Cysteamine vs Licorice Root Extract

Cysteamine: Can reduce melasma pigmentation in tested topical formulas. Licorice Root Extract: Some licorice-derived compounds are studied for uneven pigmentation.

Research updated 2026-10-25

Four cysteamine products: a Senté tube, an Omic+ cream and box, a 5% cysteamine serum dropper and a Cyspera bottle

Five licorice root products on white, including two Acwell bottles, Éminence, Horbäach liquid extract and Versed

Which one?At a glance What it helps Diagrams Using both Strengths Results Safety How it works Questions

Which one is right for you?

Choose Cysteamine if…

Consider for diagnosed melasma when a suitable topical option is needed.

Diagnosed melasma
Hydroquinone isn’t suitable
You can follow short-contact wash-off

Choose Licorice Root Extract if…

Consider as an optional pigment ingredient; independent clinical evidence is limited.

Mild uneven tone
Sensitive skin that dislikes stronger pigment actives
Modest expectations

Fine together

Can you use both?

Licorice is soothing and can help offset cysteamine irritation.

At a glance

● Cysteamine

● Licorice Root Extract

Type

Pigment-targeting active

Botanical pigment-targeting mixture

What it does

Can reduce melasma pigmentation in tested topical formulas.

Some licorice-derived compounds are studied for uneven pigmentation.

Best for

Melasma

Melasma; Uneven Skin Tone

Studied concentrations

5% cream in controlled melasma trials; contact instructions vary by product.

Extracts are not standardized; the cited small study used a liquiritin cream.

When to use

On the schedule specified for the product or prescribed treatment.

Time to results

Usually assessed over 8–16 weeks

Irritation

Odour, stinging and irritation may limit use; follow wash-off instructions.

Botanical extracts can cause allergy or stinging; check the complete formula.

Sensitive skin

Choose a simple formula and test a small area first. Avoid actively inflamed or broken skin unless the product is specifically directed for it.

Available

Prescription or cosmetic status depends on the active, formula and country; check the label.

What it helps

Compare uses by strength of evidence. Evidence level describes confidence in a benefit, not its size.

Evidence level

Cysteamine

Licorice Root Extract

Moderate evidenceSome supportive research

Flat tan patches with soft irregular edges across the forehead and upper cheek of an adult with light skin, the surface completely smooth.

Melasma

A placebo-controlled trial found reduced pigmentation with 5% cream.

—

Limited evidenceEarly or small studies

—

Melasma

A small study investigated a specific liquiritin cream.

Uneven Skin Tone

Possible pigment benefit is based on small compound-specific studies.

Insufficient evidence

Flat light-brown residual marks on a fair cheek.

Post-Inflammatory Hyperpigmentation

The cited melasma trial does not establish fading of every type of dark mark.

The front of a forearm on fair skin. Two pale patches with sharp edges sit against lightly tanned skin, and the difference between the patch and the skin around it is subtle.

Vitiligo

The reviewed sources do not establish this ingredient as a treatment for this concern.

Sensitive Skin

The reviewed sources do not establish this ingredient as a treatment for this concern.

Vitiligo

The reviewed sources do not establish this ingredient as a treatment for this concern.

Redness and fine superficial vessels across a light-skinned cheek and nose.

Rosacea

The cited pigment study did not test rosacea.

Acne

The reviewed sources do not establish this ingredient as a treatment for this concern.

How it works

Cysteamine mechanism diagram. Affects melanin formation: Cysteamine acts through several pigment pathways. May help melasma: The formula, contact time and tolerance matter. — Open full-size diagram
Diagram explanation and sources
Affects melanin formation: Cysteamine acts through several pigment pathways. May help melasma: The formula, contact time and tolerance matter.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Source 1

Licorice Root Extract mechanism diagram. Contains several active compounds: Glabridin and liquiritin have different actions. May help uneven pigmentation: Extracts and clinical evidence vary. — Open full-size diagram
Diagram explanation and sources
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.
Source 1

Using both in one routine

Built from where each one usually sits in a routine. Introduce one at a time.

Morning

Step 1

Cleanser

Step 2

Licorice Root ExtractMorning or night

Step 3

Moisturizer

Step 4

Sunscreen

Night

Step 1

Cleanser

Step 2

Licorice Root ExtractMorning or night

Step 3

CysteamineNight

Step 4

Moisturizer

Strengths and forms

Concentrations

5% cysteamine cream is the main concentration studied for melasma. Contact time is product-specific; some studied formulas are short-contact treatments rather than overnight creams.

Studied melasma cream

Controlled trials studied this strength. One short-contact trial used a specific cream; follow the current product’s instructions rather than copying a study schedule.

Choosing a strength: Choose a finished topical product with clear instructions for how long to leave it on and when to rinse.

Higher strengths: There is no established benefit from escalating beyond the studied strength. Burning, redness or a persistent rash are reasons to stop and reassess.

Formula matters: Stabilization, the base cream and exposure time affect tolerability. Different cysteamine formulations need not have identical instructions.

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.

Forms

Cream

Serum · Cream

When you’ll see results

Approximate windows, not promises.

● Cysteamine

● Licorice Root Extract

First few weeks

First few weeksAssess tolerance first; pigment change is usually slower.

4–8 weeks

4–8 weeksSome studied regimens begin showing pigment improvement.

8–12 weeks

8–12 weeksA useful review point for benefit and irritation.

3–6 months

3–6 monthsMany melasma trials assess results over three to four months; recurrence is common.

6–12 months

6–12 monthsLong-term use depends on the active; follow a monitored plan rather than extending treatment automatically.

Safety and sensitive skin

Common reactions

Odour, stinging and irritation may limit use; follow wash-off instructions.

Botanical extracts can cause allergy or stinging; check the complete formula.

When to stop

Stop for persistent burning, swelling, blistering or a new rash. Seek urgent care for breathing difficulty or a severe allergic reaction.

Sensitive or inflamed skin

Choose a simple formula and test a small area first. Avoid actively inflamed or broken skin unless the product is specifically directed for it.

Important limits

Do not use a cosmetic product as a substitute for diagnosis of an unexplained, changing or persistent skin problem.

Pregnancy

Data in pregnancy are limited; ask the clinician managing your pregnancy before using.

Data are limited; ask the clinician managing your pregnancy.

How it works

In the skin

On the skin. The finished product delivers cysteamine 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 pigment-related pathways; the cream, contact time and tolerance influence its practical effect.

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.

Getting in

Below the 500 Da guideline; delivery still depends on the formula, solubility, stability and skin condition. Size does not prove effectiveness or penetration depth.

No single molecular mass. The 500 Da guideline cannot be applied to this whole ingredient family or mixture.

Common questions

Cysteamine:What should I choose cysteamine for?

Consider for diagnosed melasma when a suitable topical option is needed.

Cysteamine:How strong is the evidence?

A small placebo-controlled study supports 5% cream over four months. Active-comparator studies are small and do not prove equal efficacy to hydroquinone. The mass shown refers to the free base, not its hydrochloride salt.

Licorice Root Extract:What should I choose licorice root extract for?

Consider as an optional pigment ingredient; independent clinical evidence is limited.

Licorice Root Extract:How strong is the evidence?

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