What is sulforaphane?

Where it comes from

Cruciferous vegetables store a compound called glucoraphanin, a glucosinolate. They also produce an enzyme called myrosinase. In an undamaged plant the two are kept apart, in separate cellular compartments.

When the plant is cut, chewed, crushed or blended, those compartments break and the enzyme meets the precursor. Myrosinase strips the sugar off glucoraphanin, the remaining fragment loses a sulfate group and rearranges, and the result is sulforaphane.

This is a defense mechanism. The plant is not making a supplement ingredient; it is making something unpleasant for whatever is eating it, at the moment it is being eaten.

Why that matters in practice

Because the compound is made on demand rather than stored, how you handle the food changes how much you get. Heat destroys myrosinase. Chopping and waiting before cooking gives the enzyme time to work. Chewing thoroughly does more than swallowing quickly. These are not marginal effects. The broccoli sprouts section applies this to the food where it matters most.

It also explains the confusion around supplements. A product containing glucoraphanin has the precursor but may have no working enzyme, in which case conversion depends on gut bacteria, which vary widely between people.

Is it an essential nutrient?

No. There is no deficiency state, no recommended intake and no established requirement. Sulforaphane is a compound found in some foods that has been studied for possible effects, which is a different thing from a nutrient the body needs.