Diindolylmethane, or DIM for short, is a natural compound that’s found in copious quantities in cruciferous vegetables like broccoli, kale, Brussel sprouts, and bok choy.
It’s found commonly in superfood green drinks, too.
It’s widely reputed as a strong anti-cancer agent that can also be used to reduce inflammation and detox your body thanks to the biological activity of DIM.
If these benefits are what you are looking for, our research team has ranked the ten best DIM supplements on the market according to purity and efficacy. Rad on for our rankings.
Last updated: January 5, 2023
Post workout supplements considered: 25
Hours of research: 40
Experts reviewed: 9
Scientific papers referenced: 17
1. Nutricost DIM
Nutricost delivers a DIM supplement with a dosage of 300 mg per capsule. It’s also got 5 mg of BioPerine, a proprietary black pepper extract that’s included in many higher-quality supplements for its reputed ability to boost absorption and bioavailability.
The capsules are vegetarian-friendly, and though there are a couple of extra binders included, it’s still a solid pick for a DIM supplement.
2. Zhou DIM Active
Zhou attempts to rectify one of the recurrent limitations with compounds isolated from healthy foods—when you take just one chemical out of a healthy food, you lose some of the synergy between the other compounds found in the food.
Zhou’s solution is to provide DIM (at a strong dose of 250 mg) alongside broccoli seed extract, vitamin C, and vitamin E.
The hope here is that the combined action of these ingredients will result in better outcomes than just consuming DIM by itself. This is sound reasoning, but clinical studies do tend to look at DIM in isolation, so whether you want to go with this supplement depends on your supplementation philosophy.
If you want DIM alongside the other nutrients in cruciferous vegetables, this supplement is definitely the way to go.
3. SMNutrition DIM
SMNutrition has a good dose of DIM with 200 mg of DIM plus 2.5 mg of BioPerine per capsule. BioPerine has been shown to increase the bioavailability of DIM for better absorption.
The capsules themselves are vegetable cellulose derived, which allows some pretty simple supplement design (the only other ingredient is organic rice concentrate), which make this supplement a go ahead for vegetarians.
4. aSquared Nutrition DIM
aSquared Nutrition is a solid source of DIM if you are looking for a supplement that has a low dose and no additional ingredients.
It has 100 mg of DIM per capsule, and no unnecessary ingredients—just gelatin for the capsule and rice flour to fill out the rest of the space inside the capsule.
5. Source Naturals DIM
Source Naturals DIM is a formulation specifically made to support breast health. Its DIM dosage is low, at 100 mg per capsule, but it also provides lecithin from soybeans to support estrogen function and BioPerine for superior bioavailability and vitamin E for added antioxidant power.
It’s a good choice for women looking to optimize breast health, but for all-around DIM versatility, it’s not the best.
6. DrFormulas DIM
DrFormulas is a very popular DIM supplement that includes BioPerine for superior absorption and delivers 100 mg of DIM per capsule.
This dosage is lower than the most effective doses found in clinical trials, so you’ll likely be taking at least two capsules twice per day.
In addition, the supplement design isn’t very clean; there’s a lot of extra binders and excipients included that hurt the product’s purity.
7. Purest Vantage DIM
Purest Vantage DIM is a supplement geared specifically for hormonal applications: while it includes BioPerine like many of its competitors, it also uses 600 IU of vitamin D (which is technically a hormone) and dong quai, a Chinese herbal extract with hormone-modulating properties.
This makes it possibly more useful for hormonal conditions, but less versatile than some of its competitors without these additional ingredients. At 250 mg per capsule, the DIM content is still solid.
8. Bulksupplements DIM
While Bulksupplements is always a good choice for highly pure supplements, in the case of DIM, it’s only a good call for a very small subset of people.
Because DIM’s optimal dosage is so small, you’ll need a milligram-accurate scale to measure out the right dosage.
So, unless you are planning on making a special blend of DIM and other supplements, or you need to mix DIM into smoothies or shakes, you should probably opt for a capsule based DIM supplement. If you don’t fit into these categories, though, Bulksupplements is the way to go.
