When I was suffering from hormonal acne, the number one recommendation SkinTok kept giving me was azelaic acid. This "wonder" ingredient was everywhere and was celebrated for its soothing, breakout-reducing benefits and accessibility, versus prescription retinoids like tretinoin and adapalene. But the stuff never worked for me long-term, and only caused more sensitivity as I continued to use it.
Look, I'm not here to slate azelaic acid as an ingredient. I know plenty of acne sufferers who have experienced great success with the active and swear by it. But just like tretinoin, I don't think it works for everybody; I'm living proof. So when I heard about another ingredient that had similar benefits, without the irritation, I was all ears. Enter: dioic acid. This ingredient can work wonderfully for acne and post-breakout marks, and is gentle and non-drying. Here's what the experts want you to know...
What is dioic acid?
Dioic acid is an ingredient gaining traction for its ability to not only help with acne, but also post-acne dark spots. For this reason, it's a real up-and-comer and has been popping up in plenty of modern formulations from brands such as The Inkey List and Allies Of Skin.
As Dr. Aiza Jamil, Consultant Dermatologist at SK:N Clinics, explains, it's "a naturally derived lipid that helps regulate excess oil production, reduce inflammation and fade pigmentation." She continues: "It works by inhibiting enzymes involved in sebum production and melanin synthesis, making it excellent for both breakouts and uneven skin tone."
Dioic acid has a similar make-up to azelaic acid as they come from the same ingredient "family", but studies have suggested the former can treat skin in a gentle way that doesn't irritate, unlike other, similar ingredients.
How can dioic acid benefit skin?
As mentioned, dioic is a brilliant acid for break-out-prone skin. This is because it regulates sebum production and is antibacterial and anti-inflammatory.
But that's certainly not all it's good for. "It works by switching on certain receptors in your skin cells, which then triggers a cascade of helpful effects: it calms inflammation, regulates oil production, fights bacteria, and tackles pigmentation," explains Cosmetic Physician Dr Emmaline Ashley, who notes that it works brilliantly for anyone with pigmentation, dark spots and melasma—or just for anybody wishing to brighten and even out their skin tone.
"The way it works on dark spots is particularly clever," she adds. "It turns down melanin production at a genetic level (so less pigment gets made in the first place), and it also blocks the transfer of melanin to surrounding skin cells. It's basically hitting the pigmentation problem from two different angles."
How should you use it in your routine?
Experts agree that dioic acid is generally well-tolerated, meaning most can introduce it into their skincare routine without any problem. However, Dr Jamil notes that "those with very sensitive or compromised skin should introduce it slowly, as it can occasionally cause mild dryness or irritation."
Dr Ashley suggests applying it once a day, ideally in the evening. Over time, if your skin tolerates it, you can build up to twice daily, morning and night, and research suggests this can produce the best results. "Look for products with 1-2% dioic acid, which is the concentration with the strongest evidence behind it," she continues. "One thing to know is that this isn't an overnight fix. Studies show gradual improvement over 12 weeks, with noticeable results usually kicking in around week four."
Remember to always wear SPF alongside this acid, and in terms of complementary ingredients, Dr Jamil makes a case for niacinamide and gentle retinoids, but notes that it should be introduced gradually if you're already using multiple actives.
Is it a good alternative to azelaic acid?
In one word, yes, particularly for those like me who have struggled with irritation triggered by azelaic acid. "Dioic acid can be a good option for people who find azelaic acid too strong or too drying," explains Dr Jamil. "Both target pigmentation and breakouts, but dioic acid is often better tolerated while still delivering similar brightening and anti-inflammatory benefits."
The two have undeniable similarities, meaning they're effective at some of the same things. Dr Ashley describes dioic as azelaic acid's more refined cousin: "Azelaic acid is brilliant, but it can cause that initial stinging or tingling sensation that puts some people off. Dioic acid tends to be gentler while still delivering similar benefits. Some research even suggests it's more effective against acne bacteria than azelaic acid."
That said, she concludes by saying that azelaic acid has been around for a long time and has plenty of research to back it up. It's just about finding what's best for your skin.
