Nasal tanning sprays: what a dermatologist's warning actually means

What did @joshzeichnermd actually say?

He said nasal tanning sprays are trending, urged viewers not to use them, and identified the active ingredient as a peptide that mimics a naturally occurring hormone. His core concern was simple: "we just don't know if they're safe." He flagged three specific risks: appetite changes, effects on sex drive, and the theoretical possibility of cancerous skin changes. He closed by recommending self-tanning creams as the only safe alternative.

This is a measured, cautious take from a board-certified dermatologist, and for the most part it holds up. He did not oversell the danger or manufacture certainty where none exists. But there are a few places where the framing deserves closer inspection, particularly around the cancer claim and what "mimics a hormone" actually means biologically.

Does the science back this up?

Mostly, yes. The peptide in question is almost certainly melanotan II (MT-II), a synthetic analog of alpha-melanocyte-stimulating hormone (alpha-MSH), which binds melanocortin receptors (MC1R through MC5R) and drives melanogenesis. The off-label, unregulated nature of these products is a legitimate clinical concern backed by published literature.

The appetite and libido effects are real and documented. MC4R activation by MT-II suppresses appetite, while MC3R and MC4R signaling influences sexual arousal. A randomized controlled trial by Diamond et al. (2004, Annals of Internal Medicine) found that intracavernosal MT-II produced erections in men with psychogenic erectile dysfunction, confirming central receptor activity beyond just skin. Nausea, flushing, and spontaneous erections were the most commonly reported adverse effects in that study.

The cancer angle is where things get more speculative. Melanocyte stimulation does not directly cause melanoma. However, case reports have documented new or changing nevi following MT-II use, and a letter by Langan et al. (2011, British Journal of Dermatology) described a case of melanoma in a MT-II user. That is not proof of causation, but it is a legitimate signal worth naming.

What did they get wrong (or right)?

He got the core risk profile right. But the phrase "theoretically lead to cancerous changes" is doing a lot of work without enough scaffolding. Viewers may hear that as "this causes skin cancer," which the current evidence does not support. The honest read of the literature is that MT-II may accelerate growth in pre-existing atypical nevi rather than de novo cause malignancy. That distinction matters.

He also described MT-II as a peptide that "mimics a hormone naturally found in our bodies," which is accurate but incomplete. Alpha-MSH is naturally produced and breaks down quickly. MT-II is a modified, cyclic version engineered specifically to resist degradation and bind more aggressively. That is why it produces systemic effects at low doses. The word "mimic" understates the pharmacological difference.

What he got right: framing this as an unregulated, understudied compound with systemic receptor activity beyond skin. That is exactly the right warning to give a general audience on TikTok.

What should you actually know?

Melanotan II is not FDA-approved for any indication. It is not legally sold as a drug or cosmetic in the United States. Products sold as "tanning nasal sprays" are unregulated, meaning there is no quality control, no verified dosing, and no post-market safety surveillance. You genuinely do not know what you are putting in your body.

The systemic receptor profile is the real issue here. MT-II does not just hit your skin cells. It crosses into central nervous system activity, affecting appetite regulation, sexual function, and potentially cardiovascular tone. A review by Wikberg et al. (2000, Drug Discovery Today) mapped the full melanocortin receptor system and made clear that a compound hitting all five receptor subtypes is not a benign cosmetic agent.

If you are interested in peptide therapy for legitimate clinical indications, that conversation belongs with a licensed provider, not a nasal spray purchased from an unverified online vendor. Self-tanning creams using dihydroxyacetone (DHA) remain the only topically applied option with an actual safety record.