Benefits, Uses, Side Effects, and More

Sulforaphane is a sulfur-rich compound found in certain species of the Brassica vegetable family. It’s found in broccoli and other cruciferous vegetables, like bok choy, kale, and cabbage.

The inactive form of sulforaphane is glucoraphanin. When you cut, chop, or chew vegetables, it releases compounds called myrosinase enzymes. These enzymes convert glucoraphanin to sulforaphane’s active form, isothiocyanate. Your body can only use sulforaphane in its active form.

Sulforaphane has antioxidant and anti-inflammatory effects. Research shows potential benefits related to blood sugar control, cancer prevention, brain and cardiovascular health, and more. Sulforaphane supplements continue to gain popularity among people pursuing health and wellness goals.

Cardiovascular (heart and blood vessel) disease affects millions of people worldwide. Oxidative stress—cell damage caused by high levels of compounds called free radicals—can influence heart disease risk. Antioxidants neutralize free radicals and help prevent oxidative stress.

Sulforaphane has many antioxidant and anti-inflammatory properties that help fight oxidative stress and may benefit heart health.

Sulforaphane activates processes that defend against oxidative stress, lowering the risk of atherosclerosis (plaque buildup in the arteries) and other cardiovascular conditions. For example, it can help lower blood pressure by improving blood vessel function.

Animal studies have shown that sulforaphane may also help regulate cholesterol levels by increasing high-density lipoprotein (HDL, or “good”) cholesterol and reducing low-density lipoprotein (LDL, or “bad”) cholesterol.

Sulforaphane may play a key role in blood sugar management. Oxidative stress and inflammation contribute to insulin resistance, a trait of type 2 diabetes. Sulforaphane’s antioxidant and anti-inflammatory effects may help improve insulin sensitivity.

One study found that sulforaphane, in the form of broccoli sprout extract, can help lower fasting blood glucose (sugar) and hemoglobin A1c (HbA1c) levels in people with uncontrolled type 2 diabetes. High HbA1c levels are a marker of diabetes.

Recent animal and test tube studies have also shown consuming sulforaphane-rich foods or supplements may improve fasting blood sugar (levels after not eating for 8 hours) and fasting insulin serum in those who eat a high-fat diet.

More research is needed to understand sulforaphane’s effects on blood sugar control fully. Make sure to follow medical advice from your healthcare provider.

Some studies suggest that sulforaphane’s anticancer properties may inhibit tumor cell growth. Its anti-inflammatory and antioxidant effects help combat chronic (long-lasting) inflammation and oxidative stress, which are often associated with cancer development.

However, research has also shown that sulforaphane can influence detoxification enzymes that help the body eliminate toxins and potential carcinogens (cancer-causing substances).

While sulfophorane’s anticancer effects are promising, most research on the topic has used concentrated sources of the phytochemical. Further research is needed to understand its mechanisms and determine its role in cancer treatment and prevention.

Although research is limited, sulforaphane may help treat symptoms of autism. A study involving young men with autism spectrum disorder found that a daily dose of 50-150 micromoles of sulforaphane improved various symptoms. The dose enhanced social interaction, behavior, and verbal communication.

Another more recent study examined sulforaphane’s effects on autism symptoms in children and found similar results. Children who received sulforaphane supplementation saw improvements in autism symptoms.

The researchers leading the study noted the need for further studies before sulforaphane can be recommended as part of a medical treatment plan.

There are currently no daily intake recommendations for sulforaphane. For people who want to increase their dietary intake of sulforaphane, it is most commonly available in cruciferous vegetables, such as:

• Broccoli
• Broccoli sprouts
• Kale
• Brussels sprouts
• Cabbage
• Bok choy
• Cauliflower

Sulforaphane is also widely available as a supplement in tablet, capsule, powder, or liquid form. Most sulforaphane supplements are made using broccoli, broccoli seeds, or broccoli sprout extracts.

