Erythrulose

Erythrulose is a self-tanning sugar (often used around ~1–5%) that reacts with amino acids in the stratum corneum, similar to but generally milder than DHA. Clinical and consumer reports suggest it is usually well-tolerated, but the Maillard-type reaction and resulting byproducts can cause stinging, dryness, or eczema flares in reactive or barrier-impaired skin, especially with frequent use or when layered with exfoliants. Given the non-trivial but typically low irritation potential in sensitive populations, it fits best as a gentle (not exceptionally gentle) ingredient. Safety Notes: In consumer self-tanning products, erythrulose is used at very low levels (~0.1–0.5%) as a tone-modifier/“anti-orange” adjunct to DHA and in gradual tanners, while standard leave-on mousses/lotions commonly sit around 1–3%. High-strength OTC self-tanning drops and intensifying concentrates intended for mixing with moisturizers are observed up to about 5–8% erythrulose, typically paired with DHA; rinse-off products rarely rely on erythrulose because it needs leave-on contact time to develop color. No specific EU/FDA maximum applies for erythrulose in cosmetics, so practical stability/odor and consumer tolerability drive the upper end.