Azelaic acid does help with blackheads, though it works differently than you might expect. Rather than dissolving the oil and debris already trapped in your pores, it slows the overproduction of skin cells that clog them in the first place. Clinical trials show it reduces non-inflammatory acne lesions (the category that includes blackheads) significantly, with results comparable to retinoids for clearing clogged pores.
How Azelaic Acid Prevents Clogged Pores
Blackheads form when dead skin cells pile up inside a pore, mix with oil, and create a plug that oxidizes and turns dark at the surface. Azelaic acid targets this process at its root by slowing down the rapid turnover of skin cells lining your pores. It’s classified as an anti-keratinizing agent, meaning it reduces the overproduction and abnormal buildup of the protein-rich cells that form those plugs.
Specifically, azelaic acid interferes with how skin cells mature and harden. It delays the production of filaggrin, a key protein involved in the final stages of skin cell hardening, and reduces the structural components that make dead cells sticky and prone to clumping. It also inhibits the DNA and protein synthesis that drives excessive cell production inside the follicle. In one study, 8 to 12 weeks of twice-daily application of 20% azelaic acid cream led to significant reduction or normalization of the excess skin cell buildup both inside pores and on the surrounding skin surface. Importantly, the reduction in pore-clogging was comparable to what retinoids achieve, which are considered the gold standard for comedonal acne.
Azelaic acid also has a modest effect on oil production. A study measuring sebum levels before and after treatment with 20% azelaic acid found that oiliness on the forehead dropped from 195.5 to 162.7 (roughly a 17% decrease), with similar reductions on the cheeks. These effects persisted three months after treatment ended, suggesting it creates a lasting shift rather than just a temporary suppression.
What the Clinical Results Look Like
In a 16-week study using 15% azelaic acid gel, participants saw a 48% median reduction in total acne lesions by week 4 and a 98% reduction by week 16. While that study tracked all acne types, separate trials confirm that non-inflammatory lesions like blackheads respond well. Research on 10% azelaic acid gel found statistically significant decreases in non-inflammatory lesion counts by the end of the study period.
The American Academy of Dermatology includes azelaic acid in its acne management guidelines as a conditional recommendation, placing it alongside salicylic acid as a recognized treatment option. It’s not the most aggressive choice for blackheads, but it’s a proven one, particularly for people who need a gentler approach.
How It Compares to Salicylic Acid
If you’re choosing between azelaic acid and salicylic acid for blackheads, your skin type is the deciding factor. Salicylic acid is oil-soluble, so it penetrates into pores and dissolves the debris directly. This makes it particularly effective for oily skin with visible blackheads. Azelaic acid works more gradually by preventing the buildup from forming rather than clearing what’s already there.
For oily skin, salicylic acid is generally the stronger choice for blackheads. It cuts through excess sebum and exfoliates more aggressively. For dry or sensitive skin, azelaic acid has a clear advantage. Its exfoliating effects are gentler, and it doesn’t strip moisture the way salicylic acid can. Azelaic acid also brings anti-inflammatory and skin-brightening benefits that salicylic acid doesn’t, which matters if you’re dealing with dark spots alongside blackheads.
Which Concentration Works Best
Azelaic acid comes in three common concentrations: 10% (available over the counter), 15% (prescription gel), and 20% (prescription cream). The good news is that even the lower concentrations appear effective. Research found that 10% azelaic acid gel produced statistically significant reductions in non-inflammatory lesions, and one study concluded that 10% azelaic acid performs comparably to benzoyl peroxide for acne. Another found that combining 5% azelaic acid with an antibiotic gel matched the results of 20% azelaic acid with the same antibiotic.
That said, most clinical trials demonstrating the strongest results use 15% or 20% formulations. If you’re starting with an over-the-counter 10% product and not seeing results after a couple of months, a prescription-strength version may be worth discussing with a dermatologist. The 15% gel formulation is the most commonly studied in clinical settings and is typically applied twice daily to the full affected area, not as a spot treatment.
The Purging Phase
One thing that catches many people off guard is that azelaic acid can temporarily make blackheads worse before improving them. Because it speeds up skin cell turnover, congestion that was sitting deeper in your pores gets pushed to the surface faster than it normally would. This is called purging, and it’s a sign the product is working, not that it’s making your skin worse.
For most people, purging lasts 4 to 6 weeks, though it can stretch to 8 or even 12 weeks if you have significant congestion or slower skin turnover. Here’s a rough timeline of what to expect:
- Weeks 1 to 2: Increased breakouts appear as skin begins turning over faster.
- Weeks 3 to 4: Breakouts may peak as deeper congestion surfaces.
- Weeks 5 to 6: Noticeable improvement begins, with fewer new breakouts and smoother texture.
- Weeks 8 to 12: Significant clearing for most people. If your skin is still breaking out heavily past the 12-week mark, the product likely isn’t the right fit.
The temptation to quit during weeks 2 through 4 is strong. Give it at least 6 to 8 weeks before making a judgment call.
How to Use It for Blackheads
Apply azelaic acid twice daily to the full area where you get blackheads, not just on individual spots. Wash first with a gentle, non-stripping cleanser, let your skin dry, and then apply a thin layer. If you’re using it alongside other actives, apply azelaic acid after lighter, water-based products and before heavier creams or oils.
If twice-daily application causes irritation, starting with once a day (usually at night) and building up over a week or two is a reasonable approach. Azelaic acid is well tolerated by most skin types, including sensitive and rosacea-prone skin, but mild tingling or stinging during the first few applications is normal and typically fades as your skin adjusts.