How Much Sulforaphane Should I Take Daily?

November 26, 2025 •

4 min read

Clinical research suggests that an effective sulforaphane dosage for cellular support and detoxification often falls between 10 and 20 mg per day. Navigating how much sulforaphane should I take daily can be complex, as the amount you absorb depends heavily on your source, be it food or supplements, and how it is prepared.

Quick Summary

An effective daily sulforaphane dose is typically 10–20 mg for significant health benefits, though no standardized recommendation exists. The optimal amount depends on bioavailability, which is impacted by whether you use food or supplements and preparation methods.

Key Points

Optimal Dosage: Clinical studies suggest an effective daily dose of sulforaphane for cellular support is typically 10–20 mg.
Variable Absorption: The amount of sulforaphane your body absorbs varies greatly based on whether you consume it from food or supplements, and how the food is prepared.
Food vs. Supplements: Broccoli sprouts are the most potent food source, but supplements offer more consistent and higher potency doses, especially when stabilized.
Maximizing Bioavailability: To maximize sulforaphane from food, chop and wait before cooking, or add myrosinase-rich mustard powder to cooked cruciferous vegetables.
Safety First: Sulforaphane is generally safe, but higher doses from supplements can cause mild digestive upset. Consult a doctor if you are on medication or have thyroid issues.
Consistency is Crucial: Since sulforaphane is not stored long-term, consistent daily intake, rather than mega-dosing, is recommended for sustained health benefits.

Understanding Sulforaphane and Bioavailability

Sulforaphane is a potent plant compound, a type of isothiocyanate, found in cruciferous vegetables like broccoli, cabbage, and kale. It isn't present in its active form within the plant but is instead created when a precursor compound, glucoraphanin, comes into contact with the myrosinase enzyme. This happens when the vegetable is chopped, chewed, or damaged.

However, a protein known as the epithiospecifier protein (ESP) can interfere with this conversion, diverting it away from active sulforaphane. This is one of the key reasons why the amount of bioavailable sulforaphane can vary so dramatically between food sources and preparation methods. Myrosinase is also heat-sensitive, meaning prolonged cooking at high temperatures can destroy it, significantly reducing the amount of sulforaphane produced.

Recommended Daily Intake: What the Science Says

There is no official recommended daily intake (RDI) for sulforaphane, and studies have used a wide range of dosages depending on the health outcome being researched. However, based on clinical research, a few key ranges have emerged:

General Health Support

For general cellular support and detoxification, a daily dose of 10 to 20 mg is often cited as a reliable and effective range. Doses within this range have been shown to activate the Nrf2 pathway, which regulates antioxidant and detoxification enzymes.

Therapeutic and Higher Doses

For specific therapeutic purposes, some studies have used higher doses, occasionally reaching up to 40 mg per day or even higher in specialized cases. These higher concentrations are typically delivered via concentrated supplements and are not generally necessary for overall wellness. More is not always better with sulforaphane; consistency is key for long-term benefits.

Food Sources vs. Supplements

The most significant factor in your daily intake is whether you rely on food or supplements. Each has its own benefits and drawbacks related to consistency, potency, and cost.

Food Sources: The Natural Approach

Broccoli sprouts: These are the most potent natural source, containing up to 10–100 times more glucoraphanin than mature broccoli. Mildly heating them (e.g., light steaming) can boost bioavailability by deactivating ESP while preserving myrosinase.
Mature cruciferous vegetables: Broccoli, kale, cauliflower, and cabbage all contain sulforaphane precursors, but in much lower and more variable quantities. Chewing them thoroughly or adding myrosinase-rich foods can help.

Sulforaphane Supplements: Consistency and Potency

Stabilized Sulforaphane: Products like Prostaphane® or those containing Sulfodyne® deliver pre-formed, stabilized sulforaphane, ensuring high bioavailability (around 70%) and reliable dosing. They bypass the need for endogenous myrosinase conversion.
Glucoraphanin + Myrosinase: Supplements like Avmacol® combine the precursor and enzyme, which activate upon ingestion. Bioavailability is moderate and can vary depending on individual factors, though it is more consistent than relying on food alone.

