Here I’ll discuss other supplements you may have come across. Just to give you the straight dope on them. I don’t recommend taking these supplements – unless the other supplements haven’t worked for you.

Cinnamon

Cinnamon is another potentially useful supplement for hormonal-type acne. But compared to the other supplements we have discussed, there are far fewer studies on cinnamon, and the results are less impressive.

For example, two studies have looked at cinnamon for PCOS. One showed improvements in insulin resistance but not on testosterone levels. The other showed improvement in menstrual cycles but no change in insulin resistance or testosterone levels.

A 2012 systemic review of cinnamon for diabetes concluded the following:

Although some studies with cinnamon did not show any effects, the majority of studies performed did consistently show beneficial effects of cinnamon on multiple parameters, especially decreasing fasting and postprandial glucose levels and improving insulin sensitivity.

Rafehi, H., Ververis, K. & Karagiannis, T. C. Controversies surrounding the clinical potential of cinnamon for the management of diabetes. Diabetes Obes Metab 14, 493–9 (2012). https://onlinelibrary.wiley.com/doi/10.1111/j.1463-1326.2011.01538.x/abstract

In short, cinnamon might reduce insulin resistance and blood sugar levels, but so far studies have produced mixed results.

Given that studies haven’t provided convincing data to support cinnamon, it’s not a supplement I can recommend at this time. You’ll probably get much better results using some of the other supplements discussed in this section.

3,3′-Diindolylmethane (DIM)

Many natural health websites promote DIM as a surefire cure for hormonal acne. According to these websites, acne is caused by either estrogen dominance (too much estrogen in relation to progesterone) or toxic estrogens. DIM is said to detox toxic estrogens and to fix estrogen/progesterone imbalance, and many women swear it cured their hormonal acne.

There’s very little credible evidence to support either of those theories. Estrogen dominance is an ‘alternative medicine only’ condition and isn’t taken seriously by medical scientists. Whether ‘toxic’ estrogens (more accurately, an imbalance in the ratio of certain estrogen metabolites) causes cancer is currently debated in the scientific literature. Studies show DIM does affect the ratio of estrogen metabolites, but nobody knows yet whether this has any effect on cancer rates.

These theories aside, there may be other, more science-based, reasons why DIM supplements help acne. Unfortunately, all of this is based on in vitro (test tube) studies, and nobody can say whether the same things happen in humans taking DIM.

With the disclaimer disposed of, the test tube studies show:

• DIM can block androgen receptors and reduce the effect of testosterone and other male sex hormones. Scientists are currently studying whether DIM can treat prostate cancers (androgens feed many prostate cancers).
• DIM also has an estrogen-like activity in the body.One study showed it boosted, or amplified, the effect of estrogens in cells.
• DIM may also affect the mTor pathway. As discussed in the what causes acne section, mTor acts as sort of a master regulator of acne. It controls sebum production and skin cell growth. Test tube studies have shown DIM turns down (down regulates in medical speak) the mTor pathway, and, if this effect is confirmed in humans, this could explain why some women say it cleared their hormonal acne.

DIM has been tested in humans, but these studies mainly measure markers of cancer risk and as such aren’t relevant for acne patients.

It’s difficult to say whether DIM is helpful in acne as all the relevant data comes from test tube studies. DIM has serious potential as a cancer treatment/preventative, and there are several ongoing studies looking into this, but whether it also helps acne is yet unknown.

As such, it’s difficult to give any recommendations regarding DIM. The best I can say is to try it, if the other supplements haven’t worked for you.

Bioavailability

If you search for DIM supplements, no doubt you’ll come across with BioResponse DIM (BR DIM), a patented DIM formulation that claims to have a much higher bioavailability than the regular crystalline DIM. They claim that poor absorption of crystalline DIM makes it useless.

There’s very little data to support or refute these claims. BioResponse DIM manufacturers refer to a comparative absorption study done by the people who patented BR DIM – not exactly the most objective source. Unfortunately, that study was only published as a conference presentation and isn’t available anywhere. The only independent study showed that BR DIM resulted in about 50% increase in DIM blood levels as compared to crystalline DIM. Alas, this study was done on mice.

In the end, the best I can say is that BR DIM has been shown to have an effect on estrogen metabolism and prostate cancer indicators in humans, meaning it’s absorbed in sufficient dosages to have an effect. Whether crystalline DIM has the same effect remains to be seen. As such, going with BR DIM is the safer option.

Dosage

Most human studies used BR DIM in doses between 100 and 600 mg/day, given twice a day. Based on the papers I read, I would aim for 100 to 200 mg both in the morning and evening. This refers to BR DIM dosage, out of which about 25% is actual DIM.