I've heard that grapefruit juice can interact with medications because it inhibits an enzyme that breaks down drugs in the body. Do any supplements interact the same way with drugs?

Answer:

Yes, it's well-known that grapefruit juice can interact with many medications, including certain cholesterol-lowering statin drugs, blood pressure drugs, antihistamines, and sedatives. One of the ways grapefruit does this is by inhibiting CYP3A4, an enzyme in the liver and intestine that helps metabolize (break down) approximately 50% of all medications. This can lead to potentially excessive blood levels of these medications, increasing their effects and side effects.

Many supplements can also inhibit (and in some cases, activate) CYP3A4 and interact with many of the same medications.

Supplements that may inhibit CYP3A4 and increase blood levels and possible side effects of drugs broken down by this enzyme:

• Black pepper extract (piperine or Bioperine) — a bioavailability enhancer in some curcumin and CoQ10 formulas
• Cat's claw
• CBD Oil (cannabidiol)
• Elderberry extract
• Ginger
• Goldenseal/Berberine
• Green tea
• Kava
• Kratom
• Resveratrol
• Schisandra
• Tribulus terrestris
• Turmeric/curcumin

Supplements that may induce CYP3A4 and decrease the activity of drugs broken down by this enzyme:

• Echinacea
• Ginseng
• Quercetin
• St. John's wort

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Be aware that some supplements are also metabolized by CYP3A4 and may be affected by grapefruit juice or other supplements that inhibit or activate this enzyme. These supplements include:

• CBD (cannabidiol)
• Red yeast rice