Is Azelaic Acid a Standalone Treatment or Does It Need Supplements?

Azelaic acid comes up often in discussions of dermatology and hair health, particularly around androgenetic alopecia and alopecia areata. The question that follows is whether the compound can act as a standalone treatment, or whether it is only useful combined with other agents. Answering that means separating what azelaic acid is known to do in the laboratory from what has actually been shown in people with hair loss.

What is Azelaic Acid and How Does It Work?

Azelaic acid is a dicarboxylic acid, meaning it is an organic compound containing two carboxyl functional groups. It occurs naturally in cereals such as wheat, barley and rye, although the material used in dermatological products is made synthetically. It is described in the dermatology literature as anti-inflammatory, antioxidant and antimicrobial, and it is an established treatment for acne and rosacea.

It is also reported to inhibit 5-alpha reductase, the enzyme that converts testosterone into dihydrotestosterone (DHT). That finding comes from laboratory work, not from people: Stamatiadis and colleagues (British Journal of Dermatology, 1988) measured 5-alpha reductase activity in human skin in vitro and found azelaic acid inhibited it, with inhibition detectable from 0.2 mmol/l and complete at 3 mmol/l. The authors themselves closed by saying that if the inhibition were confirmed in vivo, the combination could be useful against androgen-related skin conditions. That confirmation in living scalp has not been published, so the anti-DHT rationale for azelaic acid remains a laboratory result rather than a demonstrated clinical effect.

DHT is a hormone derived from testosterone that binds to receptors in hair follicles and is associated with a progressively shorter growth cycle and a smaller hair root. This process, known as follicular miniaturisation, produces progressively finer hair until the follicle stops producing a visible hair. Because azelaic acid inhibits 5-alpha reductase in the test tube, it has been proposed as a way to slow DHT-driven hair loss — a proposal, not a proven treatment.

Azelaic Acid Treatment: Monotherapy vs. Complementary Use

In dermatology, "monotherapy" refers to a treatment based on a single active ingredient, meaning one compound is responsible for the whole therapeutic effect. A "complementary treatment" means using an ingredient alongside others, either to reinforce the effect or to address a different part of the condition.

The question for azelaic acid is whether its effect on hair loss is strong enough to stand alone, or whether it only makes sense inside a wider formulation.

Is Azelaic Acid Effective as Monotherapy?

There is one published randomised trial of azelaic acid used on its own. Thanomkitti and colleagues (Siriraj Medical Journal, 2023) randomised 26 women with female pattern hair loss, Ludwig grade I or II, to either 5% azelaic acid solution or 2% minoxidil solution twice daily for six months, measuring hair density and hair shaft diameter at baseline and at 2, 4 and 6 months. Both groups improved significantly from their own baseline, and there was no statistically significant difference between the groups at any visit. Itching was the main side effect in both arms and was reported as mild. The authors conclude that 5% azelaic acid "might be an effective treatment for FPHL, comparable with 2% minoxidil", and propose it as an alternative where minoxidil cannot be used.

That result should not be over-read. Twenty-six patients is a very small study; there was no placebo or untreated arm, so the within-group improvement cannot be separated from time and measurement; and the comparator was 2% minoxidil in women, not the 5% strength. "No significant difference between two small groups" is not the same as "equally effective" — a study this size cannot detect a moderate difference either way. It is a promising first result awaiting replication in a larger trial.

Figures quoted online for azelaic acid in hair loss — a percentage of extra regrowth, a number of participants, a named journal and year — should be checked against the journal before being relied on. Several such figures circulate without a traceable source behind them.

The honest summary is that azelaic acid has a laboratory mechanism, one small randomised trial in women with no placebo group, and nothing comparable to the repeated large randomised trials behind minoxidil and finasteride.

Using Azelaic Acid Alongside Other Treatments

Because inhibiting DHT is only one part of reversing hair loss, azelaic acid is most often encountered as a secondary ingredient in combination topicals rather than as a treatment in its own right. Where a combination product is used, any benefit seen cannot be assigned to the azelaic acid rather than to the minoxidil, caffeine or other actives beside it, unless the study was designed to separate them.

In alopecia areata — an autoimmune disorder in which the immune system attacks hair follicles — azelaic acid has been suggested to help through its anti-inflammatory action, but there is little published study of this. The usual treatments remain topical and intralesional corticosteroids and, for more extensive disease, the JAK inhibitors approved for alopecia areata: baricitinib, ritlecitinib and deuruxolitinib. These are prescription tablets whose US labels carry a boxed warning for serious infections, death, cancer, major cardiovascular events and blood clots (Olumiant, Litfulo and Leqselvi prescribing information on DailyMed), so they are used only under specialist supervision. Tofacitinib is used in this setting off-label and is not an approved first-line option.

Azelaic Acid Products and Market Presentations

Azelaic acid is sold in several forms, both as a general dermatological product and in formulations aimed at the scalp: creams, lotions, serums and shampoos.

Concentrations generally range from about 5% to 15% depending on the intended use, and application formats include droppers, sprays and foams. In several countries the 15% gel is a prescription medicine for rosacea, so availability depends on where you are.

Anyone considering azelaic acid should distinguish between products that use it as the main active and those where it sits alongside other ingredients. Products discussed by community members include the following. The compositions below are as stated by each manufacturer; none of them has published trial evidence for hair growth.

The Ordinary Azelaic Acid Suspension 10%

Made by the Canadian company Deciem, this product is known for its minimal formulation and low price, and comes in a 30 ml tube. It is sold for acne and rosacea, and some users have tried it on the scalp for its effect on inflammation and sebum. No clinical study supports scalp use, and at 10% it is a skin-care strength rather than anything trialled for hair loss.

