Sulforaphane (Broccoli Sprout Extract)

Supplements · Antioxidants · Supplement, Typed Supps

A compound from broccoli sprouts that switches on your body’s own antioxidant and detox systems — well proven at the biomarker level, less proven for specific diseases.

Stage by stage

Intake (Broccoli sprout extract or raw sprouts): Chewing or processing activates the plant enzyme myrosinase.
Conversion & absorption (Glucoraphanin to sulforaphane): Myrosinase (plant or gut bacterial) converts the precursor into active sulforaphane, which is then absorbed.
Bloodstream (Circulates): Sulforaphane is notably well absorbed and distributes to tissues throughout the body.
Cellular defense pathway (Nrf2 activation): Switches on the Nrf2 pathway, boosting the body’s own antioxidant and detoxification enzymes.

What the evidence supports

Activating the body's Nrf2 antioxidant and detoxification enzyme pathway — moderate evidence. This is the best-documented human effect — multiple studies show sulforaphane reliably boosts phase II detoxification enzyme activity and antioxidant markers, though this is a biomarker response, not yet a proven disease outcome.
Improving behavioral symptoms in autism spectrum disorder — limited evidence. A randomized placebo-controlled trial in young men with moderate-to-severe ASD found improved behavioral scores after 18 weeks of broccoli sprout extract, but this is a single trial in a specific population and hasn't been consistently replicated since.
Evidence on Short-term tolerability across studied dose ranges — moderate evidence. Phase 1 studies and cancer-prevention trials using doses up to 200μmol/day found no dose-limiting toxicities or serious adverse events, though mild gastrointestinal upset (gas, bloating) is commonly reported.

Typical dose

Trials have used the equivalent of roughly 50–200μmol of sulforaphane or its glucosinolate precursor per day, most often from broccoli sprout extract.

Upper limit: No established UL

Timing

No strict timing requirement; product formulation (active myrosinase or stabilized sulforaphane) matters more than when you take it.

Time to effect

Hours to days: Antioxidant and detox enzyme activity rises within hours to days of dosing.
Months: Trials testing behavioral or metabolic outcomes (e.g., the autism trial) dosed continuously for 18 weeks before assessing results.

Common myth

“Cooking broccoli doesn’t affect its sulforaphane content.” In reality: Heavy cooking destroys the myrosinase enzyme needed to convert glucoraphanin into active sulforaphane, substantially reducing how much your body can access — raw or lightly steamed cruciferous vegetables (or supplements with preserved myrosinase) deliver more.