Azelaic Acid Explained (40 Studies): EVERYTHING You Need To Know

by | Last updated Apr 18, 2020 | 237 comments

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Azelaic Acid, a.k.a “The Unsung Hero.” It wasn’t until a couple years ago that people even started noticing this wonderful ingredient! Now everybody and their mom be like that fish from Spongebob…..

“Hey all you people! Hey all you people! Hey all you people won’t you listen to me? I just found an acid! No ordinary acid! An acid filled with beautifying property!”

azelaic acid spongebob

Search Azelaic Acid on Amazon

Anyhow…. let’s summarize all the science on Azelaic Acid in an easy comprehensive manner! As always, we’ll reviewing every major study done on it, as well as giving product recommendations at the end so we can replicate those studies at home. 😉

Here’s a table of contents in case you want to skip ahead to a section!

What is Azelaic Acid?

For you natural skincare enthusiasts you’ll be happy to hear it’s a naturally occurring compound found in whole grains, that is also produced by the skin’s microbiome (i.e. the healthy bacteria and yeast that live on our skin). (12)

It’s pH-dependent meaning it has to have the right level of acidity to work. Ideally a product containing azelaic acid will be formulated with a pH of 4.9, which is approximately the same pH of healthy human skin. Any lower and the product won’t be as effective. (3)

Related reading: Why the pH of Skin and Products Are Crucially Important

It’s generally used to treat acne, rosacea, and melasma though one study also found it’s effective against psoriasis too. (4)

What Are the Benefits of Azelaic Acid?

Be prepared for a massive wall of oncoming text explaining its badassery! This acid has been studied extensively and the benefits are plentiful.

When I first discovered it 3 years ago I felt like I found a goldmine no one knew about it. And as you can clearly tell, I stock up and have gone through several tubes of this stuff… ¯\_(ツ)_/¯

15% finacea gel

See Azelaic Acid on Amazon

Azelaic Acid Treats Acne VERY Effectively!

Let me start off by saying that if you’re using Benzoyl Peroxide to treat your acne, you should really consider opting out for azelaic acid instead.

Don’t get me wrong, Benzoyl Peroxide is a fantastic active ingredient and what kept me clear for many many years, but it has the tendency to be overly irritating and can cause some unwanted side effects longterm.

Let’s start our investigation by comparing azelaic acid to other popular acne medications.

  • Azelaic Acid vs. Benzoyl Peroxide.

How does azelaic acid compare against benzoyl peroxide? Pretty damn well. In fact, almost identically. In one study involving 580 people, subjects were either given 15% Azelaic Acid, 5% Benzoyl Peroxide, or 1% Clindamycin (an antibiotic). They were told to apply whatever they got every day for 4 months.

The results….

Clindamycin sucked balls (can you tell I’m not a fan of topical antibiotics?), and azelaic acid proved to be as effective as benzoyl peroxide. Overall, it reduced acne by about 70% on average without the side effects benzoyl peroxide had. (5)

  • Azelaic Acid vs. Tretinoin (Retin-A).

Once again azelaic acid compares almost identically. A 6 month study involving 289 people found that 20% Azelaic Acid cream and 0.05% Tretinoin were “equally effective” against acne. Very similarly to the Benzoyl Peroxide study, the Azelaic Acid cream was better tolerated and didn’t cause the side effects seen with Tretinoin. (6)

Studies showing the effectiveness of azelaic acid as an acne treatment, particularly against Benzoyl Peroxide, Tretinoin (Retin-A), and antibiotics have been replicated time and time again, the first as early as 1982. (789101112) One study even found azelaic acid was effective against adult acne when other treatments were not. (13)

UPDATE 4/19/19: more recent studies have shown the same thing, and it’s becoming increasingly prescribed for adult female acne. (41, 42, 43)

What I find particularly appealing about azelaic acid is that it’s great for inflammatory acne, or the big and painful “under the skin” pimples. To this day I use azelaic acid to spot treat any inflammatory lesions I might get.

Unfortunately many acne treatments like retinoids (e.g. differin a.k.a. adapalene) function as preventative measures because they target comedonal acne. In other words, they stop your pores from getting clogged which eventually reduces acne longterm, but it doesn’t do much for the big cystic pimples that are already there — azelaic acid does!

And I saved the best for last….

  • Azelaic Acid vs. effin’ ACCUTANE!

I started fan-girling so hard when I read this study! 😀 This clinical trial involved 85 participants with severe acne who were either given Accutane or 20% Azelaic Acid cream to be used with Minocycline (another lame antibiotic).

After 6 months the Azelaic Acid-antibiotic patients were 100% cleared of cystic acne! They also saw an 88% reduction in whiteheads and papules, and 70% reduction in clogged pores. Pretty unbelievable, if you ask me.

Accutane patients also saw 100% clearing in their cystic acne, and an increased 97% reduction in whiteheads and papules, and 83% in clogged pores. So, overall the Azelaic Acid-antibiotic group didn’t beat Accutane but did comparatively well.