9. Nature’s Way DIM-plus Estrogen Metabolism
Nature’s Way has a DIM formulation that is specially designed for processing estrogen. This makes it well-suited for women who use DIM for treating premenstrual syndrome, and possibly for other estrogen-related issues.
However, it does hamper its use for the wide range of other uses that DIM is known for. The actual DIM dosage is fairly low, though it is paired with a small amount of vegetable isolates from spinach, broccoli, and cabbage.
This pins Nature’s Way DIM-plus Estrogen Metabolism into a fairly niche use category, making it difficult to recommend for most people.
10. Nutrissence DIM
Nutrissence DIM provides a modest dose of DIM (100 mg per capsule), which is nice if you know you want a lower dose. However, beyond the dose, it doesn’t really distinguish itself from the other competitors on the market, which means it ends up lower in the rankings.
Best DIM overall: Nutricost DIM
Nutricost DIM is high-potency and pure. It boasts an industry-leading 300 mg of DIM per capsule and 5 mg of BioPerine for maximum absorption. If you need a powerful, all-purpose DIM supplement, Nutricost is the way to go.
Best DIM for men: Nutricost DIM
Maintaining high levels of DIM can help support your body’s free testosterone levels. Nutricost, with 300 mg of DIM per capsule, is perfectly suited for the task.
Best DIM for women: Zhou Nutrition DIM Active
Zhou Nutrition DIM Active includes broccoli extract alongside a high dose of DIM to support estrogen metabolism and turnover, making it perfect for women.
Best DIM for acne: SMNutrition DIM
Harnessing DIM’s anti-inflammatory and testosterone-modulating potential to reduce acne is an underutilized strategy for skin health. We recommend SMNutrition DIM for this purpose, thanks to its moderate dosage and high purity.
Best DIM for oxidative damage and inflammation: Zhou DIM Active
Zhou DIM Active pairs 250 mg of DIM with three synergistic antioxidants and anti-inflammatories: vitamin C, vitamin E, and broccoli seed extract. It’s your best option if you want to amplify DIM’s oxidation and inflammation-fighting capabilities.
Best DIM for bodybuilding: Nutricost DIM
Nutricost DIM’s high dose and superb purity makes it an easy add-on to any bodybuilding supplement stack. With a minimum of additional ingredients, you don’t have to worry about interactions with other supplements that you may be taking.
Who should buy DIM?
DIM is a supplement that is has a small number of highly specific and targeted applications. Like other antioxidant supplements, it excels at fighting inflammation and oxidative damage caused by free radicals. Here are a few specific populations that might consider a DIM supplement.
People who want to fight systemic inflammation. A huge range of health problems, from heart disease to cancer, are linked to chronic inflammation in the body. Antioxidants like DIM help combat this inflammation.
People who want the antioxidant benefits of kale and broccoli but can’t fit them into their diet. If you want higher antioxidant levels, leafy green vegetables like kale and broccoli are a great way to get them.
However, not everyone can get enough of these kinds of vegetables in their standard diet. For them, a DIM supplement might be a smart choice, since some research indicates that DIM could be the source of many of the health benefits of broccoli, kale, and other cruciferous vegetables.
People who want the potential longevity and anti-cancer benefits of DIM. People interested in longevity and cancer prevention are quite excited about DIM, since there is some suspicion that this molecule is part of why green leafy vegetables increase lifespan and decrease cancer risk.
How we ranked
To formulate our DIM rankings, our primary two criteria were dosage and efficacy. DIM’s action inside the body is fairly well-understood, at least in terms of its short-term effects and bioavailability, so we had a very narrow range of DIM doses in mind. Here’s how we applied these criteria to our candidates.
Only supplements with DIM dosages within the effective range. Doses below 100 mg are not particularly effective, and doses above 300 mg are poorly researched and are more likely to cause side effects, so we restricted the DIM products under consideration only to those that provided at least 100 but no more than 300 mg of pure DIM.
