Sulforaphane

Broccoli sprout extract · Glucoraphanin · Broccoli sprouts

Snapshot

Indications	Contraindications
Lung cancer risk in former smokers¹ Autism spectrum symptoms² Schizophrenia symptoms^3–5 Prediabetes glucose⁶ Exercise muscle damage^{7, 8} Helicobacter pylori gastritis⁹	Pregnancy or nursing¹⁰ Prescription nitrates¹⁰

Sulforaphane is an isothiocyanate released by the enzyme myrosinase from glucoraphanin, which broccoli sprouts contain in high amounts⁹. It activates cellular antioxidant and detoxification pathways¹¹. That effect underlies its use in cancer chemoprevention, glucose and liver support, and symptom support in autism spectrum disorder and schizophrenia.

Evidence is mixed. A randomized trial in former smokers lowered a bronchial proliferation marker without changing histopathology¹. A prediabetes trial missed its primary glucose endpoint, and a hemodialysis trial found no change in inflammatory gene expression. A 2024 review of clinical studies since 2018 found most sulforaphane trials addressed autism spectrum disorder and schizophrenia, with minimal toxicity, and called for better-designed trials¹². Products listing sulforaphane are mostly capsules, with liquids and tablets also sold; forms differ in how they deliver sulforaphane, see Form comparison.

Memorial Sloan Kettering directs patients with advanced pancreatic cancer to talk with their healthcare provider, because high-dose sprout supplements during chemotherapy increased nausea and vomiting⁹.

Last updated October 16, 2026. Read how we make monographs.

In the full monograph

66 sources, 53 studies

When to useThe situations practitioners use it for, each with the reason and the study behind it.
SafetyWho should avoid it, who needs extra care, and the side effects reported in studies.
InteractionsThe medicines and supplements it interacts with, the effect of each, and what labeling says to watch.
Protocol notesThe doses used in studies, how and when they were taken, and how the forms on the market compare.
How it worksWhat it is and how it works in the body, in plain terms.
Published studiesThe studies behind each use, popular claims checked against them, and trials still under way.
Word of mouthWhat patients and practitioners report online, kept separate from the clinical evidence.
Clinical perspectiveA closing read of where the evidence is solid, where it is thin, and what has not been studied.

Snapshot

In the full monograph

Sources