Azelaic Acid

What is the skin science behind azelaic acid?

Azelaic is anti-inflammatory, anti-microbial, as well as an inhibitor of pigmentation production. This is a naturally occurring by-product of wheat, barley and rye. This acid is also naturally produced by yeasts found on skin. The science behind this compound is as follows-

• Inhibitor of tyrosinase: This enzyme is responsible for melanin production. By reducing the activity of tyrosinase, Azelaic Acid can reduce the output of pigment. Hence its use in melasma & post inflammatory hyperpigmentation.
• Anti-inflammatory: This acid can modulate cytokines & other inflammatory mediators, hence its use in both acne & rosacea.
• Anti-bacterial: Decreases counts of C.acnes, the bacteria implicated in pimples, zits & acne cysts.
• Chemical exfoliation: This acid has weak, but demonstrable effects on keratin, namely it acts as a mild chemical exfoliant. This reduces build up within pores & can help reduce blackheads formation.

Can azelaic acid lighten skin?

Azelaic acid can decrease pigment production and is the treatment of choice for melasma as part of rotational therapy (refer to pages on how to treat melasma).

This acid can also reduce pigmentation due to sun exposure as well as freckles. It works as a tyrosinase inhibitor, meaning the mechanism of action is targeted at resolving increased pigmentation itself. This acid also acts as a keratolytic, meaning its secondary effect is increased turnover of skin cells, hence shedding excess pigment. 

Note: Azelaic acid is a weaker pigment inhibitor compared to hydroquinone, kojic acid & arbutin. Nevertheless, it plays an important part in rotational therapy for melasma. Azelaic acid is category A – hence my preferred pigment inhibitor in pregnancy.

How long does it take for azelaic acid to work?

It will take 4-8 weeks of consistent topical use of azelaic acid before you begin to see improvements, depending on the skin condition you are targeting. Azelaic acid works faster in calming down acne & rosacea (2-4 weeks), whilst it’s skin brightening role may take 6 to 8 weeks to be seen. 

In the context of melasma, azelaic acid is designed as a treatment to reduce rebound pigment. If you do get pigment reduction, that is a bonus.

How Does Azelaic Acid Compare to Alpha Hydroxy Acids or Salicylic Acid?

All three ingredients are keratolytics or chemical exfoliators however they do act differently. Although azelaic acid can exfoliate skin when formulated in a low pH vehicle, it is not as potent as say glycolic, lactic or salicylic acid. 

On the flip side, azelaic acid offers additional benefits that AHA and BHA ingredients don’t provide, especially when it comes to improving uneven skin texture & reducing skin inflammation. The solution? Use a stand-alone hydroxy acid, either as a wash or cream, followed by azelaic acid. Refer to the combination guide below.

How often should I use it for treating melasma?

Once to twice daily. We do prefer the following routine to reduce pigment-

AM: CE Ferulic acid + SPF

PM: Azelaic acid 10-20% 

Azelaic acid is useful as part of your maintenance therapy or rotational therapy. Be guided by your allocated clinician.

Can you use azelaic acid every day?

Yes, azelaic acid can be used up to twice a day. This acid is ideal for people who suffer from sensitive skin. Start with a 10% formulation, apply once daily then increase as tolerated. If you have any redness, skin irritation or dryness, reduce the amount & frequency of azelaic acid.

What are my recommended concentrations for azelaic acid?

Concentrations around 10-20% are best. This molecule has a very low irritation potential; however, it is not advisable to go above 20%. Azelaic acid is available without a prescription & is sold by most pharmacies. Our preferred brand is Azclear.

What brands do we recommend?

Azelaic acid brands include Azclear or Paula’s Choice. Azclear has a higher concentration of Azelaic acid (20%), compared to Paula’s Choice (10%). Azclear is more cost effective.

Why is azelaic acid the treatment of choice for melasma in pregnancy?

Azelaic acid is a naturally occurring compound & classed as Category A in pregnancy. It is safe in pregnancy or breastfeeding. Other safe pigment correctors in pregnancy include ascorbic acid, niacinamide, & botanicals.

Can azelaic acid be mixed with other skin care?

Even though the irritation potential of azelaic acid is low, it is best to start this topical on alternate nights, especially if you are using higher strength retinols, ascorbic acid, skin acids. Read below for a guide.

Can azelaic acid be used with retinol?

Azelaic acid may be used with retinol, however they are best applied with a 20-to-40-minute interval in-between applications. Alternatively, you can use azelaic acid in the morning & retinol at night.

Can azelaic acid be used with niacinamide?

Azelaic acid may be used alone or paired with other soothing and brightening ingredients like niacinamide, ascorbic acid, arbutin, & Kojic Acid. It generally can be combined with other products because azelaic acid is a stable molecule. The caveat is that the most stable form of azelaic acid comes as a gel formulation, hence it should be used in the same base as your other ingredients.

What is better for pigmentation, azelaic acid vs vitamin C?

Azelaic acid vs ascorbic acid studies have not been established. The outcome will vary depending on-

•     The concentration of each. Azelaic acid ranges between 10 to 20%, whilst vitamin C ranges between 5 to 20%. 
•     The tolerability of the patient. Vitamin C is far more irritating as it has a low pH. Patients with sensitive skin may not tolerate vitamin C.
•     Co-existing skin conditions such as acne, rosacea or an impaired skin barrier. In these cases, I would lean towards azelaic acid over ascorbic acid. 

In most cases I start patients off with azelaic acid in the evening, then add ascorbic acid in the mornings, starting 3-6 weeks after initiating the former.

What is better for pigmentation, azelaic acid vs hydroquinone?

Hydroquinone (at therapeutic concentrations) is far better than azelaic acid, however there are several stumbling blocks with hydroquinone- 

1.   HQ is harder to get as it is regulated in many countries. 
2.   Hydroquinone is harder to use as it has more skin irritation. 
3.   Hydroquinone has side effects such as exogenous ochronosis (darkening of pigmentation). 
4.   HQ cannot be used long term, whilst azelaic acid can. 
5.   Hydroquinone can’t be used in pregnancy. 
6.   Allergies to HQ, though rare, is more common than with azelaic acid. 
7.   Greenies & natural remedy skincare experts find it hard to understand the studies relating to HQ carcinogenic potential. 

The decision to use HQ rests on the call of your dermatologist or treating clinician. 

What does a sensible skin care routine with azelaic acid look like?

AM: Cleanser, Anti-oxidant (Ferulic acid, Vitamin C, E) , SPF, Make up

PM: Cleanser, +/- Toner, skin care actives (Azelaic acid, A,B, Skin Acids, or Pigment correctors).

Azelaic acid may be used alone or paired with other soothing and brightening ingredients like niacinamide,hydroxy acids or antioxidants. It generally can be combined with other products because azelaic acid is a stable molecule. Ideally used on alternate nights if you want to continue with vitamin As, Cs or pigmentation correctors, slowly increase azelaic acid application frequency as tolerated. 

Pigmentation fine pointers: Use azelaic acid at night, as the final step in your skin care routine to prevent it from smearing. Apply azelaic acid as a spot treatment. Use a cotton bud for precision, blending the application out so it doesn’t leave a sharp demarcation. Wait at least 30 minutes before lying down in bed and sleeping.  If you smear the azelaic acid all over without precision, what that means is that you could wind up with a dark spot and a light circle around it. The same applies to pigmentation inhibitors including Kojic acid, arbutin & hydroquinone. Precision & timing for best results.