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Grapefruit Seed Extract - The Ultimate Antimicrobial?

by Dorothy Cronin(more info)

listed in infections and inflammation, originally published in issue 23 - November 1997


In November 1996, while on holiday in Ireland, I spent an evening with a friend, a qualified nurse and a practising aromatherapist and reflexologist. As always, in her company, talk turned to the application of alternative remedies to support conventional medical practice. She handed me a small flyer which spoke of a new remedy which had been gaining increased credibility in America, and which was now available in Ireland. It spoke of an incredibly broad spectrum of applications: of anti-microbial, anti-bacterial, antifungal, antiseptic, anti-parasitic properties; of low toxicity, low cost, and of biodegradability. It spoke of a totally naturally occurring, and naturally processed food supplement, which has been available and untapped on this planet for at least 300 years, since the first grapefruit trees were discovered and identified on the island of Barbados. The product was grapefruit seed extract, and my friend was beginning to test out its claims.

On my return to the UK, I sought in vain for a retailer who had even heard of this wonder product, and, in desperation, phoned the Irish distributor who sent me a bottle and a book describing the properties, entitled The Healing Power of Grapefruit Seed. Book and bottle arrived in mid-November, the busiest time of my working year, and a time at which I cannot afford either holidays or sickness. That evening, I came home from work with the makings of the flu which had been laying waste my colleagues, and keeping people who were never ill away from work of upwards of a fortnight. In one sitting I read the book and put the Grapefruit Seed Extract (GSE) to the test. I made up my normal cold remedy – honey, cider vinegar, hot water – and laced it with 10 drops of GSE. I also took 2000mg of vitamin C, and 2 Gelsemium 6 potency, which I have always found useful for the early abatement of flu, but, in spite of my precautions, I had very little expectation of escaping. An early night did nothing to ease my discomfort. I tossed and turned and snuffled and dozed into the early hours in increasing discomfort, concerned now that the infection would not end up on my chest and aggravate my asthma. About 3.00am I woke from a feverish doze pouring with perspiration and feeling decidedly unwell, and very dehydrated. After a drink of water and a cool sponge-over, I went back to bed full of apprehension, to fall into a dreamless and restful sleep, only broken by the sound of the alarm clock at 7.00. I felt rested, clear headed, and had no sign of the previous night’s fever, and only the remains of soreness in my nose and throat. The event was unprecedented, and I was, in fact, the only member of a 60 strong staff to escape the flu, and the resultant revolting cough. In fact, over the busy period, November to April, I fought off two more potential bouts of the particularly virulent flu which raged across the West Midlands, eventually succumbing to a mere head cold when I went on holidays unprepared in May!


Grapefruit has been known in this country since the 17th century when it was identified by botanists on the island of Barbados. The anti-oxidant effect of citrus has been known for even longer. However, the discovery of the additional properties of Grapefruit Seeds was only made as recently as 1980.

Dr Jacob Harich, a keen gardener, as well as a physician, an Einstein Laureate physicist, and an immunologist specialising in the investigation of natural remedies, noticed that grapefruit seeds in his compost heap did not rot. His curiosity piqued, he decided to take a closer look, and discovered a substance concealed in the grapefruit seeds that appeared to be more effective, and at the same time less harmful, than any known antibiotic. Research subsequently uncovered a broad range of efficacy. The extract from the seeds was found not only to inactivate viruses, but also yeasts, other fungi and parasites.


The extract contains primarily bioflavonoids and glycosides in the form of naringin (naringenin rutinosid), isosacuranetin (didymin), neohesperidin, hesperidin, dihydrocampherol glycoside, poncirin, quercetin glycoside, campherol glycoside, apigenin rutinoside, rhoifolin, heptamothoxyflavone, nobiletin, as well as several proteins.

Research indicates that the active ingredients of the extract disorganise the cytoplasmic membrane of the pathogen, thereby preventing the uptake of amino acids. At the same time there is a leakage of the cellular content with low molecular weight through the cytoplasmic membrane. The pathogen is inactivated and dies. The time required is normally shorter than, or, at worst, equal to that of most comparable preparations for eliminating micro-organisms.

It has been proven highly effective against a broad spectrum of germs and fungi including E.Coli, Candida, Staphylococcus, Streptococcus, Salmonella, Pseudominas, Lactobacillus, Klebsiella, Shigella, Legionella, Chlamydia, Helicobacter, Herpes and Giardia lamblia

Therapeutic Applications

GSE is used internationally in many ways.

  • In Thailand, a water projects uses GSE as its main purification agent. 350 gallons to 1 million gallons of water will reduce coli bacteria to 1 per 100ml. (200 per 100ml is officially considered acceptable).
  • In South America, GSE is used to purify many public swimming pools. Its application is preferable to the use of chlorine because it is not decomposed by UV rays, gives off no harmful vapours, does not cause skin irritation, does not evaporate if the temperature rises, is active against a range of fungi, including athletes’ foot which flourish in the environs of a swimming pool, and leaves no toxic residues in the environment.
  • In farming GSE has proven extremely effective. A Danish pig farmer reported losses due to Porcine Reproductive Respiratory Syndrome of 16 out of every 30 piglets born. GSE successfully eliminated this loss, and doubled his profits. It is also used in the treatment of mastitis in cows in preference to antibiotics. In Peru, deaths of alpacas from various infectious diseases were reduced from 50% to 2% by the substitution of GSE for conventional vaccination and antibiotics.
  • In hospitals in the USA it is used in the cleaning of bed linen and carpets and was endorsed by Jerry Skidmore, manager of Laundry Operations in the Florida Hospital as giving “complete protection from the fungal and bacterial infections that can be associated with linen”. This result is regularly tested and proven. In higher concentrations GSE is used for sterilising and disinfecting operating rooms and medical equipment such as inhalers. In Sao Paulo, Brazil, the extract was reported as 100% effective as a post-operative disinfectant, attacking only the bacteria, and not the skin. This compared with 98% effectiveness for the usual measures, and 72% for alcohol.
  • In treatment of Candida, Dr Leo Galland of New York, who has prescribed GSE for the past 7 years has reported only 2 failures out of 297 cases. The bonus attaching to the use of GSE is that it can simultaneously detoxify the system of other fungi and bacteria often accompanying Candida. It should, however, always be used within the framework of a comprehensive programme, and under competent direction. Without the necessary attendant changes to diet and lifestyle, the initial cure is unlikely to be maintained. It is also important to apply the remedy in increasing doses, starting from a low base, to avoid Herxheimer’s reaction when the fungi start to die off.

