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The Truth About Grapefruit Seed Extract

Since my original post on Grapefruit Seed Extract, I've stumbled upon some new eye-opening information, so I thought I'd expand the subject here.

The big controversy that's been going on for years with Grapefruit Seed Extract lies in its potential to be contaminated with benzalkonium chloride, parabens, and triclosan.  Numerous studies have tested samples of commercially produced GSE and found these contaminants to be present.  (See here, here, here and here.)  The biggest contaminant found is benzalkonium chloride, a chemical that rates a 7 in the cosmetics database that's a known immune system toxin, skin toxin, and possible cancer risk.

Some studies have shown that without these contaminants, a truly natural extract of grapefruit seed and pulp in ethanol or glycerin, had no antibacterial properties.  However, GSE apologists claim that GSE can be effective without these contaminants.  So, what is the truth? Is there such thing as a "pure" GSE, and if so, is it effective?

Grapefruit Seed Extract was first developed in 1972 by a man by the name of Dr. Jacob Harich.  Today, there is one main manufacturer of GSE that defenders claim is pure.  It is sold under the name Citricidal. This website describes how it is made:

  1. Grapefruit pulp and seed is dried and ground into a fine powder.
  2. The powder is dissolved in purified water and distilled to remove the fiber and pectin.
  3. The distilled slurry is spray dried at low temperatures forming a concentrated flavonoid powder.
  4. This concentrated powder is dissolved in vegetable glycerine and heated.
  5. Food grade ammonium chloride and ascorbic acid are added, and this mixture is heated under pressure. The amount of ammonium chloride remaining in finished Citricidal is 15-19%; the amount of ascorbic acid remaining is 2.5-3.0%.
  6. The ammoniated mixture undergoes catalytic conversion using natural catalysts, including hydrochloric acid and natural enzymes. There is no residue of hydrochloric acid after the reaction.
  7. The slurry is cooled, filtered, and treated with ultraviolet light.

As you can see, this isn't a truly natural process, it being treated with hydrochloric acid and ammonium chloride.  After all the chemical reactions occur, the final composition of the extract is made up of about 60% diphenol hydroxybenzene, a chemical classified as a quaternary ammonium chloride--the same as benzethonium chloride.  In fact, it is nearly chemically identical to benzethonium chloride. This is one possible reason that lab tests have shown GSE to be "contaminated" with benzethonium chloride--the equipment possibly misread the diphenol hydroxybenzene.

Typically, when a truly natural extract is made, plant matter is let to steep in a solvent such as water (as in making tea), in alcohol (like the vanilla extract you'd use in baking), or in glycerin (like with many herbal supplements you'd find at the health food stores) to extract the plant's beneficial or desirable compounds, whether it be a flavor, smell, or antioxidant.  It's a one or two step process that doesn't involve other chemical processing.  GSE is clearly not a natural extract, but a synthetic ingredient, considering it goes through 7 steps of processing and the extract doesn't retain the original compounds present in grapefruit.

Mountain Rose Herbs, one of the most respected and trusted suppliers of organic herbs, extracts, and essential oils lists the composition of the pure GSE they sell (which is most likely Citricidal brand):

Ascorbic Acid- 3%

Glycerol- 36%

Diphenol Hydroxybenzene (Quaternary compound from Grapefruit Bioflavinoid)- 58.5%

Heavy Metals- None detected

Benzethonium Chloride- None Detected

Methyl Hydroxybenzoate - None Detected

Propyl Hydroxybenzoate - None Detected

Triclosan- None Detected

So, while it is pure from other contaminants, it is primarily diphenol hydroxybenzene.  One fallacy I've found on discussion boards online have been that since it comes from Mountain Rose Herbs, it must be safe and organic.  You'll notice that this ingredient is not classified as certified organic on their website. 

When I first posted my Chemical of the Day on GSE, there were some comments written on the post.  I have to now revise my original replies with this new information in mind. 

