Compare · Ingredients

Retinaldehyde vs Sulfur

Retinaldehyde: Some formulas improve photoaged texture and pigmentation over months. Sulfur: Used in some acne products and prescribed or compounded scabies regimens.

Research updated 2026-10-25

Four retinaldehyde products with two boxes on white, from Paula's Choice, Medik8, Naturium and Prequel

Four sulfur acne products: Kate Somerville EradiKate, De La Cruz 10% sulfur ointment, The Ordinary and Thayers

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

Which one is right for you?

Choose Retinaldehyde if…

Consider for photoaged texture; introduce slowly and judge the complete formula.

Fine lines and texture
Retinol isn’t enough
You can introduce it slowly

Choose Sulfur if…

Consider for an appropriate acne product; suspected scabies needs diagnosis and a complete plan.

Mild acne or a spot treatment
Sensitive skin that dislikes benzoyl peroxide
Smell is acceptable

Fine together

Can you use both?

A sulfur spot treatment can go alongside retinaldehyde. Watch for dryness.

At a glance

● Retinaldehyde

● Sulfur

Type

Vitamin A precursor (retinal)

Keratolytic and antimicrobial medicine

What it does

Some formulas improve photoaged texture and pigmentation over months.

Used in some acne products and prescribed or compounded scabies regimens.

Best for

Wrinkles and Fine Lines; Uneven Skin Tone

Acne; Scabies

Studied concentrations

0.05% and 0.1% creams in the cited three-month trial.

Acne products commonly use 3–10%; scabies ointments use separate 5–10% regimens.

When to use

At night; introduce gradually according to the product label.

Morning or night, as directed by the finished product.

Time to results

Assess over roughly 3 months; photoaging can take longer

Often 8–12 weeks in small cosmetic studies; results may be subtle

Irritation

Dryness, stinging and peeling can occur; avoid irritated areas.

Odour, dryness and irritation can limit use; avoid strong products on inflamed eczema.

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. Individual tolerance matters more than an ingredient’s reputation for being gentle.

Available

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

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

Retinaldehyde

Sulfur

Moderate evidenceSome supportive research

—

The finger webs and wrist on fair light skin, with small red bumps, several thin gray burrow lines a few millimetres long, and scratch marks across the area.

Scabies

CDC lists compounded 5–10% sulfur ointment as an alternative treatment.

Limited evidenceEarly or small studies

A relaxed forehead with faint shallow horizontal fine lines.

Wrinkles and Fine Lines

Small clinical studies suggest photoaging benefits from particular formulas.

Uneven Skin Tone.

Uneven Skin Tone

Only the 0.1% group improved the melanin index in the cited trial.

Inflamed acne on light skin. The spots sit in a patch of pink, and the ring of redness around each one is easy to see. A few have a yellow-white head, and the skin between them is dry and flaking.

Acne

Used in acne products, with less robust modern evidence than standard acne medicines.

Insufficient evidence

Inflamed acne on light skin. The spots sit in a patch of pink, and the ring of redness around each one is easy to see. A few have a yellow-white head, and the skin between them is dry and flaking.

Acne

The cited photoaging study did not establish treatment of acne.

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

Rosacea

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

A relaxed forehead with pronounced deep horizontal furrows.

Deep Wrinkles

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

Combination sulfacetamide/sulfur products do not establish sulfur alone as treatment.

Salmon-pink patches with fine greasy yellowish scale in the crease beside the nose and through the eyebrow on fair skin, with soft edges that fade into normal skin.

Seborrheic Dermatitis

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

Extreme close-up of light skin in an active eczema flare, too close to tell which part of the body it is. Blotchy pink-red inflammation covers the whole frame with no clear edge, with small raised bumps, fine dry scale and a few fresh scratch marks.

Eczema

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

Acne scarring on light skin. Small sharply cut pits and broad shallow dips across a cheek, several sitting inside faint flat pink marks, with no active spots.

Acne Scarring

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

How it works

Retinaldehyde mechanism diagram. Converts to retinoic acid: Skin enzymes can activate retinaldehyde. Changes cell activity: Retinoic acid acts through nuclear receptors. — Open full-size diagram
Diagram explanation and sources
Converts to retinoic acid: Skin enzymes can activate retinaldehyde. Changes cell activity: Retinoic acid acts through nuclear receptors.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Source 1

Sulfur mechanism diagram. Helps loosen surface keratin: Sulfur preparations can promote exfoliation. Acts against microbes: Effects depend on the preparation and intended use. — Open full-size diagram
Diagram explanation and sources
Helps loosen surface keratin: Sulfur preparations can promote exfoliation. Acts against microbes: Effects depend on the preparation and intended use.
Schematic illustration; not a measurement of skin penetration. Effects vary with ingredient identity and formulation.
Source 1 · Source 2 · Source 3

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

RetinaldehydeNight

Step 3

SulfurNight

Step 4

Moisturizer

Strengths and forms

Concentrations

0.05% and 0.1% retinaldehyde creams have been compared in a controlled photoaging trial. These percentages cannot be directly compared with retinol or tretinoin.