Do note, this is Accutane we’re talking about here: the most powerful acne medication in the world! To do well against it is no small feat. The researchers who conducted this study agreed, and concluded that Azelaic Acid is a highly effective treatment for severe forms of acne, and considered it a valuable alternative to Accutane with fewer risks and better tolerability. (14)

  • How does Azelaic Acid work to treat Acne?

Azelaic Acid is antibacterial, anti-inflammatory, and anti-keratinizing (meaning it prevents a build-up of dead skin, which could in turn prevent clogged pores that cause breakouts). (15) If you want to learn more or see a visual of what the keratinization process looks like, watch this video.

Unlike Accutane, it doesn’t change how much sebum your skin produces but decreases the free fatty acid content in skin making it an inhospitable environment for bacterial and fungal overgrowth.

UPDATE 4/11/17: this also means it’s an effective treatment for “fungal acne,” or the skin conditions associated with malassezia like seborrheic dermatitis, pityrosporum folliculitis, dandruff, eczema, and psoriasis. The surface of skin that has been exposed to pathogenic malassezia is abnormally high in free fatty acids.

Source: The Role of Sebaceous Gland Activity and Scalp Microfloral Metabolism in the Etiology of Seborrheic Dermatitis and Dandruff. (41)

One of the mechanisms by which anti-fungals work against all the skin conditions mentioned above, is by regulating the free fatty acid content of skin. Azelaic acid has been shown to do exactly that. In fact, one study found that the levels of free fatty acids were reduced from 15.9% to 10.5%, after 1 month of using azelaic acid. (42)

Azelaic acid also starts accumulating in the follicle after just one application to concentrations high enough to inhibit protein synthesis by Propionibacterium acnes (the bacteria that causes acne) and Staphylococcus epidermidis. (16171819)

I know that sounds confusing, but think of it like this: a zombie apocalypse strikes and suddenly there’s no food available. Acne is a starving person, and Azelaic Acid is the farmer. Only the farmer tells the starving person to piss off and they promptly die.

Okay, that was a terrible analogy…. But you get the point! Essentially, azelaic acid creates an inhospitable environment that starves acne and malassezia-induced skin conditions to death.

Related reading: Pityrosporum (Malassezia) Folliculitis Treatment: How to Kick Fungal Acne’s Ass

Azelaic Acid Treats Rosacea.

  • What is Rosacea?

For the uninitiated, rosacea is a chronic skin condition characterized by erythema, or dilated capillaries (small blood vessels) that give an overall appearance of redness. There are four types of Rosacea (20) but the main two are subtype 1, and subtype 2. (21)

Subtype 1 is strictly limited to superficial facial redness, and often used interchangeably with “couperose skin.” Subtype 2 is known as papulopustular rosacea, and as the name implies includes papules and pustules (i.e. pimples and whiteheads) in addition to the facial redness.

Here are some photos of what that looks like.

  • Studies.

Despite how effective Azelaic Acid is against acne, the FDA has approved it as a treatment for Rosacea. In one study, 15% Azelaic gel was shown to control papulopustular rosacea over a period of 6 months by significantly decreasing erythema and inflamed lesions. (22)

Using antibiotics in conjunction with 15% Azelaic Acid gel has been shown to increase the effectiveness of its treatment against papulopustular rosacea. (2324).

I’d explain to you how it works against Rosacea, but then I’d have to kill you. Just kidding…..

Truth is, scientist don’t really know yet, but suspect it has something to do with its antimicrobial, antioxidant, and anti-inflammatory properties (no sh*t :p). (25)

Azelaic Acid Treats Hyperpigmentation and Melasma

  • What is Melasma?

Really quickly — melasma is a skin condition caused by an overproduction of melanin resulting in brown discolorations on the skin, and looks very characteristically like hyperpigmentation. (26) This condition is worsened through sun exposure. All the more reason you should be using sunscreen! Yes, I’m looking at YOU ma’am and / or sir.

  • Azelaic Acid vs. Hydroquinone?

In case you didn’t know, hydroquinone is a standard treatment for hyperpigmentation and melasma that works by inhibiting melanin production. It can be found over the counter up to 2%. Anything higher requires a doctor’s prescription.

There has been some controversy in the past regarding hydroquinone’s longterm safety, namely a 1991 study showing the possibility of it causing tumor growth in mice. (27) But there were a couple problems with this study; for example, mice were fed 0.8% hydroquinone rather than applying it topically.

Despite this, hydroquinone has been banned in South Africa, Japan, Australia, and the European Union. (28) There are some skincare experts and companies that disagree with this assessment, particularly Paula’s Choice and FutureDerm. But I’ll let you make up your mind on this.

However, if you wanna avoid the controversy altogether use Azelaic Acid! Some studies have shown it is more effective than 4% Hydroquinone in treating hyperpigmentation without the unwanted side effects. (2930)

One of the largest studies done was 24 weeks long, involved 329 women and found there were “no significant treatment differences” between the two. Better yet, azelaic acid had no severe side effects like exogenous ochronosis or allergic sensitization, which are rare but possible outcomes of prolonged hydroquinone use. (31)

Azelaic Acid is Good For Hair Growth.