Comparison: Sulforaphane from Diet vs. Supplements


Feature	Food Sources (e.g., broccoli sprouts)	Supplements (e.g., stabilized sulforaphane)
Dose Consistency	Highly variable based on freshness, variety, and prep.	Reliable and consistent dosage per serving.
Bioavailability	Moderate to high, depending on preparation.	High and consistent across individuals.
Ease of Use	Requires preparation (sprouting, chopping, chewing).	Convenient capsule or liquid form.
Other Nutrients	Rich in fiber, vitamins, and minerals.	Provides isolated compound; may lack other phytonutrients.
Considerations	Requires effort to maximize content; risk of contamination with sprouts.	Less variability, higher potency, but potentially higher cost.

Maximizing Your Sulforaphane Intake

For those who wish to rely on food, or enhance their supplement routine, here are some strategies:

Chop and Wait: Chop cruciferous vegetables like broccoli and let them sit for 40 minutes before cooking. This allows the myrosinase and glucoraphanin to fully react before heat denatures the enzyme.
Add Myrosinase Back: Sprinkle a myrosinase-rich powder, such as mustard seed powder, onto cooked broccoli or other crucifers to re-enable conversion.
Use Gentle Heat: Lightly steam vegetables for a few minutes instead of boiling or microwaving, which destroys the myrosinase enzyme. The optimal temperature is typically below 140°C (284°F).
Chew Thoroughly: Chewing raw vegetables properly maximizes the release and mixing of the myrosinase enzyme.

Safety and Side Effects

Sulforaphane is generally well-tolerated and considered safe, especially when consumed from food sources. Side effects are most often associated with supplements and typically involve mild gastrointestinal discomfort, such as gas, bloating, or diarrhea, particularly with high doses or on an empty stomach.

Serious interactions are rare but possible. Sulforaphane can affect liver enzymes (cytochrome P450) that process certain medications, including blood thinners and anticonvulsants, potentially altering their effectiveness. Individuals with thyroid conditions or those on medication should consult a healthcare provider before starting a supplement regimen. For pregnant or breastfeeding women, stick to food sources as supplement safety in these populations is not well-established.

Conclusion: A Personalized Approach

Ultimately, there is no single answer to how much sulforaphane should I take daily. For most people, a consistent, moderate daily dose of 10 to 20 mg is a good target for supporting cellular health and detoxification, according to research. The best approach is a personalized one, considering your dietary preferences, health goals, and tolerance. You can achieve this by eating plenty of properly prepared cruciferous vegetables, especially potent broccoli sprouts. Alternatively, high-quality, third-party tested supplements provide a consistent and reliable dose that can be easily integrated into a daily routine, especially for those seeking therapeutic benefits or a more precise intake. Consulting a healthcare provider is always recommended before starting any new supplement. An authoritative review of glucosinolate bioavailability can provide deeper insight into how these compounds are utilized by the body.

Frequently Asked Questions

While there's no official RDI, research suggests that a consistent daily dose of 10–20 mg is effective for activating key detoxification pathways in the body. Consistency is more important than taking very high doses.

It is difficult to get a reliably consistent, high dose of sulforaphane from just mature broccoli. Content varies by freshness and variety, and cooking destroys the necessary myrosinase enzyme. Broccoli sprouts are much more potent.

To maximize sulforaphane, chop your vegetables and let them sit for 40 minutes before lightly steaming them. You can also sprinkle myrosinase-rich mustard seed powder onto cooked vegetables to re-enable conversion.

It depends on the type of supplement. Stabilized sulforaphane supplements already contain the active compound and do not need myrosinase. Supplements that only contain the precursor, glucoraphanin, require added myrosinase to ensure conversion.

When taken in recommended amounts, sulforaphane is well-tolerated. High doses from supplements can cause mild and temporary gastrointestinal discomfort, such as gas, bloating, or diarrhea.

Doses over 40 mg have not been linked to harm in studies, but consistently taking moderate doses (e.g., 10-20 mg) is more effective than mega-dosing. Higher doses may increase the risk of digestive discomfort.

Individuals with thyroid conditions, those on medications that affect liver enzymes (e.g., certain blood thinners, blood sugar medications), and pregnant or breastfeeding women should consult a healthcare provider before taking supplements.