Home Ingredients Sulforaphane / Glucoraphanin
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Sulforaphane / Glucoraphanin

Brassica oleracea var. italica
Evidence Level
Moderate
3 Clinical Trials
8 Documented Benefits
3/5 Evidence Score

Sulforaphane is a well-studied natural NRF2 activator, a sulfur-containing compound formed when glucoraphanin (the precursor found in cruciferous vegetables, especially broccoli sprouts) is hydrolyzed by the enzyme myrosinase. NRF2 activation triggers the body's master antioxidant response, upregulating glutathione, NQO1, HO-1, and dozens of other detoxification and antioxidant enzymes for 24+ hours per dose. Human trials are small and scattered: modest, conditional effects on blood glucose in type 2 diabetes and prediabetes, increased urinary excretion of pollutant metabolites, and a single small unreplicated trial in autism. Population data link cruciferous vegetable intake to lower cancer risk. Broccoli sprouts naturally contain 10-100x more glucoraphanin than mature broccoli. Effective doses: 10-40 mg sulforaphane equivalent or 60-150 mg glucoraphanin with active myrosinase. Truebroc® (Brassica Protection Products) is the most-studied standardized broccoli seed extract. The honest framing: genuine NRF2 activator whose human evidence is real but preliminary and spread thinly across indications; stability is a real challenge (sulforaphane degrades rapidly); products need to provide either stabilized sulforaphane OR glucoraphanin with active myrosinase for in-vivo conversion.

Studied Dose 60-150 mg glucoraphanin (with active myrosinase) = 10-40 mg sulforaphane equivalent; direct sulforaphane 10-40 mg/day.
Active Compound Sulforaphane (NRF2 activator) and its precursor glucoraphanin; myrosinase enzyme required for conversion; Truebroc® broccoli seed extract.

Benefits

NRF2 activation (master antioxidant response)

Sulforaphane is a potent natural NRF2 activator that upregulates antioxidant and detoxification enzymes (glutathione, NQO1, HO-1, others), with induction lasting roughly 24 hours per dose. Mechanism foundation distinguishing it from typical antioxidant supplements that don't induce endogenous antioxidant systems.

Supported by Trial 2, Trial 3

Blood glucose and metabolic biomarkers

In type 2 diabetes, concentrated broccoli sprout extract lowered fasting blood glucose and HbA1c, mainly in an obese, poorly controlled subgroup (Axelsson 2017). In prediabetes, fasting glucose fell only in a gut-microbiota-defined responder subgroup (Dwibedi 2025). Effects are modest and conditional, not uniform.

Supported by Trial 2

Autism: one small trial (preliminary)

A single small placebo-controlled trial (Singh 2014, 44 young men with autism) reported improvements in social responsiveness and behavior on sulforaphane, with the gains reversing after it was stopped. The result has not been robustly replicated and comes from one small study in a disease population.

Supported by Trial 1

Schizophrenia: preliminary research only

Early small studies have tested sulforaphane alongside antipsychotic therapy for cognitive symptoms in schizophrenia, with mixed and preliminary results. This use is investigational and is not supported by any trial cited on this page.

Supported by Trial 1, Trial 2

Detoxification enzyme support

Sulforaphane upregulates Phase II detoxification enzymes that support clearance of environmental toxins, pollutants, and pro-carcinogens. This is an enzyme-induction mechanism, not a measured human disease outcome.

Supported by Trial 3, Trial 2

Cruciferous intake and cancer risk (population data)

Substantial preclinical and population research suggests cruciferous vegetable consumption is associated with reduced cancer risk. Human clinical trials of sulforaphane supplementation for cancer prevention are still emerging; promising but not definitively established.

Supported by Trial 2

Stability and bioavailability challenges

Sulforaphane is unstable — degrades rapidly in heat, light, and acid. Quality products provide either stabilized sulforaphane or glucoraphanin + active myrosinase enzyme for in-vivo conversion. Generic 'broccoli extract' without myrosinase may have minimal bioavailable sulforaphane despite labeled content.

Supported by Trial 1

Sourcing and form considerations

Broccoli sprouts naturally contain 10-100x more glucoraphanin than mature broccoli. Sprouts (1-2 oz daily) provide therapeutic doses; mature broccoli requires very high consumption. Supplements bypass the dietary intake limitation. Quality of myrosinase preservation matters significantly.

Supported by Trial 1

Mechanism of action

1

Nrf2-Keap1 pathway activation

Sulforaphane modifies cysteine residues on Keap1 (the Nrf2 repressor protein), preventing Keap1-mediated Nrf2 ubiquitination and proteasomal degradation. Free Nrf2 translocates to the nucleus and binds antioxidant response elements (AREs), inducing transcription of over 200 cytoprotective genes simultaneously.

