Grapefruit see extract (GSE), also known as citrus seed extract, is a liquid derived from the seeds, pulp, and white membranes of grapefruit. While there has been no scientific demonstration of efficacy, this extract has been claimed by some practitioners of alternative medicine to possess antibacterial, antiviral, and anti-fungal properties. Indeed, it has been recommended by some nutritionists for the treatment of candidiasis, earache, throat infections, and diarrhea. Some natural food retailers claim this extract to be a safe, natural, and an effective preservative. Recent studies have identified synthetic preservatives in commercial grapefruit seed extracts. When preservatives were not present in some of the extracts, laboratory tests found the natural extracts to have little or no natural antimicrobial attributes of their own. An early proponent was Dr. Jacob Harich (1919–1996). Some of the manufacturers of GSE have claimed that their extract has compounds nearly identical to benzethonium chloride but a 2001 study overviewed by chemist G. Takeoka and run by fellow researchers has documented that commercial GSE preparations contain the synthetic compound benzethonium chloride that couldn't have been made from GSE. Nonetheless, promoters from book authors to cosmetic companies continue to affirm that citrus seed extract has strong natural healing properties despite lack of scientific or clinical evidence.