Grapefruit Seed Extract

GSE has demonstrated its ability to kill or inhibit the growth of a wide array of potentially harmful bacteria, fungi, viruses and protozoan parasites.” (Sachs, 1997). A study by the Bio Research Laboratories of Redmond, Washington compared chlorine bleach to GSE and found that GSE was superior to chlorine bleach at killing organisms like E. coli. and Salmonella typhi. More and more studies like this are proving GSE more effective than common disinfectants like alcohol and bleach. Some farmers are beginning to use it as a way to extend the shelf life of their fruits and vegetables instead of chemical sprays.

The uses for GSE are diverse and luckily it is more ecologically sound than some of the products that it could potentially replace. Veterinarians have used it to cure ear infections in cats and dogs, purify raw meat given to pets, and treat Giardia. It is becoming more popular as a disinfectant in hospital laundries and for household use as well. The potential for human use is also extensive and exciting. Its properties could potentially treat dandruff, sore throat, nausea, cold sores, and the list goes on and on. Its use as a water purifier is still being tested, but campers may want to add it to their packs to use as a first aid spray, food rinse, and biodegradable dish soap.

As those of you who have tried to take this product internally can attest to, the taste is quite potent, so just make sure you follow the recommended dilutions.


  • “The Authoritative Guide to Grapefruit Seed Extract, “Allan Sachs D.C., C.C.N., LifeRhythm, 1997.
  • Gale Encyclopedia of Alternative Medicine, website:

There are many herbs and essential oils that kill enterococcus, staphylococcus and other bacteria which antibiotics are unable to treat. One of the most popular is grapefruit seed extract, or GSE, made from the seeds and connecting tissue of citrus fruit. In the October 1996 edition of his Alternatives newsletter (Mountain Home Publishing, 1201 Seven Locks Road, Rockville, MD 20854), David G. Williams, D.C., described an elderly woman with VRE who was successfully treated for five days with a product that contains 100 mg grapefruit seed extract, 200 mg Artemisia annua (annual wormwood or sweet Annie) and 200 mg Echinacea angustifolia, 1 capsule 3 times daily. After repeated cultures showed her to be free of the VRE infection, two other VRE patients received the same treatment. Because conventional medicine has nothing to offer VRE patients, this is exciting news—but, as Williams explained, it isn’t news you’re likely to read outside of his publication, for the physicians using this unapproved, unconventional therapy have no interest in creating a medical controversy by reporting their results. “If you have any upcoming surgery or hospital stays, or if you work in a hospital setting,” he wrote, “I would suggest keeping some of this [type of]product around. I would also consider pre-dosing 3 or 4 days prior to any surgery, as well as taking the product for a week or so following the procedure.”

Grapefruit Seed Extract: Stops Strep, Staph, Candida, Parasites, Herpes, Salmonella.

Grapefruit seed extract, (gse), in a glass of water could put a stop to the flu or a sore throat. It could also help control Candida or gingivitis, and it’s been known to banish athlete’s foot in a single application. It is highly effective against diarrhea and food poisoning, it could rid you of worms or parasites, it can even stop you going down with cholera or dysentery when traveling abroad. it is more potent than tea tree oil. The best news is that it is natural, inexpensive and non toxic.

GSE has been shown to inactivate viruses, yeasts, fungi, parasites and worms, as well as bacteria. What’s in there that makes it work really isn’t known,” Dr.: Leo Gallard has been prescribing GSE to New York patients for over 7 years, told Natural Health Magazine, “There’s just something unique about this particular substance.

Ionescu, Kiehl, Wichmann-Kunz, Williams, Baum and Levine. Oral Citrus Seed Extract in Atopic Eczema: In vitro and in vivo studies on Intestinal Microflora” Journal of Orthomolecular Medicine Volume 5. No 3, 1990 The Third Opinion, Volume 1 Petaluma CA 94952

Grapefruit seed extract (GSE) has a proven track record as a powerful and non-toxic antimicrobial agent with a broad spectrum of activity. Research has demonstrated that grapefruit seed extract can be effective in treating candidiasis, including candida albicans vaginitis. Researchers have also had positive results using GSE as an antimicrobial on food and as a deep cleanser for skin. Added to toothpaste and mouthwash, GSE may protect against bacterial infection in the mouth.


Grapefruit seed extract can be used in a variety of ways to boost protection against pathogens. Some asthmatics have used the extract in nebulizers, with great success, in order to  revent against lung and bronchial infections.


Refer to dosage information on labels. Be careful not to confuse GSE with “grape seed extract.”

