Peptides for Sunless Tanning: Risks & Reality

Tanning peptides are everywhere right now. TikTok influencers hold up nasal sprays and show dramatic before-and-after shots. Reddit threads swap dosing protocols. Online stores sell vials with vague labels and confident claims. The pitch is simple: inject or inhale a peptide, skip the UV damage, and get a deep tan without the sun.

The reality is more complicated -- and more dangerous -- than the marketing suggests. This guide covers what tanning peptides actually are, how they work, what the research shows about their safety, and what regulatory agencies worldwide have concluded about them.

What Are Tanning Peptides?
Melanotan I vs. Melanotan II: Key Differences
How Tanning Peptides Work
The Real Risks: What the Medical Literature Reports
Case Reports: Melanoma and Mole Changes
The Nasal Spray Problem
Regulatory Status Around the World
Afamelanotide (Scenesse): The Only Approved Version
Contamination and Product Quality
Safer Alternatives for a Tan
FAQ
The Bottom Line
References

What Are Tanning Peptides?

Tanning peptides are synthetic versions of alpha-melanocyte-stimulating hormone (alpha-MSH), a natural hormone that tells your skin cells to produce melanin -- the pigment responsible for skin color. Scientists at the University of Arizona developed the first tanning peptide analogs in the 1980s and 1990s as potential sunless tanning agents and skin cancer prevention tools [1].

Two main tanning peptides exist:

Melanotan I (afamelanotide) -- a linear peptide analog of alpha-MSH, now FDA-approved under the brand name Scenesse for a rare medical condition (not for cosmetic tanning)
Melanotan II -- a cyclic peptide analog that is shorter, more potent, less selective, and not approved by any regulatory agency for any use

When people talk about "tanning peptides" online, they are almost always referring to Melanotan II. It is the compound sold through unregulated online vendors, promoted by social media influencers, and increasingly available as nasal sprays, injections, and even gummies.

Melanotan I vs. Melanotan II: Key Differences

These two peptides share a name and a basic mechanism, but they are fundamentally different in their pharmacology and risk profiles.

Feature	Melanotan I (Afamelanotide)	Melanotan II
Structure	Linear, 13 amino acids	Cyclic, 7 amino acids
Receptor selectivity	Relatively selective for MC1R	Binds MC1R, MC3R, MC4R, MC5R
Primary effect	Melanin production	Melanin production + sexual arousal + appetite suppression
FDA status	Approved (Scenesse, for EPP only)	Not approved for any use
Administration	Subdermal implant (clinical setting)	Subcutaneous injection or nasal spray (self-administered)
Side effects	Injection site reactions, nausea, fatigue	Nausea, flushing, sexual effects, mole changes, potential melanoma link
Duration	Controlled release over ~2 months	Variable, user-dependent

The selectivity difference matters a lot. Melanotan I primarily activates the MC1R receptor, which controls melanin production. Melanotan II activates multiple melanocortin receptors throughout the body, which is why it causes side effects ranging from nausea and appetite loss to spontaneous erections and changes in sexual behavior [2].

How Tanning Peptides Work

Your skin color depends on melanin, a group of pigments produced by specialized cells called melanocytes. Here is the basic chain of events when you use a tanning peptide:

The peptide enters your bloodstream (through injection or nasal absorption).
It binds to melanocortin-1 receptors (MC1R) on melanocytes in your skin.
MC1R activation triggers melanogenesis -- the process of producing melanin.
Melanocytes package melanin into melanosomes, which are then distributed to surrounding skin cells (keratinocytes).
Your skin darkens as melanin accumulates in the upper layers.

With Melanotan II specifically, the non-selective receptor binding means the peptide also activates MC3R and MC4R in the brain, leading to appetite suppression, sexual arousal, and other central nervous system effects. Because Melanotan II can cross the blood-brain barrier, these effects can be pronounced [3].