0.05%

0.1%

Lower studied retinal strength

A cream studied for skin texture and hydration. The result applies to that finished formula.

Higher studied retinal strength

Also studied for photoaging; not better for every measured outcome. Tolerance still determines whether a product suits you.

Choosing a strength: Choose retinaldehyde for its own formula and instructions, not a retinol-to-retinal conversion chart.

Higher strengths: A higher percentage may be harder to tolerate. Stronger products sold commercially do not automatically have stronger comparative clinical evidence.

Formula matters: Encapsulation, stability and the cream or serum base affect delivery. A percentage alone is not a measure of how much reaches skin cells.

Sulfur strength depends on the condition: U.S. OTC acne products use 3–10%, while compounded scabies ointments use a separate 5–10% range.

3–10%

5–10%

OTC acne range

For qualifying acne products. A wash, mask and leave-on product have different contact instructions.

Compounded scabies ointment

A clinician-directed alternative discussed by CDC. It is a separate treatment, not ordinary facial skincare.

Choosing a strength: Choose for the diagnosis and complete product. Sulfur-only acne products and prescription sulfacetamide/sulfur combinations are not the same.

Higher strengths: More sulfur is not automatically more useful, and dryness or irritation may limit use.

Formula matters: Wash-off versus leave-on use matters. Scabies treatment requires a whole treatment plan rather than choosing a percentage alone.

Forms

Serum · Cream

Mask · Spot treatment · Wash

When you’ll see results

Approximate windows, not promises.

● Retinaldehyde

● Sulfur

First few weeks

First few weeksAssess tolerance and texture; immediate softness can come from the base formula.

First few weeksAssess tolerance and texture; immediate softness can come from the base formula.

4–8 weeks

4–8 weeksSubtle changes may appear in some tested products; evidence varies.

4–8 weeksSubtle changes may appear in some tested products; evidence varies.

8–12 weeks

8–12 weeksCompare photographs in the same lighting and reassess benefit.

8–12 weeksCompare photographs in the same lighting and reassess benefit.

3–6 months

3–6 monthsPhotoaging trials often need several months; expect modest rather than dramatic change.

3–6 monthsPhotoaging trials often need several months; expect modest rather than dramatic change.

6–12 months

6–12 monthsLong-term evidence is limited for many cosmetic actives; continue only if useful.

6–12 monthsLong-term evidence is limited for many cosmetic actives; continue only if useful.

Safety and sensitive skin

Common reactions

Dryness, stinging and peeling can occur; avoid irritated areas.

Odour, dryness and irritation can limit use; avoid strong products on inflamed eczema.

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. Individual tolerance matters more than an ingredient’s reputation for being gentle.

Important limits

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.

Pregnancy

Retinoids are conventionally stopped in pregnancy and while trying to conceive. Ask the doctor managing your pregnancy. Azelaic acid is the usual alternative.

Topical sulfur is generally considered acceptable in pregnancy; ask the clinician managing your pregnancy.

How it works

In the skin

On the skin. The finished product delivers retinaldehyde 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. Skin can convert retinaldehyde into retinoic acid.

Skin response. Skin can convert retinaldehyde into retinoic acid, which influences cell activity through retinoid receptors.

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 sulfur in a particular vehicle.

Entering skin. Below 500 Da in this molecular form. Its useful surface action does not require deep delivery; the formula and skin condition matter.

Conversion. No activation step is established as necessary for its intended topical role.

Skin response. Promotes surface shedding and has antimicrobial activity; effects and instructions depend on the preparation.

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 500 Da in this molecular form. Its useful surface action does not require deep delivery; the formula and skin condition matter.

Molecule size

Retinaldehyde · 284 Da

Sulfur · 256 Da

Smaller than 500 Da passes the outer skin more easily. Size isn’t an effectiveness score.

500 Da guideline

Product examples

Retinaldehyde

Naturium Retinaldehyde Cream Serum 0.05%
Murad Retinal Resculpt Body Treatment

Sulfur

Murad Rapid Relief Acne Sulfur Mask
The Ordinary Sulfur 10% Powder-To-Cream Concentrate
Naturium The Revealer Sulfur Body Wash

Common questions

Retinaldehyde:What should I choose retinaldehyde for?

Consider for photoaged texture; introduce slowly and judge the complete formula.

Retinaldehyde:How strong is the evidence?

A 40-woman trial compared two active strengths without a retinoid-free vehicle group. It supports cautious formula-specific claims, not guaranteed superiority to retinol or acne medicines.

Sulfur:What should I choose sulfur for?

Consider for an appropriate acne product; suspected scabies needs diagnosis and a complete plan.

Sulfur:How strong is the evidence?

Modern isolated-sulfur acne evidence is limited; studies of sulfacetamide/sulfur cannot isolate sulfur. CDC describes sulfur ointment as a scabies option, but an acne wash is not a substitute for that regimen.

Sources

Sources and further reading

Dermapedia on YouTube