• Weil Nutrition Corner
  • Meet Dr. Weil
  • Origins
  • Healthy Aging
  • Marketplace
  • Podcasts
  • Accessibility
  • Subscribe
Dr. Weil Logo Dr. Weil Logo Weil™ Andrew Weil, M.D.
  • Health & Wellness
    Health & Wellness
    Body, Mind & Spirit
    • Addiction
    • Allergy & Asthma
    • Autoimmune Disorders
    • Back Pain
    • Bone & Joint
    • Cancer
    • Colds & Flu
    • Dental & Oral
    • Diabetes
    • Disease & Disorders
    • Ears, Nose, & Throat
    • Feet
    • Gastrointestinal
    • Hair, Skin, & Nails
    • Headache
    • Heart
    • Insects & Parasites
    • Liver & Kidney
    • Mental Health
    • Pregnancy & Fertility
    • Respiratory
    • Sexual Health
    • Sleep Issues
    • Stress & Anxiety
    • Vision
    Balanced Living
    • Exercise & Fitness
    • Gardening
    • Healthy Home
    • Healthy Living
    • Meditation & Inspiration
    • Meet Dr. Weil
    • Pets & Pet Care
    • Technology
    • Wellness Therapies
    Health Centers
    • Aging Gracefully
    • Children
    • Condition Care Guide
    • Men
    • Women
  • Diet & Nutrition
    Diet & Nutrition
    Anti-Inflammatory Diet & Pyramid
    Cooking & Cookware
    Diets & Weight Loss
    Food Safety
    Nutrition
    Recipes
  • Vitamins, Supplements & Herbs
    Vitamins, Supplements & Herbs
    Herbs
    Supplements & Remedies
    Vitamins
  • Ask Dr. Weil
  • Blogs
    Blogs
    Bulletins
    Health Tips
    Spontaneous Happiness
  • Mushrooms
  • Sleep
Press "Enter" to search
Dr. Weil Logo Weil™ Andrew Weil, M.D.
  • Health & Wellness
    Health & Wellness
    Body, Mind & Spirit
    • Addiction
    • Allergy & Asthma
    • Autoimmune Disorders
    • Back Pain
    • Bone & Joint
    • Cancer
    • Colds & Flu
    • Dental & Oral
    • Diabetes
    • Disease & Disorders
    • Ears, Nose, & Throat
    • Feet
    • Gastrointestinal
    • Hair, Skin, & Nails
    • Headache
    • Heart
    • Insects & Parasites
    • Liver & Kidney
    • Mental Health
    • Pregnancy & Fertility
    • Respiratory
    • Sexual Health
    • Sleep Issues
    • Stress & Anxiety
    • Vision
    Balanced Living
    • Exercise & Fitness
    • Gardening
    • Healthy Home
    • Healthy Living
    • Meditation & Inspiration
    • Meet Dr. Weil
    • Pets & Pet Care
    • Technology
    • Wellness Therapies
    Health Centers
    • Aging Gracefully
    • Children
    • Condition Care Guide
    • Men
    • Women
  • Diet & Nutrition
    Diet & Nutrition
    Anti-Inflammatory Diet & Pyramid
    Cooking & Cookware
    Diets & Weight Loss
    Food Safety
    Nutrition
    Recipes
  • Vitamins, Supplements & Herbs
    Vitamins, Supplements & Herbs
    Herbs
    Supplements & Remedies
    Vitamins
  • Ask Dr. Weil
  • Blogs
    Blogs
    Bulletins
    Health Tips
    Spontaneous Happiness
  • Mushrooms
  • Sleep
  • Weil Nutrition Corner
  • Meet Dr. Weil
  • Origins
  • Healthy Aging
  • Marketplace
  • Podcasts
  • Accessibility
  1. Home
  2. Vitamins, Supplements & Herbs
  3. Supplements & Remedies

Is Grapefruit Seed Extract Any Good?

I’ve read about the anti-fungal properties of grapefruit seed extract, but I have also read about the potential presence of benzethonium chloride and other chemicals used in the manufacturing process. Is grapefruit seed extract safe?

Andrew Weil, M.D. | February 25, 2011

Grapefruit essential oil in a small bottle and fresh grapefruit, selective focus
1 min

Grapefruit seed extract (GSE) comes from the seed, pulp and white membranes of grapefruit. It has a reputation as an antifungal and antibacterial agent, but when I discussed your question with Tieraona Low Dog, M.D., an internationally recognized expert in the fields of integrative medicine, dietary supplements and women’s health, and an authority on botanical medicine, she said that it is unclear how potent GSE is as an antibacterial or antifungal. She said that many grapefruit seed extracts on the market are adulterated and noted that a German study of six commercial grapefruit seed extracts showed that five of these products contained benzethonium chloride, a synthetic antimicrobial often used in cosmetics and other topical preparations, as well as the preservatives triclosan and methylparaben.

Dr. Low Dog adds that this finding is consistent with those of other researchers who have found benzethonium chloride or triclosan in samples of liquid and powdered grapefruit seed extracts. When grapefruit seed extract is used topically (say, for treatment of athlete’s foot as I have recommended), the presence of these synthetic substances is not a big issue. But she cautions that grapefruit seed extract often is recommended for treatment of infant thrush (also a fungal infection) and says she would not recommended putting a potentially adulterated product in an infant’s mouth or that anyone use it internally.

It is probably safe to put a few drops of grapefruit seed extract in water in a spray bottle for an odorless way to kill household mold and mildew. As a treatment for athlete’s foot, you can try applying full strength grapefruit seed extract to the affected area two to three times a day. You can also use it as an alternative to tea tree oil to treat nail fungus. Paint it on affected nails twice a day for at least two months. But given the evidence of apparent widespread adulteration of grapefruit seed extract, I agree that it shouldn’t be taken internally.

Andrew Weil, M.D.

Dr. Weil on Healthy Aging

Start Your 14-Day Free Trial

Free Newsletters

Stay Connected With Dr. Weil

Anti-Inflammatory Diet

Follow Dr. Weil’s Food Pyramid

Get Dr Weils Newsletter Updates

Exclusive Lifestyle, Nutrition & Health Advice

Dr. Weil's FREE health living advice delivered to you!

By clicking "Subscribe," you agree to the DrWeil.com Terms and Conditions and Privacy Policy. You also agree to receive emails from DrWeil.com, and you may opt out of DrWeil.com subscriptions at any time.

Trending Now

bones calcium vitamin d
Supplements & Remedies

A Different Kind of Calcium?

Hands Of Woman Deformed From Rheumatoid Arthritis holding pills
Supplements & Remedies

A Supplement to Prevent Alzheimer's

iodine deficient non dairy milk
Supplements & Remedies

Am I Iodine Deficient?

Glass of light beer on the glass bar counter.
Supplements & Remedies

An Antioxidant In Beer?

Dr. Weil Logo Weil™ Andrew Weil, M.D.
Dr. Weil's Signature

Exclusive Lifestyle, Nutrition & Health Advice

  • About Us
  • Press Information
  • Advertising
  • Contact Us
  • Terms of Use
  • Privacy Policy
  • Accessibility

Terms of Use | Privacy Policy

Information on this website is provided for informational purposes only and is not intended as a substitute for the advice provided by your physician or other healthcare professional. You should not use the information on this website for diagnosing or treating a health problem or disease, or prescribing any medication or other treatment. Any third party offering or advertising on this website does not constitute an endorsement by Andrew Weil, M.D. or Healthy Lifestyle Brands.

© Copyright 2025 Healthy Lifestyle Brands, LLC. All rights reserved. Reproduction in whole or in part without permission is prohibited. www.drweil.com