Ingredient glossary
Tretinoin
On your shelf ✓What Tretinoin does for your skin, who it suits, and what to watch for.
INCI: Tretinoin · Also: Retinoic Acid, All-trans Retinoic Acid
In short: Tretinoin delivers anti-aging support and anti acne, earns its place for acne prone and photoaged, and the evidence behind it is strong. One thing to know: not for pregnancy or breastfeeding; can irritate, ease in slowly.
- What it does
- Anti aging, anti acne
- Best for
- Acne prone, photoaged
- Watch out
- Not for pregnancy or breastfeeding; can irritate, ease in slowly
- Evidence
- Strong
- How long
- 2–4 weeks
The molecule
The Glow take
One of the ingredients I trust most.
When your goal is softening fine lines and keeping skin firm, Tretinoin delivers, and the research properly backs it up. Skip it while you are pregnant or breastfeeding, and the rest of the time bring it in slowly.
— Maya
What it does
- anti aging
- anti acne
- texture
- brightening
Tretinoin scores -2 on barrier support. It is one of only 8 ingredients in our glossary that go below zero there. A negative score means it asks something of the barrier rather than giving something back, which is why it needs introducing slowly and pairing with ingredients that do support the barrier. It is not a reason to avoid it: the same evidence that shows the irritation also shows the long-term gains. See where it sits against all 291 of them →
strong evidenceSystematic reviews consistently show tretinoin outperforms other topical agents for photoaging and acne, but tolerability limits its cosmetic use.
On a label: works best above 0.025%.
Who it's for, and who should skip it
Tends to suit
- acne prone
- photoaged
Approach with care
- pregnancy
- breastfeeding
- very sensitive
- Clogs poresLow
- Irritation riskHigh
How it fits each skin type
- DryNeutral
- CombinationNeutral
- OilyNeutral
- SensitiveTake care
Often chosen for acne prone, photoaged. Take extra care if any of these apply to you: pregnancy, breastfeeding.
Worried about purging? Here is what the trials actually measured →
Where it fits in your routine
Increases sun sensitivity while you are using it, so sunscreen matters more than usual.
Retinoid: the approved labelling states treated skin has heightened susceptibility to sunlight, directs that exposure to sunlight and sunlamps be minimised, and recommends sunscreen and protective clothing over treated areas.
FDA-approved tretinoin (Retin-A) prescribing information, sun exposure warning
Reckon on two to four weeks. No trial pins the exact point down; that is the standard clinical expectation.
What was measured, and in whom
Measured on: inflammatory and comedonal acne lesion counts, investigator-counted.
The approved Retin-A labelling states that therapeutic results should be noticed after two to three weeks while definite benefit can take more than six weeks, and that is the settled clinical expectation in acne practice; early weeks can transiently look worse. The photoageing outcome is a separate and much slower wait - the vehicle-controlled fine-wrinkling programmes run 16 to 24 weeks at 0.05-0.1%, so judging wrinkles at 12 weeks is premature. The expectation is set on prescription 0.025-0.1% formulations, not on low-dose cosmetic imitations.
FDA-approved tretinoin (Retin-A) prescribing information, dosage and administration timing statement; the tretinoin 0.05% emollient cream photodamage programme for the wrinkle clause, described rather than numbered.
Light, and how to keep it
Tretinoin breaks down in light. The packaging is doing real work: opaque, and closed between uses.
The molecule photodegrades in topical formulations; an entire delivery literature exists to measure and slow it, including nanosuspensions built specifically to improve its photostability.
PMID:24135683(abstract)
Plays well with
- ceramides
- niacinamide
- panthenol
Tretinoin, answered
Is Tretinoin safe during pregnancy?
No. Tretinoin is best avoided during pregnancy and breastfeeding. If you are pregnant or trying, leave this one out and ask your doctor about a safe alternative.
Who should avoid Tretinoin?
Approach Tretinoin with care if any of these apply to you: pregnancy, breastfeeding, and very sensitive. Its irritation risk is high, so introduce it slowly and patch test first.
What concentration of Tretinoin actually works?
Research tends to show Tretinoin starts pulling its weight above 0.025%. If a brand prints the percentage, that is the number to look for.
Does Tretinoin go off?
It breaks down in light, and that is the part that has been measured. The molecule photodegrades in topical formulations; an entire delivery literature exists to measure and slow it, including nanosuspensions built specifically to improve its photostability. So the packaging is not decoration: opaque, and closed between uses. Heat, air and simple age matter too, and we have not sourced numbers for those, so treat this as one reason a product weakens rather than as a shelf life.
During pregnancy
Leave Tretinoin out while you are pregnant or breastfeeding. It sits on the list of ingredients usually held back during this time.
When in doubt, check with your doctor or midwife. They outrank any website, including this one.When it is worth booking →
Commonly confused with
- RetinolTretinoin is the prescription acid form that works right away. Retinol is the gentler over-the-counter version your skin has to convert first.
Just started Tretinoin?
Where Tretinoin sits
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