Possible side effects of grapefruit seed extract include nausea, vomiting, a swollen or painful tongue, and burning in the mouth, stomach or throat, according to Allina Health. Patients who experience allergy symptoms such as rash, hives or chest tightness after consuming this supplement should seek immediate medical care.
Patients who have had organ transplants and are taking medications such as cyclosporine should talk with their doctors before taking grapefruit seed extract, since it may interact negatively with these medications, explains Allina Health. Patients should also seek a doctor's advice before taking grapefruit seed extract when pregnant or breast feeding.
Grapefruit seed extract is taken orally to fight bacterial, viral and fungal infections, including yeast infections, explains WebMD. Some patients use it as a vaginal douche to fight vaginal yeast infections or as a nasal rinse to prevent ear infections. Vaporized grapefruit seed extract is used to treat infections of the lungs. In its liquid form, it is sometimes used as a mouthwash or throat gargle, or to cleanse acne-prone skin, explains Allina Health. Other names for the extract include Citrus grandis, rutaceae and Citrus paradisi. Patients are advised to follow dosing instructions on the label or to speak with their health care provider to determine how much grapefruit seed extract to take for a specific ailment.