About D-Limonene
D-Limonene is the primary monoterpene in citrus peels (~90% of lemon peel oil). Only 2 small GERD studies exist (n=13 and n=19), both from a patent holder, showing heartburn relief. No meta-analyses or large RCTs. Animal and in-vitro studies suggest antioxidant and anti-inflammatory properties but these have not been confirmed in human trials.
What D-Limonene supports
- May relieve GERD/heartburn (limited evidence, 2 small studies)
- Citrus-derived monoterpene with antioxidant properties
How much D-Limonene to take
Clinical studies typically use 500–1000 mg of D-Limonene. Pure d-limonene softgels are 250–1000 mg. Lemon peel products contain ~5–10% limonene by weight.
- Effective range
- 500–1000 mg
Forms of D-Limonene compared
- Pure d-limonenePremiumPure d-limonene softgels — the form used in GERD and gut-motility trials.
- Lemon peel extractBudgetWhole peel extract — only ~5–10% d-limonene by weight.
Clinical evidence
Limited clinical evidence. Only 2 small studies (13-19 participants) for heartburn, both from a patent holder
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