Ingredient glossary
Denatured Alcohol
On your shelf ✓What Denatured Alcohol does for your skin, who it suits, and what to watch for.
INCI: Alcohol Denat · Also: SD Alcohol 40, Ethanol, Alcohol, Alcohol Denat.
In short: Denatured Alcohol delivers solvent and penetration enhancer, suits oily skin best, and the evidence behind it is moderate. One thing to know: can irritate, ease in slowly.
- What it does
- Solvent, penetration enhancer
- Best for
- Oily skin
- Watch out
- Can irritate, ease in slowly
- Evidence
- Moderate
- How long
- Straight away
how it was measured
Measured on Surface sebum dissolved and carried off as the solvent evaporates - an immediately degreased, matte surface; on contact, by mechanism.
The molecule
The Glow take
The carrier, not the treatment.
Denatured Alcohol is the base that carries the real ingredients, not something that treats skin on its own. Judge the formula by what sits further up the list.
— Maya
What it does
- solvent
- penetration enhancer
- astringent
moderate evidenceBarrier and irritation data show denatured alcohol increases transepidermal water loss and irritation with repeated or high-concentration use despite low…
Why we say this
- Barrier and irritation data show denatured alcohol increases transepidermal water loss and irritation with repeated or high-concentration use despite low systemic toxicity on intact skin.
A solvent has no effective concentration for its job in a cosmetic; what has been measured is the other direction.
Why we say this
- Patch tests with 60 to 100% ethanol on 15 volunteers changed neither barrier function nor erythema but lowered skin hydration, and an 80% ethanol wash irritated less than 0.5% sodium lauryl sulfate and even protected skin washed with the detergent (Loffler 2007).
- Repeated alcohol disinfectant irritated 15 volunteers less than a detergent did (Pedersen 2005), while alcohol rub on water-softened skin raised water loss in 20 (Plum 2020).
- Antiseptic hand rubs work at 60 to 80% ethanol; toners and serums carry 0.5 to 20%, and at those levels the measured effect is degreasing and a fall in hydration, not a dose of anything.
The solvent family, at a glance
2 solvent entries in the base, Denatured Alcohol among them. 2 of the 2 are a solvent.
- Denatured Alcohol46 Da
- Isopropyl Alcohol60 Da
Who it's for, and who should skip it
Tends to suit
- oily
- acne prone
Approach with care
- very sensitive
- compromised barrier
- rosacea
- eczema
- Clogs poresLow
- Irritation riskHigh
How it fits each skin type
- DryNeutral
- CombinationNeutral
- OilySuits
- SensitiveTake care
Often chosen for acne prone. Take extra care if any of these apply to you: compromised barrier, rosacea, eczema.
Where it fits in your routine
This one works on contact — there is nothing to wait for.
What that covers, and what it does not
- Measured on: Surface sebum dissolved and carried off as the solvent evaporates — an immediately degreased, matte surface.
- Ethanol dissolves surface lipid and flashes off within about a minute, so the degreasing is a solvent effect complete on application rather than a sensory impression, and it is the only skin-facing result the ingredient can claim.
- Its other measured human effect is harm — raised transepidermal water loss and irritation with repeated or high-level use — which accrues over days and is not a result a user is waiting for.
- Its principal job, dissolving actives and speeding drying, happens inside the bottle and has no skin clock; this row is not not-applicable only because alcohol toners are sold on an astringent, oil-control claim.
Mechanism; human barrier studies of repeated ethanol exposure characterise the TEWL and irritation side, not an onset for the degreasing.
Denatured Alcohol, answered
Is Denatured Alcohol safe during pregnancy?
Yes. Denatured Alcohol is considered safe to use during pregnancy and breastfeeding. As with anything, if you are unsure it is worth a quick word with your doctor or midwife.
Who should avoid Denatured Alcohol?
Approach Denatured Alcohol with care if any of these apply to you: very sensitive, compromised barrier, rosacea, and eczema. Its irritation risk is high, so introduce it slowly and patch test first.
What concentration of Denatured Alcohol actually works?
Its concentration is rarely printed on the label, so use the ingredient list as your clue: near the top third it is likely doing real work, near the bottom it is more of a sprinkle.
Commonly confused with
- Cetyl AlcoholSame word, opposite jobs. Cetyl is a waxy, conditioning fatty alcohol; denatured alcohol is the fast-drying solvent kind.
This, for every label you own
One ingredient is easy. A full label is where it gets confusing. The Ingredient Decoder reads any product and tells you the honest truth, ingredient by ingredient.
Sources & how we reviewed this
What changed on this page
- : label names
- : what the EU regulates
- : the effective dose from trials