R+ Alpha Lipoic Acid contains 150 mg of R(+)-alpha-Lipoic acid per capsule. Common alpha-lipoic acid supplements are a 50/50 mixture of the natural R‑lipoic acid and the synthetic S‑lipoic acid; these mixtures are called “racemic mixtures” or “racemates.” In some cases, S(–)‑lipoic acid is simply less effective than R(+)‑lipoic acid. But in other cases, the S form actually acts in opposition to the activity of R‑lipoic acid. Only the R(+) enantiomer exists in nature; it is an essential cofactor of four mitochondrial enzyme complexes, and the only form our bodies can synthesize.