A. Jacob Harich and others developed grapefruit-seed extract at the University of Florida in Gainesville to protect fruit and vegetables from mold damage. The active ingredients in GSE appear to be an assortment of chemicals known collectively as "quaternary ammonium" compounds. Quaternary ammonium compounds are well known as synthetic antiseptics but are also found in nature. For instance, the essential B-vitamins thiamin and choline are quaternary ammonium compounds.
GSE is a broad spectrum antimicrobial with proven ability, at least in the test tube, to kill or inhibit the growth of a wide array of potentially harmful bacteria, fungi, viruses, and protozoan parasites. Some quaternary ammonium compounds are toxic to animal life, but when used at the correct concentration, GSE appears to be both antimicrobial and nontoxic. Research published in The Journal of Alternative and Complementary Medicine in June of 2002 reports that one brand of liquid GSE, Citricidal, injured human skin cells even when diluted one part in 256. A more dilute solution, one part in 512, was still antimicrobial but nontoxic. So, for internal use, dilute to one part in 512, about one-quarter teaspoon of Citracidal in 1 pint of water, the equivalent of two tablets or capsules. The article also describes the mechanism of GSE's antibacterial activity, which is similar to that of many antibiotics, namely disruption of the protective cell wall and membrane of bacteria.
Combining GSE with certain oils, such as geranium oil and tea tree oil, appears to enhance its antimicrobial activity. The journal Burns in December of 2004 reports that a combination of GSE and geranium oil was more effective than GSE alone against antibiotic resistant Staphylococcus aureus, one of the troublesome "superbugs" that has developed from the overuse of antibiotics over the past 50 years.
Part of GSE's antimicrobial action is due to its high acidity, about the same pH as your stomach juices. Stomach acid is our frontline defense against infectious organisms, but only the stomach lining can withstand this level of acidity. Just as stomach juices will harm the mucus membranes outside the stomach, undiluted GSE will do the same. GSE is a very powerful remedy that should never be used internally at full strength. Because of the high acidity, GSE can cause severe eye irritation and should never be used in the eyes.
Claims are made that GSE can be used to kill head lice by mixing it with your shampoo (one part in three) and using a shower cap to keep the shampoo/GSE mix on your scalp for 20 minutes. More than one application may be necessary. Another possible use is to clear up herpes outbreaks, daily dabbing on a one-to-nine dilution.
GSE has been found to be an effective disinfectant in both human and veterinary hospitals. As a cleaning agent around the house, GSE can be used for disinfecting countertops and cooking utensils. Rub fruits and vegetables with a solution of 10 drops of GSE in 1 quart of water to kill bacteria and remove pesticide residues on fruits and vegetables.
