Sulforaphane (SFN) metabolite levels in plasma and urine following consumption of fresh broccoli sprouts and the broccoli sprout extract (BSE). Total levels (mean ± SEM) of SFN metabolites in plasma (A and C) and urine (B and D) of subjects at time 0 and at 3, 6, 12, 24, and 48 h after consuming broccoli sprouts (closed) or the BSE (open). (A and B) SFN metabolite levels detected following the single dose of 200 μmol SFN equivalents. (C and D) SFN metabolite levels following two 100-μmol SFN doses consumed within a single day. Insets: Close-up of SFN metabolite levels at 12 and 24 h in (A and C) plasma and (B and D) urine. Arrows indicate times of SFN consumption. Free SFN was only detected in four subjects at 3 h following the single dose and comprised < 2% of total SFN metabolites (data not included). *p < 0.05, **p < 0.01, ***p < 0.001.