Retinal vs retinol: what's the difference?

Key takeaways

• Retinol and retinal are both forms of vitamin A. Skin has to convert them into retinoic acid, the form that does the work, and retinal is one step closer.

• In lab studies, retinaldehyde ranked as more potent than retinol, and one trial found 0.05% retinal and 0.05% tretinoin both smoothed wrinkles at 18 weeks, with less irritation from retinal.

• The evidence is still limited. A 2021 review found little trustworthy evidence for over-the-counter retinol products, and many retinoid studies are small.

• Both can cause dryness, redness and peeling at first. Start every other night and wear sunscreen daily.

• Don’t use either during pregnancy.

What are retinol and retinal?

Both belong to the retinoid family, the vitamin A compounds used in skincare. Skin can’t use them directly. It converts them, step by step, into retinoic acid, also called tretinoin, the active form.

A 2006 review describes the chain: retinol is oxidized into retinaldehyde (retinal), which can then be oxidized into retinoic acid. Retinyl esters, like retinyl palmitate, sit one step before retinol. So the order runs:

• Retinyl esters (theoretically the least effective, since they need the most conversion)

• Retinol

• Retinal (retinaldehyde)

• Retinoic acid (tretinoin, prescription only)

Because retinal skips a step, it’s often described as faster-acting than retinol. The same review notes that retinol is 20 times less potent than tretinoin.

Retinal vs retinol: what the studies show

Retinal ranks above retinol in lab tests. In a 1994 study, researchers measured a marker of retinoid activity in human skin and found this order: retinoic acid, then retinaldehyde, then another retinoid, then retinol. The same study found 0.05% and 0.1% retinaldehyde on the face were well tolerated for up to three years in people with inflammatory skin conditions.

One trial compared retinal with tretinoin. In a 1998 trial of 125 people, 0.05% retinaldehyde and 0.05% retinoic acid both significantly reduced wrinkles and roughness at 18 weeks. Retinaldehyde was well tolerated throughout, while retinoic acid caused more irritation.

But the evidence isn’t settled. A 2021 review reread that same trial as showing no significant difference between retinaldehyde and the plain cream. It also concluded there’s “very little, if any, trustworthy evidence” supporting over-the-counter retinol products for aging skin. A 2024 systematic review suggested retinaldehyde can be considered a second-line option for people who can’t tolerate tretinoin, while noting that most studies comparing treatments with tretinoin are of poor quality.

Strength matters. In a small three-month trial of 40 women, both 0.05% and 0.1% retinaldehyde improved skin hydration and texture, but only 0.1% improved the look of pigmentation.

Is retinal better for acne?

It may have an extra edge. In a 2002 study, retinaldehyde was the only one of three retinoids tested that showed antibacterial activity, including against the bacteria linked to acne, and daily use reduced those bacteria on the skin. Researchers think the aldehyde group is responsible.

For acne itself, the retinoid with the most over-the-counter backing is adapalene. The FDA approved adapalene 0.1% gel for over-the-counter use in 2016, making it the first retinoid sold without a prescription for acne. Tretinoin, tazarotene and trifarotene still need a prescription.

Side effects

The most common side effect of any retinoid is what dermatologists call retinoid dermatitis: redness, peeling and dry skin. The 2006 review notes it usually shows up in the first few weeks and is more common with tretinoin than with retinol or retinaldehyde. DermNet also lists sun sensitivity and irritant contact dermatitis.

Cleveland Clinic lists dry, irritated skin, itching or burning, redness, peeling and sunburn as possible side effects of retinol. Early pimples can also appear when you start a retinoid. Our guide to skin purging explains what’s normal.

Which should you choose?

• New to retinoids or sensitive skin: start with a low-strength retinol. Our list of retinol products for beginners covers gentle options.

• Already using retinol with no irritation: retinal is a reasonable next step if you want something closer to retinoic acid.

• Acne-prone: retinal’s antibacterial activity is a plus, and adapalene is a well-studied over-the-counter option.

• Can’t tolerate tretinoin: retinal is often better tolerated, according to the trials above.

How to start using retinal or retinol

• Go slowly. The American Academy of Dermatology (AAD) suggests using the least-intense formula you can find, every other night at first, and building up slowly.

• Use a small amount. Cleveland Clinic suggests a pea-sized amount for the face.

• Apply at night and wear sunscreen by day. The AAD says retinoids can make skin more sensitive to the sun. Our guide to mineral vs chemical sunscreen explains the options.

• Don’t stack strong actives at first. Our guide to AHA vs BHA explains how exfoliating acids fit in, and our guide to skincare routine order shows where a retinoid goes.

• Keep it away from light and air. Vitamin A compounds are unstable, and a 2025 analysis of retinol products notes that packaging protects them from light and air, so opaque, airtight packaging helps.

Can you use retinal or retinol while pregnant?

No. The AAD says retinoids should not be used during pregnancy, and the American College of Obstetricians and Gynecologists recommends avoiding topical retinoids while pregnant, even though little is absorbed. Ask your doctor about alternatives.

Frequently asked questions

Is retinal stronger than retinol?

In lab studies, yes. Retinal is one conversion step closer to retinoic acid and ranked as more potent than retinol in a 1994 study. Strength also depends on the concentration and formula.

Is retinal as strong as tretinoin?

Not quite. One trial found 0.05% retinal and 0.05% tretinoin both improved wrinkles at 18 weeks, with less irritation from retinal, but a later review questioned that result. Tretinoin remains the best-studied option and needs a prescription.

Is 1% retinol the same as 1% retinal?

No. They’re different molecules, and retinal is one step closer to the active form, so the same percentage doesn’t mean the same strength. Retinal has been studied mostly at 0.05% to 0.1%.

Can you switch from retinol to retinal?

Yes. If your skin tolerates retinol well, you can switch to retinal. Start every other night again, since it may feel stronger at first.

How long does it take to see results from retinal?

Trials have measured results at three months and 18 weeks, with some effect still seen at 44 weeks. Give any retinoid at least a few months of consistent use before judging it.