Now, I'm going to preface this by saying that I have dabbled in progesterone myself (not for acne specifically, but for other health issues), and some of the literature out there for "low progesterone / estrogen dominance" makes sense to me, even though estrogen dominance is not recognized by mainstream medicine.

HOWEVER, there is very little scientific evidence out there showing that low progesterone = acne or that high estrogen = acne. Yes, some books and a lot of naturopaths say that it does. Yes, some people have anecdotally experienced clearance of acne from estrogen dominance protocols (and I applaud their success).

I've been bamboozled by it all a little myself, until you realize that most of these naturopaths basically claim that progesterone fixes every possible symptom of any health problem you could have.

So I'm writing this post to explore what literature is (or isn't) out there that actually supports "low progesterone / estrogen dominance = acne."

Basically...what is progesterone?

Progesterone is a precursor in the steroid hormone cascade. It can be converted to testosterone and estrogen as needed, among other things.

So, as progesterone is also a precursor to testosterone/estrogen, if your progesterone is too high, progesterone itself can potentially cause testosterone/estrogen hormonal imbalances down the steroid hormone path.

Similarly, though, if progesterone is too low, it can cause a number of deficiency problems because progesterone is needed to complete various pathways. Could possibly a deficiency of progesterone lead to a hormonal imbalance that causes acne? Yes, I suppose it could. However I couldn't find any studies showing that particular outcome.

What does progesterone do for the skin?

Let's first go through what all the hormones do for the skin.

Estrogen:

• Thins sebum secretions
• Reduces size and activity of sebaceous glands
• Increases activity of hyaluronidase (related to hyaluronic acid, related to skin moisture content)

As far as acne production goes, thinning sebum and reducing sebaceous activity is a HUGE positive.

Testosterone:

• Increase sizes and activity of sebaceous glands
• Increases rate of cell turnover in the basal layer which thickens the skin around the sebaceous duct

Increasing sebum production is bad when it comes to acne, and so is thickening the skin around the sebaceous duct because it makes a sebum plug -> acne more likely. If you've forgotten how that links together, see this image:

Progesterone

Okay, but what does progesterone do? The short answer is that the direct relationship between progesterone and the skin has not been studied much. The skin has progesterone receptors. Their action is mostly unknown.

It does seem to have some anti-inflammatory effects on the skin. Not necessarily directly related to acne, but conceivably could have an effect since acne involves inflammation:

- Progesterone regulates lipid peroxidation (free radical cell damage)

- Progesterone regulates lysosomal activity (sort of like garbage disposal for your cells)

Again, is that directly related to the sebum plug -> acne chain in the picture? No, but some anti-inflammatory action on the skin could still help.

- May temporarily reduce sebum secretion in females

There is evidence that anti-androgens may help in the treatment of acne vulgaris. We therefore performed a double-blind trial to assess the effect of topically applied progesterone on sebum excretion rate. Thirty-eight patients took part in the trial which was for 3 months. The preparation had no etfect in males. However, a signiticant reduction in sebum excretion rate was found in females, the etfect being maximal at the end of the second month. There was a significant loss of effect at the end of the third month and this was not related to deterioration of the progesterone preparation.

I got bad side effects on anti-androgens like spironolactone or saw palmetto. Does progesterone have anti-androgenic effects?

Natural progesterone (and SOME types of synthetic progestins) has a high affinity for 5 alpha reductase, which means that it competes for 5 alpha reductase with testosterone. Why is this a good thing? Because testosterone uses 5 alpha reductase to convert to dihydrotestosterone (DHT) which has been implicated as a potent factor in acne.

I really want to stress this point, because some who use progesterone claim that "reducing androgenic activity doesn't help my acne." BY USING PROGESTERONE you are exerting an anti-androgenic influence on your body!

Perhaps progesterone's particular mechanism worked well for you and spironolactone's didn't. But please realize that we are still attacking the same thing here, which is an ANDROGENIC problem -> acne.

Can HIGH progesterone cause acne?

We are talking about natural progesterone here. (Many synthetic progestins, have been shown over and over again to have androgenic activity.)

- Progesterone can increase sebaceous hyperplasia (at least in rats -- see Haskin's study)

- Progesterone as effective as testosterone in stimulating sebaceous glands (at least in the elderly -- see Smith's study)

- Progesterone CREATED acne in females

However, these studies have been countered by other studies (Strauss and Kligman) that say that natural progesterone is largely "sebaceous gland neutral." So the jury is still out on this one.

How does progesterone reduce estrogen?

>

PROGESTERONE has long been considered an antagonist of oestrogen action¹. The delicate balance and interactions between these ovarian hormones are essential for many reproductive functions. Early studies in chick oviducts and uteri of rats and mice have shown that the simultaneous administration of progesterone and oestrogen resulted in inhibition or modification of oestrogen-induced growth of these target organs^2“5. One possible mechanism by which progesterone could be antagonistic to oestrogen is by suppressing the quantity of cytoplasmic oestrogen receptor. It is generally held that the mechanism by which oestrogen, O, stimulates uterine growth depends on the binding of O to cytoplasmic receptors, R_c, to form R_CO complexes⁶. These R_CO complexes are translocated to nuclear sites where they probably stimulate nuclear events that cause the uterus to grow⁷. Translocation and nuclear accumulation of receptor“oestrogen complexes, R_nO, are accompanied by a concomitant decrease in the quantity of R_c (ref. 8). During the period when R_c is reduced, the uterus is insensitive to additional exogenous oestrogen⁹. Gradually R_c is replenished by processes which may involve reutilisation and/or resynthesis⁸. Work from our laboratory indicates that the mechanism of action of non-steroidal oestrogen antagonists resides in their inability to stimulate the replenishment of the cytoplasmic oestrogen receptor, R_c, thereby rendering oestrogen responsive tissues less sensitive to oestrogen^10,11. The possibility that progesterone might also act as an oestrogen antagonist by reducing the amount of oestrogen R_c has been suggested^12,13. In this report, we demonstrate that progesterone does decrease the quantity of oestrogen receptors by interfering with the replenishment of R_c and that this decrease results in a reduced sensitivity of uterine tissue to oestrogen.