Sulforaphane is primarily consumed through whole foods that can be eaten raw, cooked, or as part of multi-ingredient dishes. People who prefer a more concentrated source of sulforaphane may choose dietary supplements.

There are no standardized recommendations for taking sulforaphane supplements. Many manufacturers recommend taking the supplement with myrosinase to enhance sulforaphane production in the body. Taking it with a meal may also enhance its absorption.

Results may vary depending on your medical history, dosage, and how often you take the supplement. Some notice subtle improvements quickly, while others take longer to experience noticeable effects.

It’s important to talk to your healthcare provider before starting a new supplement. They can ensure proper dosage for safety and optimal results.

Dosage 

Researchers have not yet established a standardized dose of sulforaphane, and recommendations vary widely between supplement brands. Studies have examined daily oral doses ranging from 9.9-847 micromoles of sulforaphane and 25-800 micromoles of glucoraphanin. More research is needed to determine the ideal dose for health, effectiveness, and safety.

Before starting a new supplement, it’s best to discuss your individual needs with a healthcare professional who can account for your medical history, dietary intake, and health goals.

While no established upper limit for sulforaphane exists, animal studies have noted evidence of toxicity at specific doses.

Some animals experienced adverse effects after consuming 150-300 milligrams (mg) of sulforaphane per kilogram (kg) of body weight. For example, some mice experienced increased sedation, decreased body temperature, impaired motor coordination, and decreased skeletal muscle strength.

While sulforaphane has been linked to many health benefits that may prevent or treat chronic health conditions, research on its long-term safety is needed. There is also no or limited research regarding sulforaphane’s effects on pregnant or breastfeeding individuals.

Speak with your healthcare provider before starting a new supplement to ensure its safety based on your medical history.

Potential Drug Interactions

Research on sulforaphane and potential drug interactions is limited. An older study found that sulforaphane supplements may interact with certain medications, partly due to sulforaphane’s ability to influence drug-metabolizing enzymes.

Researchers found that the supplement may alter the effectiveness of certain diuretics, calcium channel blockers, and nonsteroidal anti-inflammatory drugs (NSAIDs).

It’s important to consult a healthcare provider before combining sulforaphane supplements with medications. A medical doctor can help you safely incorporate sulforaphane into your routine and avoid adverse drug interactions.

What To Look For

Sulforaphane supplements can be found online and in various health food stores. The United States Food and Drug Administration (FDA) does not regulate dietary supplements. Choose reputable supplement brands and look for third-party tested products to ensure their purity and safety.

Whether you choose sulforaphane capsules, powder, or liquid extracts, take note of the recommended dose and any additional ingredients.

Can You Take Too Much?

While research regarding sulforaphane toxicity is limited, animal studies suggest that excessive intake may cause negative effects.

There is no determined upper limit for sulforaphane, but researchers examining its effects on mice found that doses of 150-300 mg/kg of body weight caused adverse reactions in some mice.

Researchers noted increased sedation and decreased body temperature with doses of 150-300 mg/kg, impaired motor coordination with 200-300 mg/kg doses, and decreased muscle strength with 250-300 mg/kg doses.

This research was done on animals, so it’s unknown if the supplement dose would have similar effects on humans.

Sulforaphane is generally considered safe due to its lack of adverse effects. Side effects of sulforaphane vary between individuals, and the most common include:

Some animal studies suggest that high doses of sulforaphane between 150-300 mg/kg of body weight may cause more serious symptoms, including:

• Increased sedation (relaxation or sleepiness)
• Decreased body temperature
• Impaired motor coordination
• Decreased skeletal muscle strength

Sulforaphane is a sulfur-rich compound commonly found in cruciferous vegetables. It has antioxidant and anti-inflammatory properties. Studies have linked sulforaphane to improved blood pressure, cholesterol levels, and fasting blood glucose.

You can get sulforaphane through diet or by taking a supplement. People interested in taking sulforaphane supplements should speak with their healthcare provider first to ensure it’s appropriate for their individualized needs.