Geissbühler F, Raffin Y, Combépine C, Streiff U, Hovaguimian T
J Clin Chem Clin Biochem. 1978 Jun;16(6):355-8.
The fasting level of 3-O-methyldopa in human plasma is 120 +/- 18 nmol/1. Four hours after a single dose of 425 mumol benserazid, the level increased to 313 +/- 69 nmol/1.