An enzyme with antioxidant and possibly anti-inflammatory effects.
While studies of alpha lipoic acid do exist, few of them were carried out on people, and none were double-blind in an attempt to evaluate its effects on wrinkling (Sources: British Journal of Dermatology, October 2003, pages 841–849; and Clinical & Experimental Dermatology, October 2001, pages 578–582).
The majority of alpha lipoic acid research was done on human dermal fibroblasts in vitro (test tube) in cell-culture systems. In vitro results are interesting, but it’s not known if the results translate to human skin. These models do mimic human skin, but something that mimics human skin is not the same as living skin.
Note that alpha lipoic acid is extremely vulnerable to degradation by sunlight (Source: Journal of Clinical Biochemistry and Nutrition, May 2009, pages 218–222). Lastly, higher amounts of alpha lipoic acid (5% or greater) are capable of causing burning or stinging sensations or a mild rash on skin.
Source – beautypedia