Does high estrogen cause acne?

I could not find any studies linking high estrogen levels to acne. If anything, most research indicates that while excessively high estrogen has other side effects (such as weight gain), estrogen overall is extremely beneficial for acne.

Does lowering androgenic activity or raising estrogenic activity change the menstrual cycle, via spironolactone?

The reason spironolactone is indicated for messing with the menstrual cycle is, as far as research has shown, because of its PROGESTOGENIC effect. Not to get huffy on this, but people keep stating that "lowering androgenic activity" or "raising estrogen" changes the menstrual cycle, and then point to spironolactone as proof. It is the progestogenic activity that is most likely to blame (citation). Also think: you can have a progestin-only birth control pill. Why? Because progesterone is ultimately what controls the cycle.

Another point here, is that Finasteride, which has been often compared to spiro, is very powerful anti-androgen but does not have progestogenic effects. As such, Finasteride does not interfere with the menstrual cycle (citation). So again, it is not the testosterone or the estrogen that really messes with your periods, it is progesterone. This is also why some doctors recommend cycling spironolactone for patients who are very sensitive to the weak progestogenic effect.

Conclusion

So from my (admittedly limited) study...

High estrogen does not cause acne.

Low progesterone does not cause acne (at least not directly).

High progesterone can potentially cause acne.

Progestogenic effects are responsible for major menstrual cycle changes.

Androgens can cause acne.

Progesterone's anti-acne mechanism is primarily its anti-androgenic action.

If one is progesterone deficient, progesterone may potentially solve health problems (possibly including acne) via its general ability to create and regulate other hormones.

Thanks for this info! It's really helpful -- I've been confused and this cleared it up for me.

I see what you are saying, but sometimes anecdotal evidence is more potent than scientific research. If you think about it, acne treatments haven't progressed much since the 80s. They are targeting the same areas, with slightly different formulations with slightly less side effects to each treatment. Just because there is lack of scientific evidence to suggest that low progesterone (as well as high) and high estrogen (as well as too low) can cause acne, doesn't mean anything. Who will fund those studies anyway? Acne is very low on the list of diseases to treat anyway.

Estrogen/progesterone balancers work for some people, and do not work for others...this shows that not everyone's acne is caused by the same reasons. Vitex and DIM are the two primary herbs that come to mind when it comes to helping estrogen dominance, and they do not necessarily targed androgens. In my case, I had signs of HIGH androgens on vitex, yet clear skin. Scientifically impossible? Not according to my face. I'm going based on my experience and experiences of others on various boards when it comes to alternative treatments, in addition to reading whatever little I can find from medical journals and clinical studies. I think there is definitely insufficient evidence that progesterone and estrogen can/ cannot cause acne, so we shouldn't rule it out. I get what you are saying about progesterone being anti-adrogenic...that seems like a valid point, but I also think it lowers estrogen too. We also haven't mentioned other hormones like FSH, which I think can play a part in acne too. The ideal is to find a treatment that clears acne AND keeps cycles regular.... I think it's unnatural to mess up cycles (esp. if they are regular) for the sake of clear skin. There's a way to have both.

And again, going with my self as an example, my acne never responded to anti-adrogens alone and in fact anti-androgens gave me estrogen dominance symptoms. The reason why inositol is working for me is because it's not just suppressing testosterone. It increases progesterone and helps in so many other ways. Yes, higher progesterone can help lower androgens, but it also helps balance estrogen levels. We can't be 100% sure what it does to the body, and how each person will react to it. Hence, some women's skin gets worse on NPC, while for others it is very beneficial.

I also found that hormonal acne can be kept at bay without targeting androgens, e.g. by: antihistamines, paleo diet, digestive enzymes, boosting glutathione production, taking a whole food multivitamin, getting regular sun exposure, avoiding depression, limiting processed sugar/ regulating insulin, regular exercise, low histamine diet...etc. Each time I used a different approach, NOT targeting androgens directly, to recover and I never messed up my cycles in the process.

I don't think there's only one way to target acne, even if it is hormonal. I wish I had more scientific evidence to back this up, but my face clearing up after severe acne is proof enough for me.

But anyway, I think this discussion is very helpful even if I question some parts of it, because it might help women who are more receptive to natural treatments find an alternative route for treating their skin.

This is all very interesting. The endocrine system is super complicated and I don't think no one will ever completely understand how things work exactly. The reason progesterone may work for some and not for others may be that it reacts differently on everyones body. It might convert to testosterone and make acne worse. Or it might convert to estrogen and still leave you with low progesterone. Here's and interesting article about estrogen dominance:

http://www.womentowomen.com/hormonal-health/estrogen-dominance/

From what I've read I've got the impression that androgens are always on some level behind acne. I find it weird that one can have totally normal blood test results and still clear on spiro or other anti-androgens. This is all very confusing..