunteers. Two developed increased pigmentation; nausea was reported, and one participant experienced marked sleepiness and fatigue at the highest tested level. A separate 1998 crossover study in ten men with erectile difficulties of no known organic cause reported a longer average duration of measured penile rigidity after Melanotan II than placebo, alongside more nausea and other transient effects. These small, short studies show biological effects, not an established safe tanning product or a validated treatment for sexual difficulties. They cannot establish long-term or rare risks.

For the separate question of desire and erections, see Melanotan II, libido and PT-141.78

Why online vials are difficult to assess

Products sold outside an authorised supply chain may have uncertain identity, concentration, sterility, storage and contaminants. A label or user review cannot establish those properties or show that an injected product is safe.34

The US FDA says compounded drugs containing Melanotan II may pose a risk of an immune response for certain routes because of possible aggregation or peptide impurities. It also cites published case reports of serious events, including melanoma and prolonged erection (priapism). Case reports cannot establish how often these events occur or prove that the peptide caused each one.2

Australia’s TGA also reports increased moles and freckles, kidney dysfunction and brain swelling in association with Melanotan II. These reports do not establish how often events occur or prove that the product caused each event. The regulator advises anyone who has recently used an unapproved melanotan tanning product to stop and speak with a health professional.15

Seek emergency care for an erection lasting more than 3 to 4 hours. If you have sickle cell disease, seek emergency care for a painful erection lasting more than 1 hour. Prolonged erections need urgent treatment to reduce the risk of permanent damage.6

What can a product test tell us?

In an August 2026 Australian safety alert, the Therapeutic Goods Administration reported testing five seized nasal spray bottles from one labelled product. The estimated Melanotan II amount varied from 22 to 54 mg per bottle, based on the labelled bottle volume; the label stated 30 mg. This is evidence about those samples, not a measurement of every product or spray. It illustrates why a seller’s label cannot establish a product’s contents or safety. The regulator advises people using melanotan tanning products to stop and consult a health professional about concerns.9

Keep claims separate

Pigmentation, sexual-function claims and possible adverse effects are different questions requiring different evidence. This page does not recommend use, dosing or sourcing and does not treat a product claim as a clinical finding. Explore how trials compare treatments, why medicines have side effects. FDA also plans a separate advisory discussion of melanotan II before the end of February 2027; an agenda does not determine the outcome. Understand the US policy and planned meeting.10

Development & regulatory context

These selected records are not a complete global legal-status list. Approval depends on the product, use, population and country; check each record’s date.

Australia / CanadaChecked 3 Nov 2026

Products marketed as Melanotan II

Unapproved products subject to regulator warnings
Tanning and wellness claims

Health authorities warn about unapproved peptide products sold online, including melanotan products. Product warnings are not a substitute for a current national authorisation database.4

Further reading

Trusted external resources selected to help explain this page. They open in a new tab.

Sources, kept close.

Selected supporting sources; this is not a complete literature review.

  1. Don’t risk using tanning products containing melanotanTherapeutic Goods Administration, Australia · Regulator safety communicationAccess checked 2026-11-07 · Reports described by the regulator do not establish incidence or the risk of every product.
  2. Certain bulk drug substances for compounding that may present significant safety risksU.S. Food and Drug Administration · Regulator safety assessmentAccessed 2026-11-03
  3. Concerns regarding the public health risks associated with unapproved peptide productsTherapeutic Goods Administration · Regulator safety communicationAccessed 2026-11-03
  4. Peptides: overview and safety informationHealth Canada · Government health informationAccessed 2026-11-03
  5. Melanotan II tanning peptide products found to be inconsistently dosedTherapeutic Goods Administration · Regulator safety advisoryAccessed 2026-11-03
  6. Priapism (painful erections)NHS · UK urgent health guidanceAccess checked 2026-11-07 · Advises emergency care for an erection lasting more than 3 to 4 hours, or a painful erection lasting more than 1 hour with sickle cell disease.
  7. Evaluation of melanotan-II, a superpotent cyclic melanotropic peptide in a pilot phase-I clinical studyLife Sciences / PubMed · Small placebo-controlled phase I human pilot; United States; 1996Accessed 2026-11-04
  8. Synthetic melanotropic peptide initiates erections in men with psychogenic erectile dysfunction: double-blind, placebo controlled crossover studyJournal of Urology / PubMed · Small double-blind placebo-controlled crossover study; United States; 1998Access checked 2026-11-05 · Ten men, placebo-controlled crossover, short monitoring; abstract and published contemporaneous commentary reviewed, not the full original paper.
  9. Melanotan II tanning peptide products found to be inconsistently dosedTherapeutic Goods Administration · Official product safety alert and laboratory testing; Australia; 17 August 2026Accessed 2026-11-04
  10. Meeting of the Pharmacy Compounding Advisory CommitteeUS Food and Drug Administration · Future advisory meeting noticeAccessed 2026-11-06