Compare · Ingredients

Cysteamine vs Hydroquinone

Cysteamine: Can reduce melasma pigmentation in tested topical formulas. Hydroquinone: Treats selected hyperpigmentation, including melasma, under an appropriate treatment plan.

Research updated 2026-10-25
Four cysteamine products: a Senté tube, an Omic+ cream and box, a 5% cysteamine serum dropper and a Cyspera bottleHydroquinone — Header Image
Which one?At a glanceWhat it helpsDiagramsUsing bothStrengthsResultsSafetyHow it worksQuestions

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 Hydroquinone if…

Choose for diagnosed stubborn pigment with professional guidance and a defined review point.

  • Stubborn melasma or dark marks
  • A clinician is supervising
  • You can take breaks between courses
Alternatives, not combined

Can you use both?

Both are strong pigment treatments. Cysteamine is often used between or instead of hydroquinone courses.

At a glance

● Cysteamine
● Hydroquinone
Type
Pigment-targeting active
Pigment-suppressing medicine
What it does
Can reduce melasma pigmentation in tested topical formulas.
Treats selected hyperpigmentation, including melasma, under an appropriate treatment plan.
Best for
Melasma
Melasma; Post-Inflammatory Hyperpigmentation; Sun Spots
Studied concentrations
5% cream in controlled melasma trials; contact instructions vary by product.
4% cream is a common prescription strength; local access rules vary.
When to use
On the schedule specified for the product or prescribed treatment.
On the schedule specified for the product or prescribed treatment.
Time to results
Usually assessed over 8–16 weeks
Usually assessed over 8–16 weeks
Irritation
Odour, stinging and irritation may limit use; follow wash-off instructions.
Can irritate; prolonged inappropriate use can cause paradoxical darkening (ochronosis).
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.
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.
Professional guidance; nonprescription hydroquinone skin-lightening products are not legally marketed in the US.

What it helps

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

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

Melasma

Clinical trials support improvement with monitored topical treatment.
Limited evidenceEarly or small studies
—
Flat light-brown residual marks on a fair cheek.

Post-Inflammatory Hyperpigmentation

Used for selected pigment after diagnosis; the cited trial studied melasma.
AI-generated educational illustration of Sun Spots: 1. Sun Spots Header — Light Skin; Lighter skin. Not a clinical photograph.

Sun Spots

May lighten selected benign spots; a changing lesion first needs diagnosis.
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 on light skin.

Sensitive Skin

The reviewed sources do not establish this ingredient as a treatment for this concern.
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.
A close crop of one lower eyelid and the top of the cheek on pale skin, no full face. The skin under the eye looks bluish-purple with fine veins showing, and a shallow hollow sits between the lid and the cheek.

Dark Circles Under the Eyes

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

Cysteamine

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

Hydroquinone

Hydroquinone mechanism diagram. Acts on tyrosinase pathways: Hydroquinone suppresses melanin synthesis. Targets excess pigmentation: Appropriate use and monitoring matter.
Open full-size diagram
Diagram explanation and sources

Acts on tyrosinase pathways: Hydroquinone suppresses melanin synthesis. Targets excess pigmentation: Appropriate use and monitoring matter.

Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.

Source 1 · Source 2

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
Moisturizer
Step 3
Sunscreen
Night
Step 1
Cleanser
Step 2
HydroquinoneNight
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.

5%

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.

4% is a common clinician-directed hydroquinone strength. In the U.S., hydroquinone skin-lightening products are not legally marketed over the counter; higher compounded strengths are not routine starting points.

4%

Clinician-directed strength

Used in melasma treatment and in the approved combination TRI-LUMA. Treatment length and the complete formula require medical guidance.

Choosing a strength: Get a diagnosis and a treatment plan for the pigmented area rather than choosing solely by concentration.

Higher strengths: More is not automatically better. Irritation and blue-black discoloration called ochronosis are important risks, especially with inappropriate or prolonged use.

Formula matters: Single-ingredient creams, compounded blends and TRI-LUMA are different products. A combination containing a steroid or retinoid needs its own instructions.

Forms
Cream
Cream · Triple cream

When you’ll see results

Approximate windows, not promises.

● Cysteamine
● Hydroquinone
First few weeks

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

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

4–8 weeks

4–8 weeksSome studied regimens begin showing pigment improvement.

4–8 weeksSome studied regimens begin showing pigment improvement.

8–12 weeks

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

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.

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.

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.

Can irritate; prolonged inappropriate use can cause paradoxical darkening (ochronosis).

When to stop

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.

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.

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.

Do not use to lighten normal skin broadly or continue through worsening pigmentation. US nonprescription hydroquinone skin-lightening products are not legally marketed.

Pregnancy

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

More of it is absorbed through the skin than with most topicals, so it is usually stopped. Azelaic acid is the common substitute. Ask the doctor 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 hydroquinone 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. Suppresses melanin synthesis through tyrosinase-related activity; targeted use and monitoring matter.

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.
Below the 500 Da guideline; delivery still depends on the formula, solubility, stability and skin condition. Size does not prove effectiveness or penetration depth.
Molecule size
Cysteamine · 77 Da
Hydroquinone · 110 Da
Smaller than 500 Da passes the outer skin more easily. Size isn’t an effectiveness score.
500 Da guideline

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.

Hydroquinone:What should I choose hydroquinone for?

Choose for diagnosed stubborn pigment with professional guidance and a defined review point.

Hydroquinone:How strong is the evidence?

The reviewed active-comparator melasma study was small with substantial attrition. Hydroquinone has broader clinical use, but this comparison does not support indefinite treatment or unsupervised high strengths.

Sources

Sources and further reading

  1. Evaluation of the efficacy of cysteamine 5% cream in the treatment of epidermal melasma: a randomized double-blind placebo-controlled trial. (2015)
  2. Evaluation of the efficacy of cysteamine cream compared to hydroquinone in the treatment of melasma: A randomised, double-blinded trial. (2021)
  3. FDA hydroquinone safety and access
  4. Short-contact 5% cysteamine clinical trial
  5. TRI-LUMA prescribing information
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