All tests performed independently by
One of the largest and most respected lab testing companies, with over 100 locations around the world
Below are the sulforaphane levels produced by all top-selling sulforaphane supplements in the U.S., as measured independently by IEH Laboratories.
The numbers shown are the amount of sulforaphane yielded from a single serving. Scroll down to read more about what you see here, including an explanation of the ranges displayed for six of the products.
Click here to download a full PDF of actual lab reports showing these results.
The power of delayed-release capsules
BROQ now comes in natural plant-based delayed-release capsules, which means the contents are released and absorbed in the intestines rather than in the stomach.
In the stomach, the delicate myrosinase enzyme—which is needed in order for the body to absorb sulforaphane—is destroyed by acid. By contrast, the intestines have the same neutral pH as pure water, so the myrosinase stays fully intact.
Of all sulforaphane supplements on the market, only these 6 come in delayed-release capsules, enabling them to avoid the damaging effects of harsh stomach acid:
All other sulforaphane supplements sold in the US use immediate-release capsules, which expose the contents to stomach acid.
Products that use immediate-release capsules
All products that use immediate-release capsules were tested in two different liquids: water (pH 7.3) and acid (pH 1.5).
The result in water represents the amount of sulforaphane delivered without any degradation due to stomach acid.
The result in acid represents the amount of sulforaphane remaining after two hours exposed to stomach acid, assuming none was absorbed during that time.
The actual amount of sulforaphane you receive will be somewhere in between, since your body is likely to absorb some amount of sulforaphane before the stomach acid eradicates the myrosinase.
BIOAVAILABLE SULFORAPHANE PER SERVING
This is the expected amount of sulforaphane that will enter circulation in your body from a single serving of each product. Download full PDF of 3rd-party lab results here.
These are test results from IEH Laboratories, an independent 3rd-party lab. For delayed-release products, the quantity shown is the test result performed at pH 7.3. For immediate-release products, the quantity shown is the average of the result at pH 7.3 and the result at pH 1.5. In all cases, sulforaphane was measured after 2 hours of hydrolysis. Download a full PDF of 3rd-party lab results here.
ALL TEST RESULTS
this table shows the raw data from which the above levels were calculated.
* — Yellow shading indicates delayed-release products. For these, “Bioavailable Sulforaphane” is the test result in water (as this is the pH of the intestines, where these products are absorbed). Blue shading indicates immediate-release products. For these, “Bioavailable Sulforaphane” is the average of the test result in water and the test result in acid. Download the full PDF of 3rd-party lab results here.
Product Comparison FAQs
Can I download a full PDF of the lab tests for all products?
Yes, you can! 🙂
Why do some of the products tested have two results (one in acid + one in water), while others have only one result (in water)?
This is due to the difference between delayed-release and immediate-release supplements.
BROQ and 5 other sulforaphane supplements use delayed-release capsules.
All other sulforaphane supplements are immediate-release.
Delayed-release capsules release their contents in the intestines, where the pH is approximately 7.3—the same as water.
Immediate-release products are absorbed in the stomach, which is highly acidic (pH 1.5).
The acid in the stomach eradicates most or all of the delicate myrosinase enzyme that is needed to get sulforaphane into the bloodstream.
For all immediate-release products, two tests were performed: one in acid and one in water.
The actual amount of sulforaphane you receive from the product will be somewhere in between the two results (depending on how quickly the myrosinase is eliminated by the acid).
Why did you switch from having sulforaphane as an ingredient to having its precursors?
Three reasons:
(1) Sulforaphane is highly unstable, especially at high temperatures. The original formulation of BROQ lost 2% of its potency at room temperature every month. The new formulation (with precursors) does not.
(2) Due to the complexity and cost of stabilizing sulforaphane, delivering a consistent 25mg sulforaphane per serving would be prohibitive without using precursors.
(3) Stabilizing the sulforaphane in Original BROQ (and Prostaphane®) required a highly complex four-stage process which used solvents. The result was very far from the original natural sources. We consider it far preferable to use minimally processed ingredients which are closer to the versions found in nature.
What about the other products that have sulforaphane in them rather than the precursors?
There are only two.
The only one sold in the US is BrocElite®. It is an excellent product which delivers 1.9mg sulforaphane per serving. (BROQ delivers 25mg sulforaphane per serving.)