One important distinction from natural tanning: UV exposure stimulates melanin production through DNA damage in skin cells, which triggers a protective melanin response. Tanning peptides bypass this signal entirely. They tell melanocytes to produce melanin regardless of UV exposure -- but the resulting tan does not provide the same level of UV protection that a natural, UV-induced tan does [4].

The Real Risks: What the Medical Literature Reports

The risk profile of Melanotan II draws from case reports, pharmacovigilance databases, user surveys, and small clinical observations. No large randomized controlled trials have been completed, which itself is a problem -- it means we are working with incomplete safety data.

Common Side Effects

The most frequently reported adverse effects include [2, 3]:

Nausea and vomiting (especially at higher doses)
Facial flushing
Headache
Loss of appetite
Fatigue and drowsiness
Yawning and stretching

These tend to be worst in the first few sessions and may decrease with continued use. However, "getting used to it" is not the same as "it is safe."

Serious Adverse Effects

The medical literature documents more serious outcomes:

Skin cancer concerns. Multiple case reports link Melanotan II use to melanoma, though establishing causation is complicated by the fact that many users also expose themselves to UV (sunbeds or sun) to "activate" the tan. The combination of melanocyte stimulation and UV exposure is precisely what dermatologists warn against [5].

Changes in moles. Melanotan II causes reversible darkening of existing moles and freckles, but it can also trigger the development of new moles and changes in mole structure. One case reported over 100 new melanocytic nevi appearing within weeks of starting Melanotan II, with several showing severe dysplasia on biopsy [6].

Rhabdomyolysis. A 39-year-old man who injected 6 mg of Melanotan II (roughly six times the commonly cited starting dose) was hospitalized in the ICU with systemic toxicity, rhabdomyolysis, and renal dysfunction. His creatine phosphokinase (CPK) reached 17,773 IU/L [7].

Kidney dysfunction. Case reports document renal complications following Melanotan II use [3].

Priapism. Painful, sustained erections lasting hours have been reported in male users, a direct consequence of MC4R activation in the brain. Priapism is a medical emergency that can cause permanent erectile dysfunction if untreated [3].

Uncontrolled melanin production. Unlike most peptides whose effects taper off when you stop using them, Melanotan II's effects on melanogenesis are not necessarily reversible. Once the peptide triggers melanin production, there is no reliable way to shut it down [8].

Case Reports: Melanoma and Mole Changes

The published dermatology literature contains several concerning case reports. While individual cases cannot prove causation, the pattern deserves attention.

Case 1: 20-year-old woman. After a 3-4 week course of Melanotan II injections combined with sunbed use, she developed a melanoma in her left gluteal region. She had Fitzpatrick skin type II (fair skin, burns easily) [5].

Case 2: Teenager with FAMMM syndrome. A young female with familial atypical multiple mole melanoma syndrome used Melanotan over 2 months while also attending UV tanning studios. Generalized skin darkening, darkening of multiple moles, and suspicious dermatoscopic changes occurred. One excised nevus was reported as dysplastic. After stopping Melanotan, pigmentation lightened considerably over 3 months [9].

Case 3: 25-year-old man. Within weeks of a 4-week course of Melanotan II, he developed over 100 new melanocytic nevi, mainly on his back. Ten of the most atypical lesions were removed. Three showed severe dysplasia. A pigmented basal cell carcinoma was also found on his shoulder [6].

Case 4: 22-year-old woman (2025). After using Melanotan II nasal spray, she developed a mass in the anterior maxilla. Histological analysis confirmed mucosal malignant melanoma. This is the first published case linking Melanotan II nasal spray to oral mucosal melanoma [10].

A 2017 review noted increasing numbers of case reports linking both Melanotan I and II to melanocytic changes, new dysplastic nevi, and melanomas emerging during or shortly after use [11].

The question researchers keep asking is whether Melanotan II caused these cancers or merely darkened pre-existing lesions enough to make them visible. The answer is not settled. But the fact that the question exists should give any prospective user serious pause.