2

Histone deacetylase (HDAC) inhibition

Sulforaphane inhibits class I and II histone deacetylases, maintaining chromatin in a more open, transcription-accessible state. This epigenetic mechanism is studied in relation to cancer prevention in preclinical work, independently of Nrf2 activation.

3

Phase II detoxification enzyme induction

Sulforaphane induces glutathione S-transferases (GSTs), NQO1 (NAD(P)H quinone oxidoreductase), and epoxide hydrolases that convert reactive carcinogen metabolites to water-soluble mercapturic acid conjugates for urinary excretion — providing systemic chemoprotection.

Clinical trials

1
Sulforaphane and Autism Spectrum Disorder — Johns Hopkins RCT
PubMed

Randomized, double-blind, placebo-controlled trial of sulforaphane (50–150 μmol/day from broccoli sprout extract) in 29 young men with moderate-to-severe ASD for 18 weeks.

29 young men with ASD aged 13–27. 18-week intervention.

Sulforaphane significantly improved social responsiveness (SRS: -34%), aberrant behavior (ABC: -17%), and social communication vs. placebo. Effects reversed upon discontinuation. No serious adverse events. This is a single small trial that has not been robustly replicated.

2
Sulforaphane and Blood Glucose in Type 2 Diabetes — Science Translational Medicine
PubMed

Clinical trial examining sulforaphane (concentrated broccoli sprout extract delivering ~150 μmol sulforaphane/day) in 97 patients with type 2 diabetes for 12 weeks.

97 T2DM patients. 12-week intervention.

Sulforaphane significantly reduced fasting blood glucose (significant in obese dysregulated subgroup) and HbA1c vs. placebo. Mechanism confirmed as NRF2-mediated suppression of glucose production enzymes in liver. Published in Science Translational Medicine.

3
Sulforaphane and Air Pollutant Detoxification — China RCT
PubMed

Randomized, placebo-controlled trial of broccoli sprout beverage (delivering ~26–40 μmol sulforaphane/day) in 291 healthy adults in polluted Jiangsu province, China for 12 weeks.

291 healthy adults in heavily polluted region. 12-week intervention.

Broccoli sprout drink significantly increased urinary excretion of the mercapturic acids of benzene (61%) and acrolein (23%) versus placebo, but not crotonaldehyde. This is a detoxification biomarker, not a measured reduction in disease.

Side effects and drug interactions

Common Potential side effects

Generally well tolerated at clinical doses
GI discomfort and flatulence possible — especially with high doses of broccoli sprout preparations
Sulfurous body odor/breath at high doses (same mechanism as garlic odor)
Hypothyroid individuals should use caution — glucosinolates may mildly affect thyroid at very high doses

Important Drug interactions

Anticoagulants (warfarin) — sulforaphane induces CYP1A2 and CYP2B6; may alter warfarin metabolism; monitor INR
Chemotherapy: sulforaphane affects drug-metabolizing enzymes and has complex, mostly preclinical interactions with cancer therapy; discuss with your oncologist before combining
CYP substrates — Nrf2 induction affects multiple CYP enzymes; potential interactions with medications metabolized by CYP1A2, 2B6

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Frequently asked questions about Sulforaphane / Glucoraphanin

How much sulforaphane should I take?

Doses vary by product; studies often use broccoli sprout extracts standardized to provide roughly 10 to 40 mg of sulforaphane (or its precursor glucoraphanin) per day. Because conversion varies, products with active myrosinase enzyme deliver more usable sulforaphane.

What is sulforaphane used for?

Sulforaphane, concentrated in broccoli sprouts, is studied for antioxidant and detoxification support (it activates the body's Nrf2 pathway), cellular protection, and healthy inflammation. It is one of the most researched compounds from cruciferous vegetables.

Why does myrosinase matter in sulforaphane supplements?

Sulforaphane forms from glucoraphanin only when the enzyme myrosinase is present. Many supplements provide glucoraphanin but lose myrosinase in processing, lowering actual sulforaphane. Products that preserve or add active myrosinase deliver more of the active compound.

Is sulforaphane safe?

Sulforaphane from broccoli and sprout extracts is generally well tolerated; some people get mild digestive upset. As with any concentrated cruciferous product, those with thyroid concerns or on medication should check with a doctor.

What is Sulforaphane / Glucoraphanin?

Sulforaphane is a well-studied natural NRF2 activator, a sulfur-containing compound formed when glucoraphanin (the precursor found in cruciferous vegetables, especially broccoli sprouts) is hydrolyzed by the enzyme myrosinase.

