A trial evaluating the skin moisturizing function and facial condition of 80 healthy women found that at week 8, the ergothioneine group had significantly higher skin moisture content in the temples than the placebo group. At week 12, the skin moisture content in the arms also increased significantly. After 12 weeks, the facial wrinkle and texture scores of the ergothioneine group were significantly better than those of the placebo group.

Studies have shown that ergothioneine can effectively protect skin cells from DNA damage caused by ultraviolet B (UVB) radiation and reduce UVB-induced apoptosis in vitro.

Ergothioneine is a powerful antioxidant that neutralizes free radicals, protects cells from oxidative damage, and slows the aging process. A study suggests that ergothioneine may represent a new vitamin whose physiological effects include antioxidant cell protection.

Studies have shown that ergothioneine (EGT) may prevent cisplatin-induced neuronal damage and enhance cognitive ability by inhibiting oxidative stress and inflammatory pathways, thereby alleviating the neurodegenerative complications of diabetes (such as Alzheimer's disease).

A clinical study concluded that daily oral administration of 500 mg of L-cystine and 250 mg of L-glutathione for 12 weeks is a safe treatment that can effectively whiten the skin and reduce the size of facial dark spots in Asian women, and is safe and effective for long-term use.