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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.

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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.

How to take it

TimingTiming does not matter.
With food?With food.
Worth knowingIf any of your medicine labels says to avoid grapefruit, that warning applies to concentrated naringin too.

Interactions

With medications

  • simvastatin, atorvastatin and other CYP3A4 statins

    Naringin inhibits intestinal CYP3A4, raising statin levels and the risk of muscle damage. do not combine

  • felodipine, nifedipine and other calcium channel blockers

    Raised drug levels can cause excessive blood pressure drops, flushing and headache. avoid concentrated naringin

  • cyclosporine and tacrolimus

    Raised blood levels increase the risk of toxicity. do not combine without medical supervision and level monitoring

  • midazolam, triazolam and other CYP3A4 benzodiazepines

    Stronger and longer sedation than intended. avoid the combination

  • fexofenadine, aliskiren and other OATP substrates

    Naringin blocks the transporter that absorbs them, so the drug works less well. separate by at least 4 hours, or avoid

Well-established interactions only — this is not a complete list. Always tell your doctor and pharmacist what you take.

Frequently asked questions

Does naringin lower cholesterol?

Naringin has limited evidence for cholesterol: one 2003 study without a placebo group reported 14% lower total cholesterol and 17% lower LDL with 400 mg/day in hypercholesterolaemic people. The finding has not been replicated in over two decades.

Does naringin interact with medications like grapefruit?

Yes, naringin is the compound behind the grapefruit-drug interaction: it inhibits intestinal CYP3A4 and OATP transporters. Do not combine naringin with simvastatin, atorvastatin, cyclosporine or tacrolimus, and avoid it with calcium channel blockers and CYP3A4 benzodiazepines such as midazolam.

Does naringin help with blood sugar or metabolic syndrome?

The evidence for naringin in metabolic syndrome and blood glucose comes overwhelmingly from animal models, and human data are scarce. Naringin's evidence grade for these uses is limited.

How much naringin should I take?

The only human naringin trial used 400 mg/day for 8 weeks, and commercial capsules of 250–500 mg are based on that study, not dose-ranging work. If any of your medicine labels says to avoid grapefruit, that warning applies to naringin too.

Scientific references

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