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Botanical
Broccoli Sprout Extract
Brassica oleracea var. italica sprout extract
Evidence TierCWADA NOT PROHIBITED
watchEffect Window
Human trials generally assess outcomes over weeks to months.
check_circleCompliance
WADA NOT PROHIBITED
Overview
Clinical Summary
Broccoli sprout extract is a sulforaphane delivery tool with emerging human evidence in selected metabolic and neurobehavioral settings, but responses are subgroup- and formulation-dependent.
Broccoli sprout extract is usually sold for detox and antioxidant support, but the meaningful human evidence is narrower and more interesting. Sulforaphane-rich preparations have produced signals in autism-spectrum-disorder symptom studies and in a recent prediabetes trial with clear responder heterogeneity. That means the supplement is plausible and modern, but still not a broad general-health recommendation.
Sulforaphane activates cytoprotective and antioxidant-response pathways, but clinical effects depend heavily on formulation, conversion to active compound, and host microbiome factors.
Outcomes
What This Is Expected To Influence
Primary Outcomes
- Small subgroup-dependent improvement in fasting glucose in prediabetes
Secondary Outcomes
- Experimental symptom improvement signals in autism-spectrum disorder
Safety
Contraindications and Interactions
Contraindications
No entries provided
Side effects
- GI upset
Interactions
No entries provided
Avoid if
- You are treating it as a generic detox supplement without a defined goal
Evidence
Study-level References
bro-SRC-001Randomized controlled trial
Sourceopen_in_newDwibedi C, Axelsson AS, Abrahamsson B, Fahey JW, Asplund O, Hansson O, Ahlqvist E, Tremaroli V, Bäckhed F, Rosengren AH. Effect of broccoli sprout extract and baseline gut microbiota on fasting blood glucose in prediabetes: a randomized, placebo-controlled trial. Nat Microbiol. 2025;10(3):681-693. doi:10.1038/s41564-025-01932-w. PMID:39929977.
Population: Drug-naive adults with prediabetes.
Dose protocol: Daily broccoli sprout extract for 12 weeks
Key findings: Small overall glucose effect with stronger responder subgroup.
Notes: Best modern metabolic trial.
Paper content
This 12-week randomized, double-blind, placebo-controlled trial enrolled 74 drug-naive adults with prediabetes and tested daily broccoli sprout extract against placebo. The prespecified primary target, a 0.3 mmol/L placebo-adjusted fasting-glucose reduction, was not met. The overall placebo-adjusted reduction was 0.2 mmol/L, which was statistically significant but small. Exploratory analyses suggested a stronger 0.4 mmol/L reduction in a responder subgroup characterized by mild obesity, lower insulin resistance, reduced insulin secretion, and a gut microbiota profile better able to convert precursor compounds into active sulforaphane. Gastrointestinal side effects occurred, but no severe adverse events were reported.
bro-SRC-002Randomized controlled trial
Sourceopen_in_newSingh K, et al. Sulforaphane treatment of autism spectrum disorder (ASD). Proc Natl Acad Sci U S A. 2014. doi:10.1073/pnas.1416940111. PMID:25313065.
Population: Young men aged 13 to 27 years with moderate to severe autism spectrum disorder.
Dose protocol: Sulforaphane-rich extract for 18 weeks
Key findings: Behavioral improvement signal in ASD.
Notes: Landmark exploratory ASD trial.
Paper content
This landmark sulforaphane trial found meaningful behavioral improvements in some males with moderate to severe autism spectrum disorder, but it was still a small study and the findings remain population specific.
bro-SRC-003Randomized, double-blind, placebo-controlled trial.
Sourceopen_in_newYusin J, Wang V, Henning SM, et al. The Effect of Broccoli Sprout Extract on Seasonal Grass Pollen-Induced Allergic Rhinitis. Nutrients. 2021;13(4):1337. doi:10.3390/nu13041337. PMID:33920642.
Population: Adults with confirmed grass pollen-induced allergic rhinitis.
Dose protocol: Broccoli sprout extract plus nasal steroid for 3 weeks with grass pollen challenge
Key findings: Nasal airflow and symptom scores improved significantly compared to placebo groups post-allergen challenge.
Notes: Small short-term RCT providing preliminary human allergy signal for BSE.
Paper content
This double-blind RCT tested broccoli sprout extract as an adjunct for seasonal grass pollen allergic rhinitis. The combination of nasal corticosteroid plus BSE produced the most significant improvements in nasal airflow and symptom scores compared to placebo groups at multiple post-challenge time points. However, no significant cytokine changes were detected in nasal mucus. The study is small and uses a short three-week window with allergen challenge rather than a prolonged real-world exposure. It provides a preliminary human signal for BSE in allergic airway inflammation, supporting the Nrf2-antioxidant mechanism in a clinical setting.
bro-SRC-004Randomized, parallel-group, double-blind, placebo-controlled trial
Sourceopen_in_newZimmerman AW, Singh K, Connors SL, Liu H, Panjwani AA, Lee LC, Diggins E, Foley A, Melnyk S, Singh IN, James SJ, Frye RE, Fahey JW. Randomized controlled trial of sulforaphane and metabolite discovery in children with Autism Spectrum Disorder. Mol Autism. 2021;12(1):38. doi:10.1186/s13229-021-00447-5. PMID:34034808.
Population: Children with autism spectrum disorder aged 3 to 12 years.
Dose protocol: Oral sulforaphane-rich preparation for 15 weeks in children with autism spectrum disorder
Key findings: The primary OACIS endpoint was not significantly different from placebo, but secondary caregiver-rated ABC outcomes improved at 15 weeks.
Notes: Important corrective trial because it tempers the stronger signal from the earlier exploratory autism study.
Paper content
This 15-week randomized, double-blind, placebo-controlled trial tested sulforaphane in 57 children with autism spectrum disorder. The primary OACIS endpoint was not significantly different from placebo at either 7 or 15 weeks, which is the key corrective point for supplement framing. Caregiver-rated secondary outcomes on the Aberrant Behavior Checklist improved at 15 weeks, and biomarker analyses suggested effects on glutathione redox status, mitochondrial respiration, inflammatory pathways, and heat-shock responses. The trial was safe and well tolerated, but the clinical signal was mixed and more placebo-sensitive than the earlier young-adult autism study.