Limonene

PhytochemicalTerpeneBest with a meal

What is it

D-limonene is a monoterpene found in the peel of citrus fruits, responsible for their characteristic scent. It is studied for digestive support (particularly GERD/heartburn) and chemopreventive effects.

Evidence for 1 use

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

Heartburn / GERD

Limited Evidence

Small clinical trials suggest d-limonene reduces heartburn symptoms, possibly through coating effects on the esophagus and stomach.

How it works

D-limonene is highly lipophilic and partitions into stomach lining, where it may help neutralize gastric acid and improve mucosal protection. It is metabolized to perillyl alcohol and other compounds with potential antitumor activity in animal models. Clinical evidence is best for heartburn/GERD relief. Several small trials suggest meaningful symptom reduction. Chemopreventive evidence is largely preclinical.

Dosage

Studies for heartburn use 1000 mg of d-limonene every other day. Doses up to 2000 mg daily have been studied in cancer trials.

When and how to take it

WHEN: For GERD, every other day with a meal. HOW: Take with water; effects on heartburn may appear within days to weeks.

1 commercial form

Compare the main delivery options and what they’re best suited for.

D-limonene (purified)

Standard supplement form, typically in softgel capsules.

Lipophilic; well-absorbed orally.

Safety

Generally well tolerated. Common side effect is citrusy belching. May cause stomach upset and (rarely) allergic skin reactions. GRAS-listed as a food flavoring.

Who should be cautious

Limited specific safety data in pregnancy and breastfeeding. Otherwise no specific contraindications established at typical supplement doses.

Interactions

May affect CYP enzyme activity at high doses. Theoretical interaction with acid-reducing medications (potential additive effect on heartburn).

Food sources

Citrus peel (orange, lemon, grapefruit)

Amount
Variable
%DV
—

Frequently asked questions

Will d-limonene cure my heartburn?⌄

Small studies suggest meaningful symptom reduction in many people. It may not work for everyone, and persistent GERD warrants evaluation.

References

Limonene on Wikidata — Wikidata link

Limonene (ChEBI:15384) — ChEBI link

Limonene (PubChem CID 22311) — PubChem link

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

Research on Limonene (PubMed search) — PubMed link

Track Limonene with Pilora

Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.

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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.