(S)-Ketamine

(R)-Ketamine and (S)-Ketamine are frequently combined to form ketamine. Although the effects of both forms are generally comparable, some effects may become more noticeable as the balance changes from a 50/50 combination.
(S)-Ketamine: More potent psychedelic and dissociative effects.
(R)-Ketamine: Stronger antidepressant effects that persist longer.