grapefruit seed extract

Grapefruit seed extract (GSE) is a liquid extract derived from the seeds, pulp, and white membranes of grapefruit (Citrus paradisi). It is typically prepared by grinding these components and mixing them with glycerin. GSE is marketed as a dietary supplement and is also used in cosmetics. Its composition includes phytochemicals such as flavonoids (e.g., naringenin), ascorbic acid (vitamin C), tocopherols (vitamin E), citric acid, limonoids, sterols, and minerals. It is proposed to possess broad-spectrum antimicrobial (antibacterial, antiviral, antifungal, antiparasitic) properties, primarily by disrupting microbial cell membranes. Additionally, it is believed to have antioxidant and cytoprotective effects, and may support gastrointestinal health by promoting healthy microflora and gut ecology. Some studies suggest it may activate prostaglandin, nitric oxide, and sensory nerve pathways for gastroprotection. However, there is a notable lack of robust human clinical trials, and concerns exist regarding the adulteration of commercial GSE products with synthetic antimicrobials, which may be responsible for some of the observed effects. Potential drug interactions due to its flavonoid content are also a consideration.

Brand names

NutriBiotic GSECitricidalParaMycrocidin

Other names

GSEcitrus seed extractGFSE