Ingredient glossary

THD Ascorbate

What THD Ascorbate does for your skin, who it suits, and what to watch for.

INCI: Tetrahexyldecyl Ascorbate · Also: Tetrahexyldecyl Ascorbic Acid

Solid and proven

In short: THD Ascorbate delivers brightening and antioxidant, suits most skin types, and the evidence behind it is moderate. One thing to know: needs the right pH to work.

What it does
Brightening, antioxidant
Best for
Most skin types
Watch out
Needs the right pH to work
Evidence
Moderate
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The molecule

Tap to enlarge
Chemical structure of THD Ascorbate (Tetrahexyldecyl Ascorbate)

The Glow take

One of the ingredients I trust most.

When your goal is fading dark spots and evening out tone, THD Ascorbate delivers, with a solid amount of evidence behind it. It only performs at the right pH, so it is worth buying from brands that get the formulation details right.

— Maya

What it does

  • brightening
  • antioxidant
  • anti aging

moderate evidenceIn vitro models and small clinical trials with thirty percent serum show meaningful melasma and tone improvement but the overall evidence base is still modest.

On a label: usually effective at 5-30%.

Who it's for, and who should skip it

Tends to suit

  • normal
  • combo
  • oily
  • dry
  • pigmentation
  • photoaged

Approach with care

  • very sensitive
  • Clogs poresLow
  • Irritation riskLow
  • pH-dependentIts effect depends on the product's pH

How it fits each skin type

  • DrySuits
  • CombinationSuits
  • OilySuits
  • SensitiveTake care

Often chosen for pigmentation, photoaged.

Where it fits in your routine

WhenMorning
Where in the orderAfter cleansing, under your SPF

Plays well with

THD Ascorbate, answered

Is THD Ascorbate safe during pregnancy?

Yes. THD Ascorbate 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 THD Ascorbate?

Approach THD Ascorbate with care if any of these apply to you: very sensitive.

What concentration of THD Ascorbate actually works?

THD Ascorbate tends to do its job in the 5 to 30% range. Much lower and it is likely underdosed.

Commonly confused with

  • Vitamin C (LAA)Pure vitamin C is the strongest but least stable. THD ascorbate is an oil-loving derivative that trades some punch for a gentler, steadier feel.

This, for every label you own

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Sources & how we reviewed this

Last reviewed July 2026. Educational information about a cosmetic ingredient, not medical advice.