Grapefruit Seed Extract Safety


There are several articles on the internet indicating problems with grapefruit seed extract. (In truth, it’s just one article that’s been re-circulated several times). The key points of the article are:
  • Grapefruit seed extract is highly processed
  • It’s not natural
  • It’s not organic
  • The extraction process uses toxic solvents such as hexane
  • The extraction process converts the natural phenolic compounds found in grapefruit into synthetic quaternary ammonium compounds such as benzethonium chloride, a highly toxic synthetic germicidal
  • It doesn’t work
  • All of the so called benefit comes from chemical preservatives added to grapefruit seed extract.

In fact, there is some truth to the claims, but, as they say, the devil is in the details.

Is it a highly processed product? Judge for yourself; here is the process.

The extract is prepared by grinding grapefruit seeds and pulp into a fine powder. The powder is dissolved into purified water and distilled to remove fiber and pectin. The distilled slurry is spray dried at low temperatures forming a concentrated grapefruit bioflavonoid powder. This concentrated powder is dissolved in vegetable glycerin and heated. Food grade ammonium chloride (An acidic substance found naturally in the stomach) and ascorbic acid are added. This mixture is heated under pressure where it undergoes catalytic conversion using natural catalysts, including hydrochloric acid and natural enzymes. The slurry is then cooled, filtered, and treated with ultraviolet light. Residual ammonium chloride in the final product is between 15 and 18%; residual ascorbic acid is between 25 and 35 mg/kg. There is no residue of hydrochloric acid in the final product. In the United States, standardized GSE contains 60% grapefruit extract materials and 40% vegetable glycerin.

As to not being natural or organic and, that depends on your source and your definition. Some brands definitely fit that definition. Other sources use organic grapefruit as the source ingredient and use natural solvents in the extraction process as outlined above. They qualify as organic.

And as for the complaint that the process produces synthetic quaternary ammonium compounds. That sounds bad unless you realize that B-vitamins such as choline and acetylcholine are quarternary ammonium compounds. In fact, the active component in grapefruit seed extract is diphenol hydroxybenzene, which is similiar to benzethonium chloride, but not the same. Statements that grapefruit seed extract contains traces of benzethonium chloride are inaccurate.

But the real statement that needs to be addressed is that grapefruit seed extract doesn’t work and that all its benefits come from added preservatives. And for that statement the articles rely primarily on a single report

  1. From the Institute of Pharmacy, Ernst Moritz Arndt University, Greifswald, Germany. Woedtke T, Schluter B, Pflegel P, Lindequist U, Julich WD. 1999. Aspects of the antimicrobial efficacy of grapefruit seed extract and its relation to preservative substances contained. Pharmazie 54:452-6.

Not to be dismissive, but although the Ernst Moritz Arndt University has a long history, it is not ranked in the top 500 Universities in the world. More importantly, the results of this study are countermanded by dozens of other studies published over the last 30 years proving the exact opposite – that grapefruit seed extract does indeed have strong anti-pathogenic properties. For example:

A study by the USDA found it effective against three animal viruses: The United States Department of Agriculture, Greenport, New York, USA. Citricidal Effective Against Three Animal Viruses: Foot and Mouth Disease (FMD), African Swine Fever (ASF), Swine Vesicular Disease (SVD).

  1. Testing was conducted by the U. of Georgia, in Athens, GA, to evaluate grapefruit seed extract in tests against E. Coli, Salmonella sps, and Staph aureus. Roger Wyatt, Ph.D., and Microbiologist for the U. of GA, reported, "Our studies indicate excellent potential for these products (GSE). ...The toxicological that I have reviewed indicated that this product and the active ingredient poses very low toxicity. As you know this is important because most disinfectants that are currently used in either animal or human environments have moderate to high toxicity and extreme care must be exercised when these products are used. The lack of any significant toxicological properties of (GSE) is also impressive when one views the efficacy data where extemely small concentrations of the product can be used with marked beneficial results."
  2. And in fact, grapefruit seed extract is used in a number of hospitals around the world for its antimicrobial properties both to sterilize hospital laundry and carpets, and in higher concentrations, to disinfect operating rooms.

Bottom line: it is for the above reasons that, at least at this time, that Jon Barron still recommends the use of grapefruit seed extract.


THE ABOVE STATEMENTS HAVE NOT BEEN EVALUATED BY THE FOOD AND DRUG ADMINISTRATION. THIS INGREDIENT IS NOT INTENDED TO DIAGNOSE, TREAT, CURE, OR PREVENT ANY DISEASE.