Hydroxycinnamic acid

PhytochemicalPhenolic acid

What is it

Hydroxycinnamic acids are a class of plant polyphenols that includes caffeic, ferulic, p-coumaric, and sinapic acids. They are widely distributed in fruits, vegetables, coffee, and whole grains and are often listed as a standardization marker in plant extracts.

Evidence for 1 use

AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.

Vascular and antioxidant support

Limited Evidence

Observational studies link polyphenol-rich diets, including hydroxycinnamic acids, to lower cardiovascular risk. Trials of isolated supplements show smaller and less consistent effects.

How it works

These compounds are absorbed both as free acids and after release from esterified or glycosylated forms during digestion. They are extensively metabolized in the liver and gut, producing conjugates with antioxidant and possibly anti-inflammatory activity. Population studies of polyphenol-rich diets and small interventional trials suggest benefits for vascular function and oxidative stress markers. In supplements, "hydroxycinnamic acids" usually refers to a standardized fraction within a botanical extract rather than a specific isolated compound.

Dosage

There is no established intake target for hydroxycinnamic acids specifically. Western diets supply hundreds of milligrams per day, mostly from coffee. The DSLD does not list a single supplement dose.

When and how to take it

No specific timing required. Foods rich in hydroxycinnamic acids can be eaten throughout the day.

1 commercial form

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Polyphenol extract standardized to hydroxycinnamic acids

Found in artichoke, green coffee, and other plant extracts.

Variable based on conjugation state

Safety

Hydroxycinnamic acids consumed in food amounts are well tolerated. Concentrated extracts have not been linked to serious adverse effects at typical supplement doses, but high doses in isolation are less studied.

Who should be cautious

Generally low concern. Pregnant or breastfeeding people should stay within dietary amounts rather than high-dose extracts.

Interactions

No major drug interactions are well documented at usual dietary or supplement intakes.

Food sources

Coffee

Amount
Major dietary source (chlorogenic acid)
%DV
—

Whole grains

Amount
Ferulic acid
%DV
—

Berries and citrus

Amount
Caffeic and p-coumaric acids
%DV
—

Frequently asked questions

Is chlorogenic acid a hydroxycinnamic acid?⌄

Chlorogenic acid is an ester of caffeic acid (a hydroxycinnamic acid) with quinic acid, so it belongs to the broader hydroxycinnamic acid family.

Are coffee polyphenols the same?⌄

Coffee's main polyphenols are chlorogenic acids, which are major hydroxycinnamic acid sources in the diet.

References

Hydroxycinnamic acid on Wikidata — Wikidata link

Hydroxycinnamic acid (ChEBI:24689) — ChEBI link

Hydroxycinnamic acid on NIH DSLD (US supplement label database) — NIH Dietary Supplement Label Database link

Research on Hydroxycinnamic acid (PubMed search) — PubMed link

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Evidence-based·How we grade evidence

Disclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.