Grapefruit Seed Extract

Grapefruit Seed Extract: Overview

Grapefruit seed extract (GSE) is truly a broad-spectrum natural antibiotic, capable of killing a wide variety of pathogens.  Highly active against protozoa, bacteria, yeast and some viruses, it has been used for quite some time in the treatment of parasitic infections.  It is nontoxic, generally hypoallergenic and can be administered for up to several months, which may be required to eliminate stubborn infections.

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The extract of the inner rind and seeds of grapefruits (Citrus racemosa) is becoming known as one the best topical and internal antiseptics one can find.  Popularized by the trade name Citricidal, grapefruit seed extract is bacteriostatic as well as bactericidal at various concentrations.  It is active against a wide variety of bacteria and fungi.  It has also been shown to be very effective against parasitic organisms such as giardia.


GSE is sold both as "Grapefruit Seed Extract" and "Citrus Seed Extract".  Unless otherwise indicated on the label, these products are usually made from grapefruit seeds only.

Grapefruit seed extract is often found diluted in sprays to disinfect surfaces used in food preparations.  The dry extract powder is found in antibacterial, anti-fungal, and anti-parasitic formulations.

Why it is Recommended

Grapefruit seed extract preparations can be used both internally and externally.

  • External Use: GSE can be used externally as a disinfectant for both intact skin and to prevent infection in wounds.  A study in Brazil found it to be 100% effective (at 100ppm) for skin disinfection when used as a pre-surgical prep compared to an effectiveness rate of 72% for alcohol and 98% for commercially available surgical soap.
  • Internal Use: GSE can also be used internally to treat chronic infections.  It is often recommended at a rate of 3 times per day.  Dosage should not exceed a total of 1500mg per day.
  • Nasal spray: Spray or use an eye-dropper to get several diluted drops into each nostril, and then swing the head quickly forward and down (so head is upside-down), forcing the liquid up into the nasal passages.  Use up to six times per day.
  • Douche: GSE is added to one pint of water.  Use twice a day as a douche for up to a week, in the treatment of yeast infections.

Grapefruit seed extract has been shown to be effective in treating hundreds of different organisms including: Shigella, Staphylococcus, Pseudomonas aeruginosa, Giardia lamblia, Diplococcus pneumoniae, Haemophilus influenzae, Mycobacterium species, Campylobacter, Candida albicans, Escherichia coli, Streptococcus, Salmonella, Klebsiella, Proteus, Cholera, Chlamydia trachomatis, Trichomonas vaginalis, Legionella pneumoniae, Helicobacter pylori, Herpes simplex 1, Influenza A2, and measles virus.  GSE has been shown to kill both gram-negative and gram-positive strains of bacteria.


Different products may vary in strength so you should follow the label or your doctor's directions for any particular product.  As concentrated solutions, they almost always require dilution, and a different dilution for different forms of application.  Its bitter taste may be avoided by mixing it with carrot, vegetable, orange or grapefruit juice, or by taking it in capsule form usually just after a meal.

Counter-Indicators and Warnings

In much the same way that synthetic antibiotics can kill off the naturally occurring flora which exists in one's body, so might Grapefruit seed extract.  Consequently, if this herb is to be used long-term in the treatment of a chronic infection, supplemental acidophilus may need to be taken.  However, while one study found that GSE significantly inhibited E. coli, another normal inhabitant of the GI tract, it left the important and beneficial Bifidobacteria unchanged, and only slightly reduced the Lactobacilli species.

People using GSE should be aware that they may have, or may develop an allergy to this preparation.  Persons with a known citrus allergy are at higher risk.  Should you develop a rash or experience any other symptoms while using it, discontinue use immediately.

On This Page

Grapefruit Seed Extract:

Grapefruit Seed Extract can help with the following:


Bacterial Dysbiosis

Citrus seed extract may be a desirable first line of treatment because of its broad spectrum of antibacterial, antifungal and antiprotozoan benefits.  The usual dose required is 600-1600mg per day.  Animal studies have shown no toxicity except for intestinal irritation producing diarrhea at very high doses.  The mechanism of action is not known; there is no evidence of systemic absorption.


Vaginitis/Vaginal Infection

Citrus seed extract is useful for vaginal candida infections.  In a study done by the Universidad Autonoma de Nuevo Leon in Mexico, 20 women douched using grapefruit seed extract every 12 hours for 3 consecutive days.  15 patients were cured after the first treatment.  Four patients received treatment twice to become symptom free and receive negative laboratory results and 1 patient repeated the treatment 3 times until the lab report came back negative.


Yeast / Candida Infection

Chronic candidiasis can be successfully treated with grapefruit seed extract according to the many clinics and medical practitioners now prescribing it.  Dr Leo Galland, who prescribes it for chronic candidiasis, has reported treatment failure in fewer than 1% of cases, and considers it to be "a major therapeutic breakthrough for patients with chronic parasitic and yeast infections."

Athletes Foot

This extract is a powerful all-around antimicrobial product and is an excellent disinfectant.  Make a solution of 100 drops in two ounces of water and apply to the affected areas with a cotton ball two or three times a day.



Grapefruit-seed extract can be taken internally or used as a gargle.


Entamoeba Infection

In a series of almost 200 patients treated for giardia or entamoeba histolytica by a Dr. Parish and his associates over a two month period, grapefruit seed extract gave symptomatic relief more than any other treatment that was tried.

Giardiasis Infection

In a series of almost 200 patients treated for giardia or entamoeba histolytica by a Dr. Parish and his associates over a two month period, grapefruit seed extract gave symptomatic relief more than any other treatment that was tried.



When dysbiosis is present, treatment with antibiotics or with a natural antibiotic derived from grapefruit seeds has produced major improvement in the GI symptoms of eczema patients and moderate improvement in the severity of eczema.  One advantage in the use of grapefruit seed extract over conventional antibiotics lies in its antifungal activity.  This agent adds a second therapeutic dimension and eliminates the possibility of secondary candidosis.  The minimum effective dose of grapefruit seed extract for bacterial dysbiosis is 600mg per day.


Grapefruit or citrus seed extract has been reported to help.

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