Astaxanthin to help tanning and provide a bronzed complexion?

The astaxanthin has been mentioned as an active ingredient in the tanning process, stimulating melanin production. This idea may arise from the pigment’s red colour. Astaxanthin gives certain marine animals, such as shrimp, crabs, and salmon, their pink hue. But can it enhance tanning in humans? For clarity, melanin is a black or brown pigment produced during the melanogenesis, the process by which melanin forms in melanosomes. For astaxanthin to enhance tanning, it would need to activate melanogenesis. However, evidence does not support this.

Studies in vitro have shown that astaxanthin reduces tyrosinase activity, a key enzyme in melanin synthesis. This mechanism involves inhibition of DOPA and dopaquinone auto-oxidation, two immediate melanin precursors. In a study on B16 murine melanoma cells, this inhibition led to a reduction of 40% in melanin content, without harming cell viability.

These observations were confirmed in a human epidermal equivalent model. When these tissues were stimulated for 14 days with a stem cell growth factor (5 nM), pigmentation increased over time. This correlated with increased expression of melanocyte-specific genes and proteins, including TYR, TYRP1, Pmel17, and MITF. The addition of astaxanthin (1 to 8 µM) suppressed this growth factor–induced pigmentation in a dose-dependent manner, without altering tissue structure. At 8 µM, inhibition was near total. Subsequent transcriptomic and proteomic analyses showed that astaxanthin repressed the expression of melanogenesis markers through the interruption of intracellular signals associated with the growth factor. This suggests that the pigment acts upstream to regulate melanogenesis.

It appears that astaxanthin cannot facilitate tanning.

However, astaxanthin protects the skin from free radicals generated during sun exposure. It has potent antioxidant properties from its specific chemical structure. The 13 conjugated double bonds and polar groups at the ends of the astaxanthin molecule enable efficient electron capture and insertion into membrane lipid bilayers, acting as a cellular shield. In addition, studies in vitro have shown its ability to inhibit prostaglandin E2 release by HaCaT keratinocytes after UVB irradiation (20 mJ/cm2) or UVC (5 mJ/cm2), inflammatory mediators involved in sunburn onset.

However, it is important to note that astaxanthin should not be used as a substitute for adequate sun protection. It is not considered a UV filter and is not listed in Annex VI of Regulation (EC) No 1223/2009 on cosmetic products. It remains important to protect your skin from UV rays by using a sunscreen and limiting sun exposure during the hottest hours of the day. Astaxanthin can complement UV filters and strengthen skin protection against UV rays.

Advice : If you want a sun-kissed complexion without exposing your skin to UV rays, we recommend using a self-tanner. This product contains molecules that react with amino acids in the stratum corneum to form melanoidins (distinct from melanin), pigments that give the skin a brown tint. The self-tanners are a simple and safe way to achieve an even glow similar to a tan without sun exposure. Note that the colour they impart to the skin fades to disappear completely within 5 to 7 days.