Sally Leachko founder Meaodwlake Farm wrote:

I applaud your efforts Stepahnie. However, you are only exposing your readers to a fraction of the information available about GSE and controversy that surrounds this ingredient. Is some GSE contaminated? It appears so. Is all? Absolutely not. Meadowlake Farm Honeybee Products uses organic GSE from one source and we've had it tested by an independent lab multiple times. Contrary to what you indicate it has some anti-microbial properties, that is why we use it as a part of our proprietary 100% natural preservation system.

I originally commended her efforts to make sure that her extract was pure.  However, even though her extract isn't contaminated with other chemicals, knowing that "pure" GSE is composed of mainly diphenyl hydroxybenzene, I am forced to rescind my comments.  And while I'm sure that her motives are good (their company seems to work a lot towards sustainability and organic causes), I think that the industry is rife with misinformation, even from suppliers of chemicals to companies. 

Another reader of my original post wrote:

If the ingredient is listed as Extracts of Organic Grapefruit Seed (certified organic by Soil Association Certification Limited) in a product would it be okay?

I originally thought, sure, it's certified organic, it's fine.  However, now I have more information and have to change my reply.

Right now, Citricidal is actually made from organic grapefruit.  But, whether it's organic grapefruit or not, the extract is still going to contain diphenol hydroxybenzene.  But how did this company get a GSE that was certified organic, it being a synthetic chemical?  Well, notice that the certifying body isn't the USDA, by the Soil Association.  The Soil Association is the European organic standard, and the requirements are much less strict than that of the USDA.  They will allow and certify a synthetic chemical like GSE if it meets certain criteria for biodegradability, aquatic toxicity and bioaccumulation.  So, since the grapefruits were organically grown, and it meets the requirements, they approve the extract as organic, even though it's a synthetic chemical.  The Soil Association also approves phenoxyethanol as a preservative ingredient.  The USDA will not certify GSE, or allow it in a certified organic product.  If you see a USDA certified organic product with GSE, it is illegally labelled.  GSE is not on the USDA's list of approved non-organic substances (they allow a few non-organic ingredients like vitamin E in to their products).    

So, let's take a look at diphenol hydroxybenzone.  Why exactly do we want to avoid it?

The makers of GSE states that it's been extensively tested for toxicity and health effects and claim that it is safe.  However, all of these studies only tested the effects when it was taken internally.  When taken internally, chemicals have a chance to be metabolized and broken down by the body.  However, when applied topically, they can be absorbed in the skin and enter the bloodstream in their whole form.

The problem that I see with diphenol hydroxybenzene is the fact that on a molecular level, it's full of benzene rings.  The name "diphenol" means that there are two phenol groups.  Phenol is a benzene ring with one hydrogen and one oxygen molecule.  Chemicals with benzene rings are particularly worrisome in personal care products because once they enter the bloodstream they can mimic the hormone estrogen.  [For a detailed explanation of this, check out my article on Japanese Honeysuckle Extract.]  Estrogen is primarily made up of benzene rings, and our estrogen receptors are made to "fit" benzene rings.  So, when a chemical with a benzene ring enters the body, it has the potential to lock up in the estrogen receptor and can stimulate it. Estrogen mimickers also have the potential to raise levels of estrogen by inhibiting the function of an enzyme called SULT1E1, that helps to remove estrogen from the body. [For more on this, read my article here, scrolling down to "where my discussion begins."]

The strange thing with diphenol hydroxybenzene is that there are no chemical diagrams provided by the manufacturer (or anywhere, even in organic chemistry guides), and the name of the chemical doesn't help (as it should) in finding its chemical structure.  Hydroxybenzene is just another name for phenol, so the name means "2 phenol phenol," which is weird.  My guess is that it's a simplified name for the chemical.  The manufacturer does say that hydroxybenzene is nearly identical to bezenthonium chloride, which looks like this:

The two hexagonal rings you see in the structure are the problematic benzene rings that I was talking about.  And indeed, this chemical has been shown to be an endocrine/reproductive disruptor by a 1995 RTEC study.  It also carries the risk of being a strong skin irritant, and it showed tumor formation at moderate doses.  (see the Cosmetics Database report) However, in its defense, according to National Toxicology Program studies, it exhibited no evidence of carcinogenity or endocrine disruption in a two-year rat and mouse study.  This study did, however, show that the animals treated with benzethonium chloride did have increased inflammation in the body and a slightly lower survival rate than the control group.