The combination of zinc sulphate and azelaic acid has been shown to inhibit DHT, which makes it an effective treatment for hair loss. (32) This is why you’ll often see variations of Rogaine (Minoxidil) products containing azelaic acid.

  • Wait, I heard Azelaic Acid causes hair loss?

I’ve seen a few people assert this, but it isn’t entirely true and often results from a misunderstanding behind the mechanisms of hair loss. Let me explain.

Dihydrotestosterone (DHT) is responsible for androgenetic alopecia (better known as male or female pattern baldness). However, that same hormone is what causes facial hair growth in men. In other words, the hormone responsible for balding is the same hormone that causes men to grow beards.

This is why you’ll often see heavily bearded men that are bald. If you haven’t noticed that yet, have fun! 😉

  • The takeaway.

Azelaic acid is good for hair loss on the head, but can cause thinning of the beard. Even still, the thinning of facial hair would be very mild and unnoticeable to most people. As far as I know, there has only been one study documenting this and it was a rare exception. (33)

So ladies…. if your concerned about growing a beard it won’t hurt to use some azelaic acid. :p

Summary of the all the benefits.

Azelaic Acid is a highly effective acne treatment comparable to Benzoyl Peroxide, Tretinoin, and even Accutane. It also treats rosacea, melasma, and hyperpigmentation.

It has antibacterial, antioxidant, and anti-keratinizing properties. It prevents dead skin build up, unclogs pores, reduces redness, and most importantly does all this gently without major side effects! Azelaic acid may also be effective for treating hair loss.

Side Effects.

As you’ve probably gathered by now, there really aren’t any major ones. That’s what makes Azelaic Acid so great and versatile. It has numerous functions and treats many skin conditions without the irritation that goes hand in hand with other topical prescriptions and ingredients.

To summarize some of the main points in case you missed them: azelaic acid is associated with very little risk, is non-toxic, or teratogenic (meaning it may cause birth defects. See Accutane). It has excellent tolerability, doesn’t induce bacterial resistance, or photosensitivity (in other words, increasing the adverse effects of sun exposure). (3435)

When there are side effects they are very mild in nature and include stinging or burning upon application, and skin dryness. (36) Despite this, Azelaic acid doesn’t actually damage the skin barrier or cause transepidermal water loss (TEWL), which is just a fancy way of saying your skin losing moisture. (37)

How to Use Azelaic Acid and Tips.

Use about a fingertip’s worth of Azelaic Acid for the whole face after cleansing. If you find you are experiencing some irritation from it, try buffering it by applying your moisturizer first. This won’t decrease its effectiveness and is a good way of avoiding unnecessary irritation.

Remember to introduce it slowly and patch test first. More isn’t necessarily better. One study found that applying 20% Azelaic Acid cream once daily was just as effective as applying it two times a day after three months. (38)

If you can, opt out for 15% Azelaic Acid gel instead of cream. The gel has a lower lipid concentration requiring less emulsifiers and unnecessary ingredients that could potentially irritate the skin.

Another benefit of using the gel version is increased penetration. One study involving mice showed it had an 8-fold increase in delivery versus the cream version. (39) In short, the gel is more potent and less irritating.

When will I see results?

Pretty quickly. In a year long study involving 1,200 patients who used 15% Azelaic Acid gel, 81.9% of dermatologist noticed an improvement in acne after 35 days, and that number rose to 93.9% after 73 days. Almost 80% of patients said they were “very satisfied” with their treatment at the end of the study. (40)

Where can I find Azelaic Acid?

Azelaic acid is a prescription drug so it may be a little hard to locate especially if you don’t have a dermatologist. Hoping I don’t get in trouble for saying this, but you can find it on the bay of e…. if you catch my drift.

There are two main brands sold, namely 20% skinoren cream and 15% finacea gel. Do note that the name skinoren and finacea are used interchangeably: they are the same brand. The only thing that matters is what variation you prefer (cream or gel). If you live in the U.S. it might take a while to receive because it ships overseas.

UPDATE 5/15/2017: It appears that finacea/skinoren azelaic acid is only available on Ebay sometimes. :/

If you don’t like the idea of ordering a prescription drug online, or would rather not wait for long shipping times, there are two AzA products on Amazon. GIGI Bioplasma’s 15% Azelaic Cream, and Ecological Formulas Melazepam Cream which contains 20% Azelaic Acid. There is a third AzA product listed, but it doesn’t have the proper pH to work so don’t waste your time buying it.

UPDATE 10/26/18: Paula’s Choice 10% Azelaic Acid Booster is another option!

UPDATE 11/18/19: Azclear Action Medicated Lotion is another option with a minimal ingredient list, and 100% safe for those with fungal acne! 🙂

Alrighty, that does it folks. Have a lovely day!



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