MAXIMUM SAFE LEVEL: Not established


Grapefruit seed extract is not associated with any side effects, drug interactions, or contraindications. However, a number of medications should not be taken with grapefruit juice itself. These include certain immunosuppressants, cholesterol-lowering drugs, and antihistamines – if in doubt consult a physician. Furthermore, when taken as recommended it does not destroy the ‘healthy’ bacteria that reside in the gastro-intestinal tract.

A partial list of laboratories that have tested grapefruit seed extract for its effectiveness since 1974

  • ABC Research, Gainesville, Florida
  • Abcom Chemie Co., Seoul, Korea
  • Alpha Chemical and Biomedical Labs, Petaluma, Ca
  • AquaLandis Inc., Canada
  • Analytical Chemical Services Inc. Columbia, Maryland
  • Association of Consulting Chemists and Chemical Engineers Bioassay Systems Corp., Woburn, Massachusetts
  • Bio-Research Laboratories, Redmond, Washington
  • Brigham Young University, Provo, Utah
  • British Columbia Research Corp., Vancouver, B.C., Canada
  • Coopemontecillos Division Pesca, San Jose, Costa Rica
  • Daiwa Kasei Chemical, Tokyo, Japan
  • Department of Health and Human Services, FDA, Washington D.C.
  • Department of Food Technology, Gycongsang Nat’l University, Chinju, Korea
  • East Chilliwack Agricultural Co-op, Chilliwack, B.C., Canada
  • Great Smokies Labs, Asheville, North Carolina
  • Florida Department of Agriculture, Tallahassee, Florida
  • Hazelton Labs, Madison, Wisconsin
  • Hilltop Research Inc., Miamiville, Ohio
  • ImuTech Inc. Huntington Valley, Pennsylvania
  • Indonesian Government at the Nat. Center for Fisheries, Jakarta
  • Institut Pasteur, Paris, France
  • Irvine Analytical, So. San Francisco, California Journal of Food Science
  • Journal of the Korean Agricultural Chemical Society Journal of Orthomolecular Medicine
  • Lancaster Laboratories, Lancaster, Pennsylvania
  • Northview Pacific Labs, Berkeley, California
  • Silicon Valley Chemlab Inc., Tampa Florida
  • U.S. Dept. of Agriculture, Hyattsville, Florida
  • United States Testing Co., Hoboken, New Jersey
  • Universidad Autonoma de Nuevo Leon, San Nicolas de los Garza, Mexico
  • Universidad National Mayor de San Marcos, Lima, Peru
  • University of California, Davis, California
  • University of Florida, Food Services Dept., Gainesville, Florida
  • University of Nebraska
  • University of So. Florida, Dept. of Biology, Tampa, Florida
  • University of Texas Medical School, Galveston, Texas
  • Valley Microbiology Services, Palo Alto, California
  • Weston-Gulf Coast Laboratories, University Park, Illinois


  • Acute Oral Toxicity: LD50 over 5,000 mg/kg of live weigh.
  • Chronic Toxicity: (Acute oral with continuous feeding and reproduction study for 24 months.) LD50 2,500 mg/kg of live weight (Rats and Guinea pigs).
  • Acute Oral Toxicity: (Continuous feeding study with fishmeal for 12 mo’s) LD50 5000 mg/kg of live body weight(Adult rats, 12 months): LD50 400 mg/kg of live weight (newborn rats)
  • Dermal Toxicity: Not a primary skin irritant and is non-corrosive.
  • Carcinogenicity: 12-month tests in mice show no carcinogenic effect. 24-month tests in rats show no carcinogenic effect.
  • Long-term Inhalation Study: Closed chamber exposure for 8 hours a day, 5 days a week for 90 days – no effect at 100 – 150 mg/m3 air Dermal Toxicity Carcinogenicity 2 year studies with rats and mice. No carcinogenic, toxicity or systemic effects seen.
  • Eye Irritation: Full strength – severe irritation with slight corneal iris injury. 0.5%, 1%, and 2% concentrations produce irritation and moderate erythema.
  • Human Patch Studies: 1% and 2% concentrations produced no irritation or sensitization. 3% concentration produced very mild irritation by allergic humans.
  • Grapefruit Seed Extract: The data presented herein is based on experiments and information believed to be accurate and reliable. However, no warranty is made, either expressed or implied, regarding the accuracy of the results to be obtained from the use of such data. We will assume no responsibility for the results or performance in products and applications over which we have no control.
  • Shelf life: After 6 years the oldest batch of extract still on hand tests every bit as potent as a current batch. Grapefruit seed extract is extremely stable. It does not require a “best if used by…” date. The product will remain stable for an indefinite period, as long as it is not contaminated in some way. Grapefruit seed extract is best stored in a cool dry place (Refrigeration is not necessary). Keep Tightly Closed and Away From Children.