How much sulforaphane is in broccoli?

A 100-gram serving of broccoli yields approximately 0.5 milligrams to 18 milligrams of sulforaphane. This estimate varies based on the amount of glucoraphanin (the sulforaphane precursor) in the broccoli and conversion rates from glucoraphanin to sulforaphane. Factors like the specific variety of broccoli, how it was grown, and its treatment before consumption can affect these amounts 1.