Found in wheat, rye, barley, and several types of grass, azelaic acid is also found in trace amounts in human skin. Although the word ‘acid’ may sound a bit off-putting, it’s actually pretty mild and is used to treat a variety of dermatological conditions. Now, evidence suggests azelaic acid may have another potential use: male pattern hair loss.
What is azelaic acid?
Azelaic acid is an organic compound produced in a variety plants. It’s also produced from a yeast that lives on human skin, malassezia furfur, and so is present in small amounts here as well.
It has anti-inflammatory properties which can help alleviate a number of skin conditions – most notably acne (more on this later). Azelaic acid also has mild antibacterial properties, meaning it can help keep the skin clean.
Azelaic acid and male pattern hair loss
As well as possessing these anti-inflammatory and antibacterial properties, azelaic acid may also act as a 5 alpha-reductase inhibitor. This, as we’ll see, makes it a potentially effective hair loss treatment.
Androgenetic alopecia (male pattern hair loss) is primarily caused by the hormone dihydrotestosterone (DHT).
And DHT is formed when testosterone, the male hormone, interacts with 5 alpha-reductase.
So more 5 alpha-reductase = more DHT = more hair loss.
Of course, not everyone has hair follicles that are sensitive to DHT. Some men can have high levels of DHT and yet keep their Norwood 1 hair lines. However, if you’re not one of these lucky few, the higher your DHT levels, the quicker you’ll go bald.
5 alpha-reductase is the reason FDA approved hair loss treatment finasteride is so effective. It reduces levels throughout the body which, in turn, reduces DHT levels too. Unfortunately, this can cause unpleasant side effects in some people, as DHT does more than simply make hair fall out.
A topical 5 alpha-reductase inhibitor could mean the best of both worlds though: reduced DHT to the scalp without affecting levels elsewhere. So does this mean azelaic acid is the answer?
Azelaic acid and DHT
The main evidence supporting the claim that azelaic acid stops DHT is found in this in vitro study.
Researchers tested the effects of azelaic acid and zinc on 5 alpha-reductase activity. They found:
“When added at concentrations of 3 or 9 mmol/l, zinc was a potent inhibitor of 5 alpha-reductase activity. At high concentrations, zinc could completely inhibit the enzyme activity. Azelaic acid was also a potent inhibitor of 5 alpha-reductase; inhibition was detectable at concentrations as low as 0.2 mmol/l and was complete at 3 mmol/l. An additive effect of the two inhibitors was observed. Vitamin B6 potentiated the inhibitory effect of zinc, but not of azelaic acid, suggesting that two different mechanisms are involved. When the three substances were added together at very low concentrations which had been shown to be ineffective alone, 90% inhibition of 5 alpha-reductase activity was obtained. If this inhibition is confirmed in vivo, zinc sulphate combined with azelaic acid could be an effective agent in the treatment of androgen related pathology of human skin.”
This is a pretty exciting discovery! Complete inhibition of 5 alpha-reductase! In theory, this could make it a full on hair loss cure, completely stopping baldness in its tracks.
But before we get carried away, it’s important to point the elephant in the room.
This study was conducted in vitro. In other words, outside of a living organism.
So while this is certainly an interesting discovery that warrants further investigation, it’s not conclusive. It may be that, when used on live hair follicles, it has no effect whatsoever.
Nevertheless, the case for azelaic acid looks promising. Not only that, another compound – zinc sulphate – demonstrated great results too! But that’s a topic for another article.
Acne – in vivo evidence
OK, so we know azelaic acid inhibits DHT in vitro. Is there any evidence of its effects on living, breathing human beings?
Actually, yes – just not for hair loss.
As mentioned in a previous article, male pattern hair loss and acne are quite strongly related.
For example, both are caused by hormones, and both are commonly associated with inflammation in the surrounding area.
Hence why CB0301, a hair loss treatment currently in development, is being trialled for acne too. Spironolactone, sometimes prescribed to women as an acne treatment, is another example of a hair loss treatment that tackles both these conditions.
So, what’s this got to do with azelaic acid?
Well, in 2002, azelaic acid was approved by the FDA for the treatment of acne.
I know, I know: it’s hardly conclusive. But in the absence of an in vivo clinical trial of azelaic acid for hair loss, it’s another piece of the puzzle. It shows – at the very least – that azelaic acid has some positive effect on living humans.
We know that inflammation is a symptom of both acne and androgenetic alopecia. We also know that azelaic acid alleviates this symptom. Finally, we know that azelaic acid is an inhibitor of 5 alpha-reductase – at least in vitro.
The evidence is pretty compelling. If nothing else, this warrants further study into the effects of azelaic acid on hair loss.
As far as side effects go, azelaic acid is pretty safe.
The most commonly reported side effects are limited to the local area where it is applied, such as:
- Stinging, or burning sensation
There are some sporadic reports of other side effects – such as increased heart rate – but these are very rare.
Because of its safety, azelaic acid can be found in some over-the-counter beauty products. For concentrations greater than 10%, though, a prescription is required.
So, is azelaic acid for hair loss effective?
The evidence is pretty hard to ignore.
First, azelaic acid has anti-inflammatory properties – and we know that inflammation and male pattern hair loss are strongly linked. What’s more, many actually cite inflammation as the cause of hair loss, rather than just a symptom.
Before I took steps to control my own hair loss, for example, I remember having a constantly inflamed and itchy scalp. It may not be a causal link, but there is certainly a correlation between itchiness/inflammation and increased hair fall – at least in my own experience. Azelaic acid reduces this inflammation and stops the scalp from itching.
Second, we know that azelaic acid is an effective treatment for acne. Acne, like androgenetic alopecia, is strongly linked to DHT.
But most importantly, azelaic acid has been demonstrated to inhibit 5 alpha-reductase activity.
OK, these tests were in vitro, but this is pretty strong evidence nonetheless. Anything that inhibits 5 alpha-reductase will also inhibit DHT, which will stop hair loss.