
Azelaic Acid: Treats acne and rosacea bumps; may also help uneven pigmentation. Licorice Root Extract: Some licorice-derived compounds are studied for uneven pigmentation.


Choose for acne or rosacea bumps, especially when uneven tone is also a concern.
Consider as an optional pigment ingredient; independent clinical evidence is limited.
Can you use both?
A gentle pairing for dark marks and redness.
Compare uses by strength of evidence. Evidence level describes confidence in a benefit, not its size.












Helps calm inflammation: Acts on pathways involved in acne and rosacea. Affects pigment production: Tyrosinase-related activity may help dark marks.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.

Contains several active compounds: Glabridin and liquiritin have different actions. May help uneven pigmentation: Extracts and clinical evidence vary.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Built from where each one usually sits in a routine. Introduce one at a time.
Azelaic acid strength should be read together with the product’s indication. Prescription examples include 15% gel for inflammatory rosacea and 20% cream for acne.
15%
20%
Prescription rosacea formulation
Gel formulations are labeled for inflammatory papules and pustules of rosacea. They are not simply a weaker version of a 20% acne cream.
Prescription acne cream
A cream strength used for acne. The cream base and indication differ from the 15% rosacea gel.
Choosing a strength: Choose by the concern and finished product. Cosmetic azelaic acid products are not automatically equivalent to prescription formulations.
Higher strengths: Stinging and irritation can limit use. A larger number does not prove better delivery or better results for a different diagnosis.
Formula matters: Gel, foam and cream vehicles affect delivery and tolerability. Do not compare their percentages as if they were identical formulations.
Licorice root extract contains multiple compounds, including liquiritin and glabridin. Whole-extract percentages do not reveal the dose of these individual compounds.
Choosing a strength: Look for the named extract or purified compound and evidence for the finished product.
Higher strengths: There is no established universal percentage range or proof that higher whole-extract concentrations improve pigmentation.
Formula matters: A small study of liquiritin cannot establish a recommended strength for every licorice extract, species, or formulation.
Approximate windows, not promises.
First few weeksAssess tolerance and texture; immediate softness can come from the base formula.
First few weeksAssess tolerance first; pigment change is usually slower.
4–8 weeksSubtle changes may appear in some tested products; evidence varies.
4–8 weeksSome studied regimens begin showing pigment improvement.
8–12 weeksCompare photographs in the same lighting and reassess benefit.
8–12 weeksA useful review point for benefit and irritation.
3–6 monthsPhotoaging trials often need several months; expect modest rather than dramatic change.
3–6 monthsMany melasma trials assess results over three to four months; recurrence is common.
6–12 monthsLong-term evidence is limited for many cosmetic actives; continue only if useful.
6–12 monthsLong-term use depends on the active; follow a monitored plan rather than extending treatment automatically.
Stinging, itching and dryness can occur; reduce use for persistent irritation.
Botanical extracts can cause allergy or stinging; check the complete formula.
Stop for persistent burning, swelling, blistering or a new rash. Seek urgent care for breathing difficulty or a severe allergic reaction.
Stop for persistent burning, swelling, blistering or a new rash. Seek urgent care for breathing difficulty or a severe allergic reaction.
Choose a simple formula and test a small area first. Individual tolerance matters more than an ingredient’s reputation for being gentle.
Choose a simple formula and test a small area first. Avoid actively inflamed or broken skin unless the product is specifically directed for it.
Do not use a cosmetic product as a substitute for diagnosis of an unexplained, changing or persistent skin problem.
Do not use a cosmetic product as a substitute for diagnosis of an unexplained, changing or persistent skin problem.
It is the usual first choice. Very little is absorbed through the skin, it has a long record, and it is what dermatologists switch people to when retinoids stop. Confirm with the doctor managing your pregnancy.
Data are limited; ask the clinician managing your pregnancy.
On the skin. The finished product delivers azelaic acid in a particular vehicle.
Entering skin. Below the 500 Da guideline; delivery still depends on the formula, solubility, stability and skin condition. Size does not prove effectiveness or penetration depth.
Conversion. No activation step is established as necessary for its intended topical role.
Skin response. Acts on inflammation, acne-related bacteria and pigment pathways; it is not simply an exfoliating peel.
Additional effects. Proposed pathways do not establish a measured depth of delivery or clinical benefit beyond the studies cited.
On the skin. The finished product delivers licorice root extract in a particular vehicle.
Entering skin. No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.
Conversion. No activation step is established as necessary for its intended topical role.
Skin response. Compounds such as liquiritin and glabridin have different pigment-related actions; they are not interchangeable extracts.
Additional effects. Proposed pathways do not establish a measured depth of delivery or clinical benefit beyond the studies cited.
Choose for acne or rosacea bumps, especially when uneven tone is also a concern.
Two large vehicle-controlled trials support 15% gel for papulopustular rosacea. Acne has guideline support, but a 10% cosmetic serum should not be assumed equivalent to a studied prescription formula.
Consider as an optional pigment ingredient; independent clinical evidence is limited.
A 20-woman split-face study tested a specific liquiritin cream for four weeks with sun protection. It does not establish that all licorice extracts treat melasma or rosacea.
Sources