The bottom line is that while there is conflicting evidence of the other negative health effects of benzethonium chloride (and the diphenol hydroxybenzene present in GSE), at the very least it's a skin irritant that increases inflammation in the body.  My personal opinion on it is that it is safer than other preservatives. However, if you prescribe to an organic mindset and lifestyle, you will want to avoid Grapefruit Seed Extract, for it is nothing other than a synthetic chemical.

Note: Grapefruit essential oil is natural, and not the same thing as Grapefruit Seed Extract.

References (3)

References allow you to track sources for this article, as well as articles that were written in response to this article.

Reader Comments (76)

Hi Stephaine,

First I love your website and love that you do a blog to help inform about chemicals.. yo are a rare find in today's world...thank you for all that you is appreciated! I am writing to ask your opinion on something....i have to be careful with anything that is estrogenic since my dad and I grow wheatgrass to cure my mom who has breast cancer....we are spraying it with GSE since we were told that kills the mold that regularly grows on it...! I feel a bit you have any suggestions on what we could replace the GSE with to kill the mold? Thanks for any direction you can lead us in. Have a beautiful day Stephaine.

Thu, August 7, 2014 | Unregistered CommenterCrystal

Hi Stephanie,

I was about to make an order of a GSE product after having been recommended it to help naturally get rid of a pinworm infestation that I have had for about 8 weeks now. The biggest problem being that I am nearly 5 months pregnant. Having read your article I am reluctant to overcome them with GSE. Would you recommend any other way of naturally getting rid of them?

Sun, August 10, 2014 | Unregistered CommenterLucy

Eek! Unfortunately I can't give medical advice and don't have a suggestion for you, as I don't have experience with pinworm. Perhaps visiting with an Osteopath, Functional MD, or Naturopath will give you some suggestions.

Tue, August 12, 2014 | Registered Commenter[Stephanie Greenwood]

I used this stuff with my kid who has severe asthma that behaves live CF. He catches a cold and within 24 hours on machine, 48 steroids needed for support to just cough mucus up. 2 drops to 16 oz of water over 3 days changes that tide now. I get this stuff off the shelf locally. While this is informative--figure out what works for you. Big Pharma will study naturals to death but somehow misses all the damage caused by their meds which is what got my family here in the first place. Overdosing antibiotics in NICU for five months. We have suffered 14 years as a result. This is the only thing that broke the cycle. Pneumonias every 10 weeks like clock work in the beginning. Leaky bowels from meds. Allergies like crazy (121) Now there are 4 that are notable that remain--2 epipen level. Does it work? I would not have cabinet without it. Wish I had it when my dad passed from H1N1 maybe things would have been different for him. Use your own judgment.

Fri, October 10, 2014 | Unregistered CommenterSoCalMomof2

Been on a quest to live after 20 yr old root canals poisoned my system and colonoscopy was last straw assault on my immune system.... Here are some of my "discoveries": activated charcoal (why not physically remove toxins?), Bentonite clay too. ASEA( not an easy purchase when you can't work, d-ribose(energy), black strap molasses (energy), Chia seed, hydrate and drink (energy), unrefined coconut oil (claim it's anti-vial,microbal,fungal), food grade hydrogen peroxide...take 35% h202 (1oz) add to glass bottle, add 11 oz distilled water only. You now have 3% food grade hydrogen peroxide (H2O2) May be used adrop at a time in distilled water on an empty stomach 2 hrs before or 1hr after meals. I have worked up to 11 drops.

