Some people take grapefruit seed extract to treat bacterial, viral and fungal infections. It can also be used topically as a facial cleanser, to treat skin irritations, as a vaginal douche for yeast infections, as a ear and nose rinse to treat infection, as a gargle for throat pain and as a mouthwash to prevent gingivitis. Grapefruit has been found to interact with some medications, but what about grapefruit seed extract?
Major Drug Interactions
The following medications should not be taken with grapefruit seed extract as they can cause major interactions, including changing how the body absorbs the medication and making side effects of the medication more likely: Artemether, Buspirone, Carbamazepine, Carvedilol, Cisapride, Clomipramine, Cyclosporine, Dextromethorphan, Estrogens, Etoposide, Itraconazole, Fexofenadine, Methylprednisolone, Praziquantel, Quinidine, Scopolamine, sedatives, Sildenafi and Terfenadine. Medications that are processed by the liver and high blood pressure medications also interact with grapefruit seed extract.
Moderate Drug Interactions
The following drugs have a moderate interaction when taken with grapefruit seed extract, which means that caution should be used when taking the two together: caffeine, Erythromycin, Losartan, Saquinavir, Theophylline and Warfarin. The dosage of these medications may need to be changed when taken with grapefruit seed extract and for some there is not enough information to confirm a major drug interaction.
Pregnancy and Breastfeeding
The effects of grapefruit seed extract on pregnancy and breastfeeding is not known. There is simply not enough information to know whether it is safe to consume grapefruit seed extract during pregnancy or while breastfeeding so it is advised that women avoid it during this period. There does not seem to be a problem with consuming grapefruit normally as food or drink.
There is some evidence that drinking excess amounts of grapefruit juice can increase the risk of breast cancer by 25 to 30 per cent. This has to do with the way grapefruit and oestrogen interact. There is no information on grapefruit seed extract but, in order to be safe, it should not be used excessively, especially in those who are at greater risk for breast cancer.