The other one is Prostaphane® (the same as Original BROQ). It delivers 19mg sulforaphane per serving—at maximum potency—but loses 2% monthly at room temperature (and more at higher temperatures).
Prostaphane® also has the other issues that sparked the change in formulation of BROQ: solvents, maltodextrin and magnesium stearate. (See discussion on the New vs Original BROQ Page.)
For sulforaphane, is it always more is better? Is there any downside to a higher level of sulforaphane?
Sulforaphane benefits are dose-dependent, meaning a larger amount tends to yield more benefits.
The most impressive studies showing significant benefits of sulforaphane used daily dosages of 30 to 70mg.
There is no known downside to taking larger amounts of sulforaphane, but it's always best to seek the advice of a physician.
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Wide Margin of Safety
Sulforaphane has been extensively studied in clinical settings, with doses up to 71 mg/day shown to be well-tolerated and safe. Even at higher levels, sulforaphane exhibits no signs of toxicity. Regulatory agencies and researchers consider its safety profile robust, with a broad range of acceptable daily dosages (Egner et al., 2011).
Efficient Metabolism and Elimination
The body metabolizes sulforaphane efficiently, converting it into bioactive compounds like sulforaphane-glutathione and sulforaphane-cysteine, which are then excreted. This rapid elimination reduces the risk of buildup, even when higher doses are consumed (Clarke et al., 2011).
No Significant Adverse Effects in Studies
Human trials involving sulforaphane supplements have consistently reported minimal to no adverse effects across a wide range of doses. This includes long-term studies, indicating that taking a larger daily amount is unlikely to cause harm (Bahadoran et al., 2020).
Adaptive Cellular Response
Sulforaphane works by activating the Nrf2 pathway, which boosts the body’s natural defenses. Importantly, this mechanism has an upper limit of activation, meaning excess sulforaphane is unlikely to overstimulate cellular processes or cause adverse reactions (Kensler et al., 2012).
Potential for Greater Benefits
While sulforaphane is effective at lower doses, studies suggest that higher doses may enhance its protective effects. This includes greater activation of antioxidant and detoxification pathways, as well as more pronounced anti-inflammatory benefits, without additional risk (Kim et al., 2013).
In summary, larger daily doses of sulforaphane pose no downside due to its excellent safety profile, efficient metabolism, and well-documented tolerability in clinical studies.
References
Bahadoran, Z., Mirmiran, P., & Azizi, F. (2020). Potential protective roles of broccoli sprouts and sulforaphane in human health: A review. Journal of Functional Foods, 64, 103617.
Clarke, J. D., Dashwood, R. H., & Ho, E. (2011). Multi-targeted prevention of cancer by sulforaphane. Cancer Letters, 269(2), 291–304.
Egner, P. A., Chen, J. G., Wang, J. B., Wu, Y., Sun, Y., Lu, W., ... & Kensler, T. W. (2011). Bioavailability of sulforaphane from two broccoli sprout beverages: Results of a short-term, cross-over clinical trial in Qidong, China. Cancer Prevention Research, 4(3), 384–395.
Kim, J., Kim, J., & Kang, H. (2013). Sulforaphane as a protective agent in detoxification. Molecular Nutrition & Food Research, 57(6), 1031–1042.
Kensler, T. W., Chen, J. G., Egner, P. A., Fahey, J. W., & Talalay, P. (2012). Translational strategies for cancer prevention in liver. Cancer Prevention Research, 5(5), 515–522.
Is delayed release better than immediate release? Why? And why didn’t Original BROQ use delayed release?
The advantage of delayed release capsules is that they release the contents in the intestines rather than the stomach, completely avoiding the damaging effects of harsh stomach acid.
See more discussion of this on the New BROQ vs Original BROQ Page.
Do I need to worry about the large dosage of sulforaphane causing digestive discomfort?
There should be close to zero risk that you will experience digestive discomfort, even taking multiple daily servings of New BROQ, because:
(1) It is absorbed in the intestines rather than the stomach. The source of Original BROQ's digestive discomfort was in the stomach.
(2) In all of our testing of New BROQ, we did not receive a single report of digestive discomfort.
(3) Some speculate that one (possibly quite significant) source of gastrointestinal effects of Original BROQ was the trace residuals of the solvents used in its manufacturing (although these were always at safe levels, well within FDA guidelines).