The preservative properties, combined with total absence of toxicity make GSE a superb household cleanser across the whole spectrum from floors to food. The same properties offer opportunities for its application in any area where hygiene is of paramount importance such as food retail outlets and catering establishments.

The attraction of this broad spectrum product to the practitioner is that it allows him to tackle several different problems with the same remedy, often yielding the result, even if it has not been possible to come to a comprehensive diagnosis. Additionally, it does not compete with existing remedies, but supports their activity.

Like all products new to the market, “proof of the pudding is in the eating”. As my casebook increases in size, and clients return for replacement bottles, and additional information, I become more and more convinced that this is Nature’s gift to us for the new millennium.


The Healing Power of Grapefruit Seed by Shalila Sharamon & Bodo J Baginski        Lotus Light Shangri-La

Other publications discussing the properties of GSE include “Beyond Nutrition”, “Mothering”, “The Third Option”, “Alternative Medicine Digest”, “Natural Health” (Magazines), and “Coping with Candida”, Shirley Trickett; “The Allergy Problem”, Vickey Rippere; “Parasites – the Enemy Within”, Dr Hanna Kroeger; “The Cure for All Cancers – 100 Case Histories”, Dr Hulda Regehr Clark;

For more information contact:

Holistic Alternatives, 10 Whitworth Drive, Randlay, Telford, TF3 2NN or phone or fax on 01952 593193.

The Ideal Anti-Microbial?
GSE has many of the characteristics of an ideal anti-microbial.
  • Broad spectrum – Research shows that GSE is effective against approximately 800 bacteria and virus strains, 100 strains of fungus and a large number of single cell parasites, far exceeding that of any currently known anti-microbial.
  • Powerful and effective – GSE develops its antimicrobial activity with an average concentration of 1,000 parts per million – corresponding to about 8 drops in a glass of water. Research by an international research team compared the performance of GSE on 770 strains of bacteria and 93 fungal strains with 30 effective antibiotics and 18 fungicides, and found that GSE performed as well as all tested agents.
  • Non-toxic – The non-toxic effect of GSE may be recognised in the effect on a drunken agricultural worker in Peru who, as the result of a prank, accidentally ingested 4 fl oz of the extract. Apart from clearing out all the parasites in his body (of which there was a great number), he suffered no ill effects. Research indicates that a person weighing 180lbs (approx. 13 stone) would need to ingest about 5.5 pints of a 50% solution of GSE in order to become severely poisoned.
  • Non-weakening to the immune system – GSE can be used in treatment of a variety of immunodeficient diseases, as its broad spectrum anti microbial activity relieves the immune system of an enormous burden.
  • It should leave beneficial bacteria intact – This effect is most evident when GSE is used to treat Candida. Many proprietary Candida treatments affect not only the Candida, but also the intestinal flora which support recovery. Research has proven that GSE, taken in normal dosages, does not affect Bifidobacteria at all, and only insignificantly reduces Lactobacilli, despite its inhibiting effect on harmful intestinal bacteria. Thus creating the ideal environment to enable the body to restore its own balance.
  • Naturally derived – GSE is made by grinding the seeds, together with a portion of the flesh membrane. The process is natural, and the result is natural, needing, by its very nature, no artificial additives to assure its stability or longevity. The product is retailed in diluted form consisting of 33% GSE and 67% vegetable glycerine, and all references to it assume this combination.
  • Hypoallergenic – Most doctors could not establish any kind of allergic reaction in the use of GSE. However, about 3% to 5% of people are allergic to citrus fruit and could display an allergic reaction. Kinesiologists, however, know that not everyone who has a citrus allergy is allergic to grapefruit. I have tested this with a friend who has a documented allergy to citrus, who uses 15 drops a day to control the pain and immobility of osteoarthritis. She has built up her intake over a period of weeks with no harmful side effects, and a beneficial effect on her lifestyle.
  • Cost effective – The product is natural, requiring no expensive processing, no expensive additives, and no expensive storage or packaging conditions. It is used in drops rather than litres. Bottles retail at around £6, and my bottle lasts me, with daily use, for 4 to 6 weeks.
  • Backed up by solid scientific research – “The Healing Power of Grapefruit Seed” refers to 24 different pieces of research which were evaluated before the book was published, a body of international research across a broad spectrum of applications, and over 100 publications, varying from books on general sale to esoteric articles in specialist press publications. The spectrum is international and continuous, drawing on the experience of a growing number of holistic practitioners who use GSE therapeutically.  


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About Dorothy Cronin


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