Grapefruit Seed Extract

Grapefruit seed extract (GSE), also known as citrus seed extract, is a liquid derived from the seeds, pulp, and white membranes of grapefruit. Self-made natural GSE processed in the laboratory without solvents or synthetic agents is prepared by grinding the grapefruit seed and juiceless pulp, then mixing with glycerin. Commercially available GSE sold to consumers are made from the seed, pulp, glycerin, and synthetic preservatives all blended together. Grapefruit seed extract is sold as a food supplement and used in cosmetics because it is a claimed natural antimicrobial.

An early proponent was Dr. Jacob Harich (1919–1996). A long time promoter of GSE was Aubrey Hampton, the founder of Aubrey Organics. Some marketers of GSE affirm this extract to be a safe, natural, and an effective preservative. This extract has been stated by some practitioners of alternative medicine to possess antibacterial, antiviral, and antifungal properties. It has been recommended by some nutritionists for the treatment of candidiasis, earache, throat infections, and diarrhea. GSE is promoted at health food shops and on the internet.

There are conflicting scientific demonstrations of the efficacy of GSE. Suspicions about the true nature of the active compounds in GSEs arose when synthetic additives were found in commercial products. Suspected counterfeit grapefruit seed extracts were adulterated with synthetic preservatives. When preservatives were not present in some of the extracts, laboratory tests found the natural extracts had no natural antimicrobial attributes of their own. Some manufacturers of GSE have stated that their extract has compounds nearly identical to benzethonium chloride, but a 2001 study supervised by chemist G. Takeoka has documented that commercial GSE preparations contain the synthetic compound benzethonium chloride that could not have been made from GSE.