[The effect of L-tryptophan on L-dopa absorption (author's transl)].

Dopa blood levels were measured in healthy subjects after oral intake of 0.5 g L-dopa (seven subjects) as well as of 0.5 g L-dopa and 1.0 g L-tryptophan (six subjects). Combined L-dopa and L-tryptophan administration produced significantly less of a rise in dopa blood levels than L-dopa alone.