Hydroxycinnamic Acid
Umbrella name for a group of phenolic antioxidants: caffeic, ferulic, sinapic, coumaric acids. Protect plant tissues from UV. In formulas added as stabilizers of more sensitive actives – e.g. keep vitamin C from oxidation. Standalone effect on skin is modest.
Evidence by route
Topical application
Antioxidant class with confirmed in vitro and in vivo activity. Standalone cosmetic effect is modest, main value is vitamin C stabilization and photoprotective synergy.
- Lin FH et al. Ferulic acid stabilizes a solution of vitamins C and E and doubles its photoprotection of skin. J Invest Dermatol 2005;125(4):826-832. PMID 16185284
How to read tiers A–F
- CWeak evidence. In vitro data, open-label studies, or expert consensus
Tolerability and safety
- Irritation potential
- Low
- Allergen risk
- Moderate
- Pregnancy
- Safe
- Suitable for
- Normal, Dry, Combination, Oily, Sensitive
- Use with caution
- Sensitive
About this ingredient
Hydroxycinnamic Acids are a group of phenolic antioxidants: caffeic, ferulic, sinapic, and coumaric acids. They form in plants from the amino acid phenylalanine and protect tissues from UV-induced oxidative stress. Where applied. Vitamin C serums and creams, anti-aging and photoprotection formulas. Most often as stabilizer of more sensitive actives (e.g., ferulic acid keeps L-ascorbic acid from oxidizing, SkinCeuticals CE Ferulic formula). Cosmetic concentration is typically 0.1-1%. Evidence base. Caffeic and ferulic acids in a formula with vitamins C and E double photoprotection from UVA-induced oxidative damage in vivo (Lin 2005). Standalone effect on skin without other antioxidants is modest – few clinical RCTs. Safety. CIR confirmed safety of ferulic and caffeic acids at cosmetic concentrations. Irritation is rare; in sensitive skin transient erythema is possible in the first days of use. Pregnancy and lactation – safe topically. Suitable for all skin types, especially for antioxidant protection in photoaging and pigmentation.
Frequently asked questions
Is Hydroxycinnamic Acid safe during pregnancy?
Hydroxycinnamic Acid is considered safe during pregnancy at typical cosmetic concentrations. Systemic absorption through the skin is minimal.
What skin types is Hydroxycinnamic Acid for?
Hydroxycinnamic Acid suits: normal, dry, combination, oily, sensitive. Use with caution in: sensitive.
What is Hydroxycinnamic Acid and what does it do in cosmetics?
Umbrella name for a group of phenolic antioxidants: caffeic, ferulic, sinapic, coumaric acids.
What's the INCI name for Hydroxycinnamic Acid?
The INCI name is Hydroxycinnamic Acid. It may also appear as: p-Coumaric Acid, Cinnamic Acid Derivative.
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