Sat, November 1, 2014 | Unregistered CommenterReba

Lugol's iodine. (Some people are allergic to this(those who are allergic to shellfish) so BE CAREFUL. This was used for de cades as a anti-microbial until big pharma took over...(See Dr. Hulda Clark's work. Magnesium chloride has also cured big challenges...look into l-glutamine(for alimentary healing and post surgery and anti catabolic for cancer. Beta glucan, turmeric, bromelain,pancreatin, garlic, oil of oregano for cancer, sambucas(black elderberry and lysine(ant-i virals), baking soda and molases for utii's, high dose vitamin c:1tsp. Ascorbic acid in 1oz water, 1/2 tsp baking soda , let fizz. Add drink of choice and drink....apply dmso about 10 minutes later to increase absorption (see cancer , zapper from Canada, cayenne pepper reportedly immediatelystops a heart attack. N-A-C(cysteine) is used in er's for poisoning

Sat, November 1, 2014 | Unregistered CommenterReba

Hi -- thank you so much for providing compelling information into GSE. I just want to piggyback on a comment/question posted by Sophie in 2013 -- on the use of GSE as a laundry disinfectant. My toddler daughter has a stubborn case of impetigo that was effectively treated by oral antibiotics at the end of summer but might've been reintroduced by diaper covers (that can't be washed with hot water or bleach). Meanwhile, we switched to disposable diapers, which has helped clear the rash on my daughter's bottom, but her impetigo has since spread to her face. Going on a recommendation made by a local diaper store owner, I purchased a bottle of GSE (in glycerin) to put (20 drops) in the last rinse cycle of the laundry (sheets, diaper covers, everything!). I haven't really used it yet, so I'm wondering what I should expect if I do. Is it safe to use in laundry? Should I worry about absorption by the skin? Is it really an effective disinfectant? Thank you! -caroline

Mon, November 17, 2014 | Unregistered Commentercaroline

Thanks for your question, Caroline. GSE can be an effective disenfectant, and, when used in laudry as you've described, wouldn't pose a risk, as it would be diluted and washed out of the fabric.

Mon, November 17, 2014 | Registered Commenter[Stephanie Greenwood]

Thank you for the info. What would you suggest to take instead? Maybe just eat grapefruit with the seeds included? Or maybe just a simple grapefruit (fruit and seed) powder? What brand would you recommend? Thanks!

Fri, January 9, 2015 | Unregistered CommenterAngelic

@Angelic--thanks for your question! What to take instead? Well, that's a complicated question--what are you trying to achieve?

Fri, January 9, 2015 | Registered Commenter[Stephanie Greenwood]

Here's my first-hand experience with GSE: it cleared up an athlete's foot fungus infection that had persisted for over two years despite the use of external over-the-counter, prescribed, and natural remedies. I've never found it to be particularly effective as a gargle and I've avoided out-and-out drinking it because of safety concerns. But I'll probably keep a bottle around for use as a disinfectant and for occasional external use.

Wed, April 8, 2015 | Unregistered CommenterSylvia

I was starting to use GSE from NutriBiotic for my toenail fungus which I have for 20 years now, hoping this would be the answer. But, now I am wondering because of it being absorbed through the nail rather than internally, if it is the best route to take. Do you have any suggestions?

Fri, April 24, 2015 | Unregistered CommenterJeannette Lerma

@Jeannette--It's very difficult for me to say what's right for your situation; a fungal infection is a medical condition; the benefits and risks of any medicine you take should be discussed with a qualified healthcare professional.

Tue, May 12, 2015 | Registered Commenter[Stephanie Greenwood]

this is such an useful post, grapeseed oil has been praised by so many dieticians nowadays, we need to know the truth, and that is what this post has done, thanks!

Tue, June 2, 2015 | Unregistered CommenterMelissa @Essential Oils

Hi I notice 100% pure use different kinds of grape fruit?Citrus Grandis (Grapefruit) Seed, organic grapefruit seed and Vitis Vinifera (Cabernet Grape) Fruit. Are these all grapefruit seed extract? Or is grapefruit seed extract just called grapefruit seed extract/ citrus paradisi. Thank you.

Sun, June 14, 2015 | Unregistered CommenterEmma

Can you please tell me what is a safe Natural Preservative that would take the place of Grapefruit Seed Extract? I have been researching so I can make my own perfumes, etc... And this is all so confusing.

Fri, September 18, 2015 | Unregistered CommenterTracy

GSE is recommended as a part of the complete treatment of Lyme Disease (GSE for cystic form to avoid dangerous Flagyl, Tindamax or Plaqueril; patient is 6 yrs old). I would appreciate any information on what to take instead or if in this regard it would be clinically appropriate.
Thank you

Thu, October 15, 2015 | Unregistered CommenterRebecca W

thank you for shedding light on this matter!