The Nasal Spray Problem

Melanotan II nasal sprays exploded in popularity around 2022-2023, driven largely by TikTok. An analysis of tanning-related TikTok content found that 90% of videos promoted a positive view of tanning, with a growing subset specifically promoting Melanotan II nasal sprays and injections [12].

Why Nasal Sprays Are Particularly Risky

The nasal mucosa has no skin barrier. It is a thin membrane designed to warm and humidify air, not to block drug absorption. When Melanotan II is sprayed into the nose, it enters the bloodstream rapidly and unpredictably [12].

This creates dosing problems. With subcutaneous injections, users at least have some control over the amount entering their body (though self-dosing with unregulated products is inherently imprecise). With nasal sprays, absorption rates vary based on nasal congestion, spray technique, and product concentration. Users have no reliable way to know how much active peptide they are actually absorbing.

Marketing to Young People

The marketing of tanning nasal sprays specifically targets young consumers. Products are sold in flavored varieties -- peach, bubblegum, Red Bull, grape -- with packaging and branding designed to look like wellness products rather than unapproved drugs [13]. TikTok has banned hashtags including #nasaltanningspray, #melanotan, and #melanotan2, but sellers adjust their marketing to avoid detection [12].

One user was hospitalized after a severe reaction to a nasal tanning spray purchased online, reporting that she was "unable to breathe" [13]. This is not an isolated incident -- it is what happens when unregulated drugs are marketed as cosmetic products.

Regulatory Status Around the World

No regulatory agency anywhere in the world has approved Melanotan II for any use. The consensus is global and unambiguous.

Country/Region	Status
United States	Not FDA-approved. Illegal to sell for human consumption. FDA has issued warning letters to sellers [14].
United Kingdom	Banned since 2019. Sale, supply, and possession are illegal [3].
Australia	Not approved by TGA. Sale as a tanning agent is prohibited. TGA has issued public warnings [4].
European Union	Not approved by EMA. Individual member states have issued warnings [3].
Canada	Not approved by Health Canada for any indication [3].

The FDA reiterated in 2024 that Melanotan products marketed for human use are unapproved new drugs and misbranded cosmetics [14]. Despite this, online sales continue through websites, social media, and gym/beauty salon distribution networks.

Afamelanotide (Scenesse): The Only Approved Version

It is worth understanding afamelanotide because it represents what tanning peptide research looks like when done properly -- through clinical trials, regulatory review, and medical oversight.

What It Is

Afamelanotide is a synthetic 13-amino-acid analog of alpha-MSH. It differs from the natural hormone by just two amino acids, which give it greater receptor affinity and a longer half-life. It is the molecule that was originally called Melanotan I before being developed into a regulated pharmaceutical [15].

FDA Approval

The FDA approved afamelanotide (brand name Scenesse) on October 8, 2019, for one specific indication: increasing pain-free light exposure in adults with erythropoietic protoporphyria (EPP). EPP is a rare inherited disorder in which a deficiency of the enzyme ferrochelatase causes protoporphyrin IX to accumulate in the skin, resulting in extreme photosensitivity and intense pain upon sun exposure [15].

Approval was based on three trials involving 244 adults across 22 sites in the US and Europe, which measured pain-free hours in sunlight, outdoor activity levels, and side effects [15].

How It Differs from Underground Melanotan

Feature	Afamelanotide (Scenesse)	Underground Melanotan II
Regulatory status	FDA/EMA approved	Not approved anywhere
Manufacturing	GMP-regulated facility	Unknown origin, unregulated
Purity	Tested and verified	Variable, potentially contaminated
Administration	Subdermal implant by specialist physician	Self-injection or nasal spray
Dosing	Standardized (16 mg implant)	Uncontrolled
Indication	EPP (medical condition)	Cosmetic tanning
Monitoring	Under medical supervision	None
Side effects	Documented through clinical trials	Incompletely characterized

The gap between these two products illustrates why the regulatory process exists. Afamelanotide went through years of clinical testing to establish safety and efficacy for a specific medical condition. Melanotan II has never completed that process for any indication.

