Ingredient glossary
Sodium Hydroxide
On your shelf ✓What Sodium Hydroxide does for your skin, who it suits, and what to watch for.
INCI: Sodium Hydroxide · Also: NaOH, Caustic soda
In short: Sodium Hydroxide delivers pH adjuster, plays a broad, supporting role, and the evidence behind it is strong. One thing to know: introduce it gently; needs the right pH to work.
- What it does
- PH adjuster
- Best for
- A broad, supporting role
- Watch out
- Introduce it gently; needs the right pH to work
- Evidence
- Strong
The Glow take
Nice to have, and nothing to overthink.
Sodium Hydroxide plays a quiet supporting role, rounding out a formula rather than being the reason you buy it.
— Maya
What it does
- pH adjuster
strong evidenceCIR and regulatory reports describe sodium hydroxide as a caustic pH adjuster that is safe up to about 10% leave on and 12.9% rinse off when formulated to be non irritating. Its effect is pH driven so use levels are kept very low to avoid corrosivity.
On a label: usually effective at 0.01-0.5%.
Who it's for, and who should skip it
Tends to suit
No specific skin type. It is a broadly used ingredient.
Approach with care
- very sensitive
- compromised barrier
- Clogs poresLow
- Irritation riskModerate
- pH-dependentIts effect depends on the product's pH
How it fits each skin type
- DryNeutral
- CombinationNeutral
- OilyNeutral
- SensitiveTake care
Take extra care if any of these apply to you: compromised barrier.
Where it fits in your routine
Plays well with
- emulsifiers
Sodium Hydroxide, answered
Is Sodium Hydroxide safe during pregnancy?
Yes. Sodium Hydroxide 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 Sodium Hydroxide?
Approach Sodium Hydroxide with care if any of these apply to you: very sensitive and compromised barrier. Its irritation risk is moderate, so introduce it slowly and patch test first.
What concentration of Sodium Hydroxide actually works?
Sodium Hydroxide tends to do its job in the 0.01 to 0.5% range. Much lower and it is likely underdosed.
This, for every label you own
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