Androgen is a generic term for male sex hormones. There are several androgens, but the ones implicated in acne are:
- Dehydroepiandrosterone (DHEA) and dehydroepiandrosterone sulfate (DHEAS)
- Testosterone (T)
- Dihydrotestosterone (DHT)
In the acne development process, DHEA, DHEAS, and androstenedione act primarily as precursors to testosterone and DHT. The skin contains all the necessary enzymes for converting these precursors to T and DHT, both of which stimulate skin cell growth and sebum production far more than the precursor hormones.
Acne doesn’t happen without androgens
Acne is classified as an androgen-dependent condition. And indeed, without androgen hormones the development of acne is not possible. People with androgen deficiency or dysfunctional androgen receptors don’t produce sebum or develop acne (source). Also, several other lines of evidence point to androgens as one of the causes behind acne.
One of the more interesting investigations is a 2000 Dutch study of transsexuals undergoing a sex change. The sex change process by definition involves interventions with sex hormones, and thus gives us a unique opportunity to see how these hormones affect acne.
Male to female transsexuals (M -> F) treated with estrogens and antiandrogens showed sharp drops in both testosterone and sebum levels. At the beginning of the study, six of the participants (29%) M -> F had acne, but after four months of treatment, acne had cleared in all these subjects.
The opposite happened in female to male transsexuals (F -> M). At the beginning of the study, only five (31%) of the F -> M participants had facial acne, but after four months of androgen treatment that figure shot to 15 (94%). Similarly, at the beginning, only three subjects (19%) had back acne, but after four months 14 (88%) had the condition. There was also a steady increase in sebum production in the F-M group.
A European study from 2014 showed that acne scores increased by 375% in female -> male transsexuals who received male sex hormones. In contrast, acne completely disappeared in male -> female transsexuals who received androgen-reducing treatments.
Other similar situations include bodybuilders abusing anabolic steroids (often testosterone or one of the precursors) or drug interventions with steroids. About 50% of bodybuilders who take steroids get acne (source).
Tumors in the adrenals, ovaries, or testes sometimes lead to increased androgen production, and such tumors are known to increase the prevalence of acne (source).
Development of prepubertal acne has also been linked to androgens. A 2013 study on baby acne found that increased sebum production and acne correlates with temporary increases in androgens, namely DHEAS and testosterone. An older study on children aged between 5 – 10 years found that sebum production correlates positively with various androgens, especially the testosterone precursors that the skin can convert to testosterone and further to DHT.
Another study that followed 4th and 5th-grade girls for five years found that the girls who developed severe acne during the study had significantly higher DHEAS levels and earlier onset of menarche (first menstrual cycle), whereas the girls who had only mild acne got their periods up to two years later. Those with severe acne also had somewhat higher levels of testosterone and free testosterone, but no difference was found in estradiol or progesterone.
Estrogen seems to have the opposite effect. When volunteer male participants were given small amounts of estrogens over six weeks their sebum production levels dropped by 50%, but when testosterone was given at the same time, it negated the effect of estrogens (source). Studies on women have also shown estrogens suppress sebum production. Similarly, birth control pills work for acne because of their anti-androgenic effect (source).
Androgens can also explain why rates of acne decline with age. Secretion of DHEAS decreases progressively from the age of 30 to less than 50% of its maximal value by the age of 60, and this may explain why acne is rare in older people.
Finally, androgens explain why acne so often plagues facial skin but doesn’t affect other areas. The enzyme responsible for converting testosterone to DHT is 5 alpha-reductase (5AR). The activity of this enzyme varies between skin sites. It’s been shown to be the most active in the acne-prone facial skin, which leads to increased levels of testosterone, and more importantly, DHT in the area (source). Cell culture studies have shown that DHT is a 5 to 10 times more potent stimulator than testosterone. Testosterone itself is 5 to 10 times more potent than the precursor hormones. Increased levels of these hormones lead to faster skin cell growth, increased sebum production, and ultimately acne.
Do people with acne have too high androgen levels?
There’s no doubt that androgens play a critical role in acne, but that’s not the whole story. It’s too simplistic to say that people with acne have higher than normal androgen levels – because in most cases women with acne don’t have obvious androgen abnormalities. In fact, a 2000 study showed that severity of acne in women doesn’t depend on blood androgen levels.
I read over a dozen studies looking at hormone levels in women with acne. Most show minor abnormalities. The most consistent finding was that women with acne have higher levels of DHEA than women without acne. If you recall, DHEA is a precursor hormone to testosterone and DHT, and the skin has everything it needs to convert DHEA into T and DHT.
In 2000 Swedish researchers gave nine women who suffered from Adrenal failure (Addison’s disease) DHEA supplements. 7 of the 9 women developed acne, which disappeared when the supplementation stopped (source).
Anywhere from 15 to 40% of women with ‘resistant’ adult acne have more serious androgen abnormalities. That is to say, these women clearly have higher than normal androgen levels. They may also suffer from hirsutism, PCOS, or other adrenal-related problems.
The situation is a bit different in men. Far fewer studies have looked at hormone levels in men as compared to women with acne. There’s no clear evidence that men with acne have abnormally high androgen levels.
The skin is a hormonally active organ
We can explain this disparity (the role of androgens in acne yet normal androgen levels) in two ways. The skin is a hormonally active organ, and as we discussed earlier, it can convert the various precursor hormones into testosterone and DHT. There’s some evidence that the enzymes responsible for such conversions are more active in acne patients (source, source).
Studies looking at androgen production in the skin also raise the possibility that the higher than normal androgen levels in acne are a result, rather than a cause, of acne. That is, acne-prone skin pumps androgens into the bloodstream, and this results in higher than normal androgen levels. This is supported by the observation that isotretinoin (Accutane) treatment reduces blood levels of DHT but has no effect on the levels of the precursor hormones.
Signs of elevated androgen levels
Before we move on to the other hormones, let’s go over the signs of elevated androgen levels (hyperandrogenism). Because they play such a profound role in acne, it’s helpful to understand the warning signs.
Hyperandrogenism can affect both men and women, but is more noticeable in women. Symptoms include:
- Excessive hair growth (hirsutism) on the face, chest, abdomen, and pelvic area
- Severe acne or sudden onset of acne
- Acne that doesn’t resolve with typical treatments
- Absence of or irregular menstrual period
- Muscle enlargement
- Deepening of a woman’s voice
- Reduced breast size and enlargement of the clitoris
- Insulin resistance
- Polycystic ovary syndrome (PCOS)
If you notice any of these signs, please talk to your doctor about getting your hormone levels tested.