Contamination and Product Quality

When you buy Melanotan II from an online vendor, you are purchasing an unregulated product from an unverified source. The practical implications of this are significant.

A 2014 analysis of commercially available Melanotan II products from multiple online vendors found impurity levels ranging from 4.1% to 5.9%, with the actual amount of Melanotan II varying significantly from what was advertised [16]. That means the vial might contain less active peptide than claimed, more than claimed, or unknown contaminants that were never tested for safety.

Other contamination risks include:

Bacterial or endotoxin contamination from non-sterile manufacturing
Degradation products from improper storage or shipping
Cross-contamination with other peptides or chemicals processed in the same facility
Mislabeling -- what is in the vial may not match the label at all

For injectable products, contamination can cause infections ranging from localized abscesses to systemic sepsis. For nasal sprays, contamination can cause respiratory inflammation and allergic reactions [16].

Safer Alternatives for a Tan

If you want darker skin without UV exposure, evidence-based options exist that do not involve unapproved systemic drugs.

Dihydroxyacetone (DHA) Self-Tanners

DHA is the active ingredient in most topical self-tanners. It is a simple sugar that reacts with amino acids in the dead cells of your skin's outermost layer (stratum corneum), producing brown pigments called melanoidins. This is a surface-level chemical reaction -- DHA does not enter your bloodstream, does not affect melanocytes, and does not stimulate melanin production [17].

DHA-based self-tanners are FDA-approved for external application. The color develops over 2-4 hours and fades gradually over 5-7 days as dead skin cells naturally slough off.

Important: DHA self-tanners do not provide UV protection. You still need sunscreen.

Professional Spray Tans

Professional spray tans use DHA in a fine mist applied evenly across the body. They typically produce a more uniform result than at-home products and last about the same duration (5-7 days).

Bronzing Makeup and Powders

Temporary bronzing products wash off at the end of the day. They carry no systemic risk and allow complete control over application and intensity.

What Doesn't Work

"Tanning drops" and "tanning gummies" containing Melanotan II or similar compounds are simply alternative delivery methods for the same unapproved drug. The route of administration does not change the risk profile of the active ingredient.

FAQ

Do tanning peptides actually work? Melanotan II does increase melanin production, and users do get darker skin. The question is not whether it works -- it is whether the tanning effect is worth the documented and unknown risks of using an unregulated, unapproved drug.

Can you get tanning peptides legally? In most countries, it is illegal to sell Melanotan II for human use. Afamelanotide (Scenesse) is legally available by prescription for EPP patients only. Purchasing Melanotan II online may technically be legal in some jurisdictions for "research purposes," but using it on yourself means using an unapproved drug without medical supervision.

Do tanning peptides protect against sunburn? No. The tan produced by Melanotan II does not provide the same UV protection as a natural, UV-induced tan. The Australian Therapeutic Goods Administration specifically states that "use of melanotan to increase skin pigmentation artificially will not protect against UV exposure the way a suitable sunscreen will" [4].

Are nasal tanning sprays safer than injections? No. They contain the same active ingredient (Melanotan II) with the same systemic risks. The nasal route actually introduces additional concerns: unpredictable absorption, respiratory irritation, and even less dosing control than subcutaneous injection.

What should I do if I've already used Melanotan II? Stop using it and see a dermatologist. Ask for a full-body skin examination with dermatoscopy to check for any changes in existing moles or new suspicious lesions. Be honest with your doctor about what you used -- they need to know for accurate clinical assessment [4].

Can Melanotan II cause permanent changes? Yes. Some mole changes and skin pigmentation changes may not fully reverse after stopping the peptide. In one case study, pigmentation lightened considerably after 3 months but did not return to baseline [9]. New moles triggered by Melanotan II may persist permanently.