Sesderma Azelac Lotion

Sesderma is a long-established dermatological brand. Its Azelac lotion is supplied in a 100 ml spray bottle that is easy to apply to the scalp. The manufacturer lists azelaic acid and salicylic acid and positions it for oily and acne-prone skin; it is also used on the scalp for folliculitis and seborrhoeic dermatitis. The claimed concentrations are the company's own and are not independently verified here.

Foligain Hair Growth Treatment

Foligain markets scalp lotions aimed at androgenetic alopecia, sold in a 60 ml spray applicator. The company describes formulations built around minoxidil together with additional ingredients. Where a product contains minoxidil, the minoxidil is the component with trial evidence behind it; the additional ingredients are the manufacturer's claim, not a tested contribution.

DS Laboratories Revita Shampoo

DS Laboratories sells hair products built around ingredient-delivery technology. Revita shampoo comes in 205 ml and 925 ml bottles, with a formula the company lists as including azelaic acid, caffeine, biotin and amino acids, and describes as using encapsulation for progressive release. The formulation is marketed for hair growth and scalp inflammation, but published evidence for azelaic acid's contribution in a shampoo is limited.

User Experiences

Azelaic acid is discussed frequently in the hair loss community, with mixed opinions on whether it works alone. Many users report using it as an adjunct rather than as a sole treatment for regrowth. The prevailing community view is that its anti-DHT and anti-inflammatory properties are not enough to hold back androgenetic alopecia (AGA) by themselves.

Several users say azelaic acid is usually included in topical formulations alongside minoxidil or other anti-androgens rather than used on its own. Some report reduced scalp inflammation and better scalp condition without noticeable regrowth from azelaic acid alone. A few who tried it without any other treatment described a small reduction in shedding but no meaningful regrowth over time.

Others describe combining it with stronger DHT inhibitors such as finasteride or dutasteride before seeing change. Some suggest pairing it with microneedling or minoxidil; others argue its benefits stay theoretical unless a systemic or stronger topical treatment is also in use.

A few members mention using azelaic acid in their skincare routine for acne and noticing incidental scalp benefits such as less irritation and oiliness — while adding that this did not translate into substantial regrowth.

Community opinion generally lands on azelaic acid being a supplementary treatment rather than a primary one, most often alongside minoxidil or finasteride.

Conclusion

Azelaic acid is an interesting ingredient in the hair loss discussion because of the in-vitro evidence that it inhibits 5-alpha reductase, because it is a well-established and well-tolerated dermatological treatment for acne and rosacea, and because one small randomised trial found no significant difference between 5% azelaic acid and 2% minoxidil in women with female pattern hair loss. What is missing is scale: that trial had 26 participants and no placebo arm, and nothing else of its kind has been published, while minoxidil and finasteride have repeated large randomised trials behind them.

On present evidence, azelaic acid is best treated as a lightly supported addition rather than a replacement for a treatment with substantial trial evidence — though the 2023 trial suggests it may be worth discussing with a doctor where minoxidil is not tolerated or is contraindicated. Talk to a doctor, dermatologist or pharmacist before starting, stopping or combining azelaic acid with other hair loss treatments — particularly if you are pregnant or breastfeeding, if you already use a prescription topical, or if the product you are looking at is a prescription-strength 15% preparation.

References

The first two references below are the hair-related evidence discussed above. The remainder document azelaic acid's pharmacology and its established use in acne and pigmentation, and are not hair loss trials.

Thanomkitti, K., Pruksaeakanan, C., Subchookul, C., Charoenpipatsin, N., Triwongwaranat, D., Varothai, S., Thuangtong, R., & Chumnumrat, T. (2023). Efficacy and Safety of Topical 5% Azelaic Acid Solution Versus 2% Minoxidil Solution in the Treatment of Female Pattern Hair Loss. Siriraj Medical Journal, 75(12), 887–893. https://he02.tci-thaijo.org/index.php/sirirajmedj/article/view/266001

Stamatiadis, D., Bulteau-Portois, M. C., & Mowszowicz, I. (1988). Inhibition of 5 alpha-reductase activity in human skin by zinc and azelaic acid. British Journal of Dermatology, 119(5), 627–632. https://pubmed.ncbi.nlm.nih.gov/3207614/

Fitton, A., & Goa, K. L. (1991). Azelaic acid. A review of its pharmacological properties and therapeutic efficacy in acne and hyperpigmentary skin disorders. Drugs, 41(5), 780–798. https://pubmed.ncbi.nlm.nih.gov/1712709/

Lowe, N. J., et al. (1998). Azelaic acid and glycolic acid combination therapy for facial hyperpigmentation in darker-skinned patients: a comparative study with hydroquinone 4% cream. Clinical Therapeutics, 20(5), 945–959. https://pubmed.ncbi.nlm.nih.gov/9829447/

Thiboutot, D., et al. (2008). Versatility of azelaic acid 15% gel in treatment of inflammatory acne vulgaris. Journal of Drugs in Dermatology, 7(1 Suppl), s8–s13. https://pubmed.ncbi.nlm.nih.gov/18246693/

Draelos, Z. D., et al. (1998). Efficacy and safety of azelaic acid and glycolic acid combination therapy compared with tretinoin therapy for acne. Clinical Therapeutics, 20(6), 965–975. https://pubmed.ncbi.nlm.nih.gov/9737831/