Section
How much sulforaphane per day
There is no established daily requirement. What exists is a set of doses that trials have used, and a large gap between label claims and delivered amounts.
Quick answer
There is no recommended daily intake for sulforaphane, because it is not an essential nutrient. Human trials have most often used amounts in the region of 10 to 60 mg of sulforaphane or its equivalent as glucoraphanin, usually daily for several weeks. What a supplement label promises and what it delivers are frequently different things.
This page answers the most common question on the subject, and the honest answer starts with what is not known. Sulforaphane is not an essential nutrient, so there is no reference intake, no deficiency state, and no official upper limit.
What can be described is the range of doses used in published human trials, and what a realistic portion of food provides. Both are covered here, with the caveat that converting between glucoraphanin on a label and sulforaphane in a person is the single largest source of confusion in this topic.
This page describes published research. It is general information, not medical advice, and it is not a recommendation to take anything. Sulforaphane and cruciferous-vegetable supplements can interact with medication. Talk to a doctor or pharmacist before starting a supplement, particularly if you are pregnant, breastfeeding, on anticoagulants, or being treated for thyroid disease.