Is Melanotan I (afamelanotide) safer than Melanotan II? Afamelanotide has gone through clinical trials and regulatory review, which means its safety profile is better characterized. It is more selective for MC1R, which means fewer off-target effects. However, it is only approved for a specific medical condition (EPP), not for cosmetic tanning, and is administered by healthcare professionals in a controlled setting [15].

The Bottom Line

Tanning peptides work. That has never been the question. The question is whether a cosmetic tan justifies the use of an unapproved, unregulated drug with documented links to melanoma, rhabdomyolysis, kidney dysfunction, and dozens of other adverse effects.

Every major health authority in the world -- the FDA, the UK MHRA, the Australian TGA, Health Canada, the EMA -- has reached the same conclusion: Melanotan II should not be used for cosmetic tanning. This is not a marginal disagreement or a gray area. The regulatory consensus is clear.

The social media marketing of tanning peptides -- especially nasal sprays targeted at young people -- is one of the more concerning public health trends in dermatology right now. Products sold in flavored spray bottles, promoted by influencers with no medical training, and manufactured in facilities with no regulatory oversight are not wellness products. They are unregulated drugs being marketed as cosmetics.

If you want darker skin without UV exposure, DHA-based self-tanners are the evidence-based choice. They are cheap, widely available, FDA-approved for external use, and carry no systemic risk. They will not give you the "real" tan that Melanotan II produces -- but they also will not put you in a dermatologist's office explaining why you have 100 new moles.

For more on the science behind these peptides, see our detailed profiles of Melanotan II and Melanotan I. For broader context on skin-related peptide research, check out our guide to peptides for skin anti-aging.

References

Hadley ME, Dorr RT. Melanocortin peptide therapeutics: historical milestones, clinical studies and commercialization. Peptides. 2006;27(4):921-930.
DermNet NZ. Melanotan II. 2024. Link
Nelson ME, et al. An unhealthy glow? A review of melanotan use and associated clinical outcomes. J Subst Use. 2015;20(4):288-294. Link
Australian Therapeutic Goods Administration. Don't risk using tanning products containing melanotan. 2023. Link
Hjuler KF, Lorentzen HF. Melanoma associated with the use of melanotan-II. Dermatology. 2014;228(1):34-36. PMID: 24355990
Hueso-Gabriel L, et al. Eruptive dysplastic nevi following melanotan use. Actas Dermosifiliogr. 2013;104(2):173-175. Link
Devlin J, et al. Melanotan II injection resulting in systemic toxicity and rhabdomyolysis. Pigment Cell Melanoma Res. 2012;25(6):879-881. PMID: 23121206
Hudson Medical. The Barbie peptide can help you tan, but is it safe? 2024. Link
Sivyer GW. Changes of melanocytic lesions induced by melanotan injections and sun bed use in a teenage patient with FAMMM syndrome. Australas J Dermatol. 2012;53(4):e65-e67. PMC3663356
Sherring D, et al. Melanotan II nasal spray: a possible risk factor for oral mucosal malignant melanoma? Br J Oral Maxillofac Surg. 2025. PMID: 40210573
Brennan R, et al. Risks of unregulated use of alpha-melanocyte-stimulating hormone analogues: a review. Br J Dermatol. 2017;176(3):569-577. PMID: 28266027
Kream LE, et al. Nasal tanning sprays: illuminating the risks of a popular TikTok trend. Cutis. 2024. Link
Trading Standards UK. Nasal tanning sprays linked with skin cancer and serious respiratory problems. 2025. Link
U.S. Food and Drug Administration. Warning letters related to melanotan products. 2024.
Wikipedia contributors. Afamelanotide. Wikipedia. Link; FDA approval: Link
van Hout MC, et al. Melanotan II user experience: a qualitative study of online discussion forums. Perform Enhanc Health. 2021;9(3-4):100207. PMID: 34464955
Cleveland Clinic. Why you should never use nasal tanning spray. 2024. Link

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