What is Sulforaphane / Glucoraphanin used for?

Sulforaphane / Glucoraphanin is researched primarily for Antioxidant, Metabolic Health, and Detox & Cleanse. Sulforaphane is a potent natural NRF2 activator that upregulates antioxidant and detoxification enzymes (glutathione, NQO1, HO-1, others), with induction lasting roughly 24 hours per dose.

What is the recommended dosage of Sulforaphane / Glucoraphanin?

The clinically studied dose is 60-150 mg glucoraphanin (with active myrosinase) = 10-40 mg sulforaphane equivalent; direct sulforaphane 10-40 mg/day. Always follow the product label and check with a healthcare provider for personal advice.

Is Sulforaphane / Glucoraphanin safe, and does it have side effects?

For most healthy adults, Sulforaphane / Glucoraphanin is well tolerated at studied doses. Reported effects can include: Generally well tolerated at clinical doses GI discomfort and flatulence possible — especially with high doses of broccoli sprout preparations It may also interact with some medications. Sulforaphane / Glucoraphanin is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Sulforaphane / Glucoraphanin interact with any medications?

Possible interactions include: Anticoagulants (warfarin) — sulforaphane induces CYP1A2 and CYP2B6; may alter warfarin metabolism; monitor INR Chemotherapy: sulforaphane affects drug-metabolizing enzymes and has complex, mostly preclinical interactions with cancer therapy; discuss with your oncologist before co… If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Sulforaphane / Glucoraphanin?

NutraSmarts rates the evidence for Sulforaphane / Glucoraphanin as Moderate (3 out of 5). It is backed by 3 clinical trials and 5 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(5 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Singh K, Connors SL, Macklin EA, Smith KD, Fahey JW, Talalay P, et al. Sulforaphane treatment of autism spectrum disorder (ASD). Proc Natl Acad Sci U S A. 2014;111(43):15550-5. doi: 10.1073/pnas.1416940111.PubMedUsed to support: Preliminary autism signal: small placebo-controlled RCT (n=44) reporting behavioral improvement in young men with autism on sulforaphane. Findings are preliminary, the sample was small, and the autism result has not been robustly replicated.
  2. Egner PA, Chen JG, Zarth AT, Ng DK, Wang JB, Kensler KH, et al. Rapid and sustainable detoxication of airborne pollutants by broccoli sprout beverage: results of a randomized clinical trial in China. Cancer Prev Res (Phila). 2014;7(8):813-23. doi: 10.1158/1940-6207.CAPR-14-0103.PubMedUsed to support: Supports detox/Nrf2 claim: RCT showing a glucoraphanin/sulforaphane broccoli-sprout beverage increased urinary excretion of airborne pollutants (benzene, acrolein) in a highly polluted region, consistent with Nrf2-mediated detoxification. A biomarker outcome, not a clinical disease endpoint.
  3. Houghton CA, Fassett RG, Coombes JS. Sulforaphane: translational research from laboratory bench to clinic. Nutr Rev. 2013;71(11):709-26. doi: 10.1111/nure.12060.PubMedUsed to support: Mechanistic/clinical Nrf2 review: summarizes sulforaphane as a potent Nrf2 activator with promising but still largely preclinical and early-clinical evidence. Supports framing the human clinical evidence as preliminary.
  4. Dwibedi C, Axelsson AS, Abrahamsson B, Fahey JW, Asplund O, Hansson O, et al. 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):681-93. doi: 10.1038/s41564-025-01932-w.PubMedUsed to support: Preliminary metabolic signal: RCT in prediabetes found broccoli sprout extract (sulforaphane) modestly lowered fasting glucose, but only in a microbiota-defined responder subgroup. Illustrates that sulforaphane's clinical effects are small and conditional, reinforcing preliminary framing.
  5. Axelsson AS, Tubbs E, Mecham B, Chacko S, Nenonen HA, Tang Y, Fahey JW, Derry JMJ, Wollheim CB, Wierup N, Haymond MW, Friend SH, Mulder H, Rosengren AH. Sulforaphane reduces hepatic glucose production and improves glucose control in patients with type 2 diabetes. Sci Transl Med. 2017;9(394):eaah4477. doi: 10.1126/scitranslmed.aah4477.PubMedUsed to support: Placebo-controlled trial in patients with type 2 diabetes: concentrated broccoli sprout extract (about 150 micromol sulforaphane/day for 12 weeks) reduced fasting blood glucose and HbA1c, with the effect concentrated in obese, poorly controlled participants. The effect is modest and subgroup-dependent, and the mechanistic work behind it was largely in cells and animals.