Focus on pure DIM. On the efficacy front, we eliminated any products whose primary focus wasn’t DIM. We allowed products with additional potentially useful ingredients, such as vitamin D or aids to bioavailability such as BioPerine (a proprietary black pepper extract).
Controlled bioavailability. While supplements that had ingredients to boost bioavailability can be useful, we noted that some research indicates that these agents can work too well at high doses, triggering side effects when the dose of DIM is 300 mg or more. To that end, we dropped products that had a high dose of DIM alongside aids for absorption.
Clean supplement design and helpful extras. Thereafter, we looked at the supplement design and the presence of any potential ingredients to boost efficacy. We found hormone modulators, like vitamin D, to be helpful, while binders or stabilizing agents meant that a particular DIM supplement scored lower in the final rankings.
With our rankings, which combine purity, efficacy, and clean supplement design, you can be sure you’re getting a high-quality product.
Q: How long does it take for DIM to work?
A: DIM’s efficacy appears to be pretty rapid. Once you take a dose of it, your body has fully absorbed the compound within two hours or so.
Furthermore, some studies (albeit small pilot studies) have found that biological effects attributable to DIM start appearing within two weeks of starting to take DIM. However, other studies have been a month or more, so count on it taking at least a few weeks for DIM to start working.
Q: Is DIM an estrogen blocker?
A: Interestingly, DIM’s ability to act against estrogen is one of the potential avenues that it may use to fight cancerous cells. DIM may be useful as an estrogen blocker, but it has only been studied in small experiments, typically in cancer patients.
Nevertheless, biological evidence indicates that it may act on estrogen receptors, which could hypothetically limit the effects of estrogen on your body. While many people would like to see more studies
Q: Is DIM bad for your thyroid?
A: In the context of thyroid function, DIM has only been researched as a potential way to slow the growth of thyroid tumors.
DIM’s mechanism of action has been linked to hormonal functions in the thyroid, but its action in people who have mild hypothyroid, or hyperthyroid, is unknown. So, because of limited research, we can’t say if DIM is necessarily good or bad for your thyroid.
Q: Is a DIM supplement good for men?
A: The utility of DIM as a supplement for men revolves around its potential ability to act as an estrogen blocker. While DIM does not appear to directly reduce the level of estrogen in your body, it does appear to act on receptors for estrogen.
While the findings that support this come only from very small studies, mostly on cancer patients, the implication is that DIM could lower the effective level of estrogen experienced by your body (as the action of some amount of the actual estrogen in your body would be “blocked” by DIM).
It should be emphasized that this effect is largely theoretical, though this has not stopped it from being adopted widely by men looking to boost their testosterone levels.
Q: When should you take a DIM supplement?
A: Based on data on the rate at which DIM is absorbed and excreted from your body, the current scientific data bets support taking DIM once or twice per day.
The timing of exactly when you take DIM is less important than the consistency with which you take it. You should take the same dose of DIM at the same time every day for best results.
That way, you’ll maintain a decent level of DIM in your body at all times, even taking into account the delayed absorption and and relatively fast excretion of DIM from your body.
Studies have not yet compared whether it’s better to take one individual dose of DIM per day or split it into two, but we do know that taking less than 100 mg of DIM at a time is not recommended, as doses lower than this do not generate detectable levels of DIM in the bloodstream.
DIM is a dietary compound found in several cruciferous vegetables that holds promise in preventing and treating certain cancers. This compound also plays a role in preventing bone loss and has anti-inflammatory properties.
Medical professionals have long stressed the link between eating a diet high in vegetables and the prevention of many types of cancers. Mounting evidence from clinical studies shows DIM’s strong positive impact on breast cancer, endometrial cancer, prostate cancer and other cancers.
Along another thread of potential applications, DIM looks like it may be a useful estrogen blocker. It does not directly lower the levels of estrogen in your body, but it might be able to block estrogen receptors in your body, which would reduce the effective level of estrogen that you are exposed to.
For BodyNutrition‘s #1 DIM recommendation, click here.