Last verified: today
Grapefruit
Also known as: Citrus paradisi, grapefruit extract, grapefruit essential oil, grapefruit juice, nootkatone, GFJ
Evidence under review. — Not yet rated
Citrus fruit with drug interaction risks. Some evidence for aromatherapy and skin benefits. Not a proven supplement.
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What it does
Grapefruit is a citrus fruit whose juice, peel, and essential oil are used in supplements and aromatherapy. Inhaled grapefruit essential oil showed some benefit for premenstrual symptoms in a...
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Evidence quality
Evidence base hasn't been formally rated yet. See research below.
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Clinical dose
No established dose
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Found in
What the Science Says
Grapefruit is a citrus fruit whose juice, peel, and essential oil are used in supplements and aromatherapy. Inhaled grapefruit essential oil showed some benefit for premenstrual symptoms in a small clinical trial. A combination of grapefruit and rosemary extract showed preliminary photoprotective and anti-aging skin benefits in an early human study. Grapefruit's most well-documented effect is blocking a liver enzyme (CYP3A) that metabolizes many medications, which can dangerously raise drug levels in the blood.
What It Doesn't Do
Won't reliably burn fat or boost metabolism — no evidence from these studies. Not a proven treatment for any disease. Aromatherapy benefits don't translate to taking a grapefruit pill. Don't confuse flavoring in laxative products with any therapeutic grapefruit effect.
Evidence-Based Benefits
Inhaled grapefruit essential oil reduced premenstrual syndrome scores including anxiety, fatigue, and bloating.
Weak EvidenceEffective at: No established dose; inhalation 30 min 3x/day for 3 menstrual cycles used in study
Oral grapefruit and rosemary extract combination showed early evidence of UV protection and anti-aging skin benefits.
Weak EvidenceEffective at: No established dose
Grapefruit juice significantly raises blood levels of CYP3A-metabolized drugs like tacrolimus, creating serious interaction risks.
Moderate EvidenceEffective at: Even small amounts of grapefruit juice can trigger interactions
Absorption & Bioavailability
Unknown for supplement forms. Grapefruit juice is well-known to inhibit intestinal CYP3A enzymes, which can dramatically increase absorption of certain drugs — this is a risk, not a benefit.
Red Flags to Watch For
- Grapefruit juice and extract can dangerously increase blood levels of many prescription drugs including tacrolimus, statins, calcium channel blockers, and others — always check with your pharmacist
- Most supplement products (1000+ on NIH DSLD) use grapefruit as a minor ingredient with no clinical evidence for the specific formulation
- Aromatherapy studies used multi-oil blends, so grapefruit's individual contribution cannot be isolated
- Early-phase nanocarrier studies involving grapefruit-derived vesicles are exploratory with very small sample sizes — far from proven therapies
Products Containing Grapefruit
See how Grapefruit is used in these analyzed products:
Research Sources
- PubMed
- NIH DSLD
This information is for educational purposes only and is not medical advice. Always consult a healthcare professional before starting any supplement regimen. Last updated: 2026-05-25