Alpha Lipoic Acid recently gained GRAS (generally recognized as safe) status for food applications in the United States, and has been approved as a food in Japan.

Nutraingredients.com Feb 2005

 

Results of lab studies support the safety of ALA. The safety of ALA was assessed in acute and subchronic toxicity studies as well as in vitro and in vivo mutagenicity and genotoxicity studies. The "no observed adverse effect" level is considered to be 61.9 mg/kg bw/day

Regul Toxicol Phramacol. 2006 Oct;46(1): 29-41