Mon, January 11, 2016 | Unregistered Commenternuur

What about using Biokleen All Purpose Cleaner? It has GSE

Thu, July 21, 2016 | Unregistered CommenterJoel

I hace been drinking gse also known as DF100 for 30 years in extremely high doses. I have also used it topically and in biogenic air purification. I have found that GSE kills all fungus known to mankind. I have also found in air purification that it is 99% affective in killing bacterial airborn toxins. I've used petree dishes to grow live cultures in the air. The before and after affects were truly amazing, as almost all the airborn bacteria were dead. I would highly recommend this product to anyone.

Mon, September 19, 2016 | Unregistered CommenterGary Clifford

Great info as always!

So is it possible to use grapefruit seed tincture made only with an organic 190 proof alcohol extract and get the same antibacterial benefits? (And if so would this effect all bacteria, including beneficial?)

For many years I used grapefruit seed extract in my "sponge water" -- where I soaked my dishwashing sponges in an open jar of water with added tea tree oil, peppermint oil and a squirt of GSE during the night to inhibit bacterial growth and extend the life of the sponges. It doesn't work as well without the GSE. But it is concerning using GSE since the palms of the hands are absorbent and one must exercise caution in what we are putting on our hands no matter how seemingly small, these things can build up.

Mon, January 2, 2017 | Unregistered CommenterLeslie Estes

@Leslie, thanks for your question!

No, a grapefruit tincture is not going to work the same as a commercially-prepared GSE. The synthetic chemicals that the grapefruit compounds are being turned in to through the processing are what give it its disinfecting properties.

Unless, of course, the grapefruit tincture was at 15% or more of your overall formula--at which point the alcohol would be your preservative. :)

Sat, January 7, 2017 | Registered Commenter[Stephanie Greenwood]

Fascinating, although I am coming very late to this. However, just wanted to say that GSE has saved me and others on many occasions during many years living in India and I now never travel without it, especially to countries with poor sanitation. So, in weighing up this new information, I would say that for me it has been a choice between harsh doses of antibiotics, i.e. the atomic option for the gut, or gse. Indeed, some parasites that I have dealt with are known for antibiotic resistance, such blastos cystos, but GSE deals with them quite well, or at least quietens them down for a while. It is slightly perturbing to find out that they are in fact not part of naturopathy, but on second thought, it nonetheless remains a choice of a lesser of two evils. Indeed, I was impressed a few years ago how effectively gse dealt with a bad case of throat thrush, caused by antibiotics in the first place, instead of the horrific medicine the doctor prescribed. That being said, your information will reinforce my search for more naturopathic remedies for more long term chronic use, e.g.oregano oil, various tinctures, etc. Thanks!

Fri, July 21, 2017 | Unregistered CommenterAndrew

Hi, I know this post is old but I wanted to offer my anecdotal experience with GSE on relation to it's effects on estrogen. I use GSE mixed into saline nasal spray any time I feel a sinus infection coming on and it knocks it right out before it can take hold. I can tell you from personal experience however, it does affect the hormone levels so I agree about it mimicking/increasing estrogen. Each time I use it, regardless of where I'm at in my cycle, it is guaranteed to bring on my menses within a day or two, so for that reason, I do not like to use it but it still beats a sinus infection. I'm honestly surprised I've not heard this side effect from others because it is a very consistent side effect for me. I use the Citricidal GSE btw.

Mon, February 5, 2018 | Unregistered CommenterLiss


After a rough year including norovirus, the harsh chemical cleaners and fumes give me migraines, but I've had to use them. I was so hopeful about using Citrocide Nutribiotics GSE diluted in water with tea tree oil to replace these harsh cleaners. I have hormonal imbalance, and now I'm unsure if I use it as a disinfectant cleaner and toy sanitizer if it will affect my hormones and the children. I am a germaphobe and need a safe disinfectant. Just looking for a safe disinfectant has caused much stress and indecision. Help? Please? Thank you!

Tue, February 20, 2018 | Unregistered CommenterAlice

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