Pomelo Interactions

Pomelo, like grapefruit, contains furanocoumarins that inhibit the intestinal CYP3A4 enzyme. Red yeast rice's active constituent, monacolin K, is chemically identical to the statin lovastatin, which depends on CYP3A4 for its breakdown. When pomelo blocks that enzyme, more of the monacolin K reaches the bloodstream, amplifying the dose-dependent statin-type risks of muscle injury and, rarely, liver enzyme elevation. Because furanocoumarin inhibition can persist for days, the effect is not reliably avoided by taking the two at different times of day.

Pomelo contains furanocoumarins that inhibit intestinal CYP3A4 and P-glycoprotein, the systems that limit how much tacrolimus is absorbed. A documented case in a renal transplant patient showed pomelo consumption raised tacrolimus blood levels, and tacrolimus has a narrow therapeutic window where small swings can cause kidney or nervous-system toxicity, or under-immunosuppression and rejection.

Pomelo (Citrus maxima) contains furanocoumarins that inhibit intestinal CYP3A4, the enzyme that breaks down simvastatin during first-pass absorption. With that enzyme suppressed, more simvastatin reaches the bloodstream, raising the risk of muscle-related side effects. This is the same mechanism behind the well-established grapefruit-simvastatin interaction, since pomelo is the parent species of grapefruit and shares its furanocoumarins.