Supplement analysis backed by scientific evidence · PT

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Limited evidenceHeart & metabolic

Naringin

The bitter flavonoid of grapefruit. Almost all of the metabolic research is in rodents and cell culture; a single small human study from 2003 is the entire clinical basis.

Evidence last reviewed: August 2026

What the science says

  • Cholesterol lowering Limited evidence

    One 8-week study gave 400 mg/day of naringin to 30 hypercholesterolaemic and 30 normal subjects and reported 14% lower total cholesterol and 17% lower LDL in the hypercholesterolaemic group, with no change in healthy controls. There was no placebo group and the finding has not been replicated in over two decades.

  • Metabolic syndrome and blood glucose Limited evidence

    A review of citrus flavonoids concluded that the evidence for naringin and naringenin in metabolic syndrome comes overwhelmingly from animal models, with human data described as scarce.

  • Antioxidant enzyme activity Limited evidence

    The same 2003 study reported increased erythrocyte superoxide dismutase and catalase activity, a laboratory marker with no demonstrated clinical meaning on its own.

Dosage & safety

Studied doseThe only human trial used 400 mg/day for 8 weeks. Commercial capsules commonly supply 250–500 mg, based on that study rather than any dose-ranging work.
SafetyNaringin is the compound behind the grapefruit-drug interaction: it inhibits intestinal CYP3A4 and OATP transporters, which can raise blood levels of statins, calcium channel blockers, some immunosuppressants, certain benzodiazepines and many other drugs. Anyone on prescription medication should treat concentrated naringin as they would grapefruit juice and check with a pharmacist. Avoid in pregnancy for lack of data.

Scientific references

Where to buy

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