I don’t know. The dose of broccoli you need to see clinical effects from the sulforaphane it contains is extremely high, but concentrated sulforaphane capsules are sold as a food supplement without needing to go through any FDA process.

What criterion does the FDA use to distinguish a food-derived chemical that needs to be treated as a drug, from one that’s still just seen as an extract/essence of the food itself, and therefore can be treated as a supplement? It seems very opaque to me.