According to a study published in the Journal of Alternative and Complementary Medicine, grapefruit-seed extract is effective in killing over "800 bacterial and viral strains, 100 strains of fungus, and a large number of single and multi-celled parasites."
Developing evidence suggests that a grapefruit seed extract can decrease constipation, gas, and stomach discomfort possibly due to changes in intestinal bacteria, in people with eczema
Drug interactions with grapefruit juice are possible. Before adding grapefruit seed extract to your list of natural medicines, check with your healthcare provider if you take medications.