The NHS provides a very in-depth article on this (their health information is generally top notch). I would recommend giving it a read: https://www.nhs.uk/news/

The NHS provides a very in-depth article on this (their health information is generally top notch). I would recommend giving it a read: https://www.nhs.uk/news/medication/prescription-drugs-and-grapefruit-a-deadly-mix/ https://www.nhs.uk/news/medication/prescription-drugs-and-gr.... In the article they state: > How much grapefruit is too much grapefruit? > The researchers report that furanocoumarins are present in all forms of grapefruit (freshly squeezed juice, frozen concentrate and whole fruit). > One whole grapefruit or 200ml of juice is sufficient to cause enough of an increase in the concentrations of active drugs to have an effect on the body, and therefore could cause side effects. I presume this would hold for other "bitter citrus" as well. ——————————————— The listed potential health effects are quite significant: > - Torsade de pointes (a form of abnormally rapid heartbeat that starts in the lower chambers of the heart, which can increase the risk of sudden death) > - Complete heart block (where there is no transmission of the electrical pulses between the upper and lower chambers of the heart that are needed to make it beat) > - Rhabdomyolysis (breakdown of muscle fibres that leads to the release of muscle fibre contents, including myoglobin which breaks down into substances that can damage the kidney) > - Nephrotoxicity (kidney damage) > - Myelotoxicity (damage to the bone marrow) > - Venous thrombosis (blood clot)