the evil, vile, repugnant grapefruit seed extract (GSE)

There are certain topics that make me rant, pretty much every time they come up... one of these is GSE - grapefruit seed extract. It's sold as a "natural antimicrobial/preservative" but in truth is adulterated with horrible, awful, dreadful, deplorable, revulsive chemicals that are carcinogens, endocrine disrupters, allergy sensitizers, and environmental pollutants.

GSE is not safe to ingest, it's not safe to put on your skin, and it's not even safe to use in any manner where it will be released into the environment. Please don't use it for parasites, don't use it as an ingredient in "natural detergents" (Bio-Kleen uses GSE), in soaps and by no means expose your infants to it to "fight thrush". Most GSE is more heavily laden with chemicals than Lysol (thanks to Todd Caldecott for that tidbit).

(please, before you write me looking for an exception, do at least read all of the excerpted quotes (and ideally the longer articles), as well as my reply to the most common "yeah, but..." response I get, located below the quotes...)

The Adulteration of Commercial “Grapefruit Seed Extract” with Synthetic Antimicrobial and Disinfectant Compoundsby (john cardellina)

"Tests conducted in multiple laboratories over almost 20 years indicated that all commercial GFSE preparations that exhibited antimicrobial activity contained one or more synthetic microbicides/disinfectants, while freshly-prepared extracts of grapefruit seeds made with a variety of extraction solvents neither exhibited antimicrobial activity nor contained the antimicrobial synthetic compounds found in the commercial ingredient materials. Furthermore, over the course of the 18 years covered by the various analyses, the actual antimicrobial compounds found in the putative grapefruit seed extracts changed from triclosan and methyl p-hydroxybenzoate in early samples to benzethonium chloride in the middle years to mixtures of benzalkonium and/or alkonium chlorides in more recent years. The suggestion on a commercial website (Citricidal) that these antimicrobial compounds are formed from the phenolic compounds naturally occurring in grapefruit seed and pulp by heating them with water, ammonium chloride, and hydrochloric acid is not supported by chemical evidence, or any known organic chemistry pathway."

Adulteration of Grapefruit Seed Extract Citrus paradisi (john cardellina)

"Manufacturers have claimed that a proprietary extraction process, involving treatment/reactions with ascorbic and hydrochloric acids and ammonium chloride, produces compounds similar to the known antimicrobial quaternary amine compound benzalkonium chloride,³ although no rational organic chemistry mechanism has been provided for this non-credible purported transformation. Further, the compounds in question are not just similar to benzalkonium chloride or benzethonium chloride; researchers have isolated the compounds in question from commercial products and, using authentic reference standards, have shown them by high-performance liquid chromatography (HPLC) retention times and ultraviolet, nuclear magnetic resonance (NMR), and mass spectra to be identical to those authentic reference materials... A series of 13 publications over 25 years comprises the evidence for adulteration of GFSE. A variety of analytical methods were utilized in studies emanating from Japan, European countries, and the United States. The results show a consistent pattern of adulteration; moreover, the results also show that after the first two of the aforementioned publications appeared, the synthetic microbicides present began to shift."

GSE Overview (todd caldecott)
"While on the one hand the marketing of GSE could be nothing more than a kind of charlatanism, there are additional concerns about the long term safety of ingesting the aforementioned preservatives. I am quite sure that many of the people currently using GSE, who espouse the value of natural alternatives over commonly used synthetic drugs and spend their hard earned money to buy “all-natural” products, would be shocked to learn the mechanism of GSE’s biological activity."

Grapefruit Seed Extract Explained (kathy abascal)

"The main active components in the finished product are a group of quarternary ammonium chlorides including benzethonium chloride that make up 8-17% of the product. Benzethonium chloride is not a substance that occurs naturally in grapefruit seeds. It is a manufactured chemical that is lacking in safety data but may be an endocrine and skin toxicant. Endocrine toxicants are chemicals that have the ability to disrupt our hormones. Commonly encountered endocrine toxicants include PCBs and DDT. “Not to worry,” assures the manufacturer of Citricidal: “Benzethonium chloride is a well-known synthetic antiseptic agent; it is not added to the grapefruit extract, but if formed from the orginal grapefruit flavonoids during the ammoniation process.” Using grapefruit seed extract is about the same as going to a pharmacy and buying triclosan or any other synthetic antimicrobial chemical. They may work. They may be safe. Or they may not be safe."

Grapefruit Seed Extract. Natural or synthetic? (rob mccaleb)
"The presence of preservatives, harmful to human health, has been reported [in] cosmetic and medicinal GSE products.” We created a method “to quantify all GSE-relevant preservatives in one analytical run by a fully validated assay” and found preservatives “commonly used (as) synthetic antimicrobial agents whose formation in the plant or during the extraction process is very unlikely."

Simultaneous identification and quantification by liquid chromatography of benzethonium chloride, methyl paraben and triclosan in commercial products labeled as grapefruit seed extract (Avula B, Dentali S, Khan IA)
"A HPLC method has been developed which permits the quantification of methyl paraben, benzethonium chloride and triclosan in various samples of grapefruit seed extract (GSE). The best results were obtained with a Phenomenex Gemini C18 column using gradient mobile phase of water (0.1% acetic acid) and acetonitrile (0.1% acetic acid) with a flow rate of 1.0 mL per minute. The detection wavelength was 254 nm for methyl paraben, and 275 nm for benzethonium chloride and triclosan. The main synthetic antimicrobial agent identified in commercial GSE samples was benzethonium chloride in concentrations from 0.29-21.84%. Positive ion electrospray MS of a commercial GSE sample showed a molecular ion at m/z 412 [M+], which matched that of a standard of benzethonium chloride. Triclosan was detected in two samples at 0.009 and 1.13% concentrations; while methyl paraben was not detected in the samples analyzed"

Several more scientific references on adulteration...
http://www.yesyesyes.org/GSE.htm ...yes, I know that's a sex lube site, but no, I have no idea whether it's good or not. I encourage you experiment to your hearts delight (and with your hearts delight)

(hi! it's jim again...)

If you've read through the links & quotes, you'll see that the companies selling adulterated Grapefruit Seed Extract have shifted which chemicals they've added, though those chemicals are often "quaternary ammonium compounds", and these are really freakin' bad (though, to be fair, this is an in vitro study):

Common Antiseptic Ingredients De-Energize Cells and Impair Hormone Response (trina wood)

"A new in-vitro study by University of California, Davis, researchers indicates that quaternary ammonium compounds, or “quats,” used as antimicrobial agents in common household products inhibit mitochondria, the powerhouses of the cell, as well as estrogenic functions in cells. Their findings appear online today (Aug. 22, 2017) in Environmental Health Perspectives, a publication of the National Institute of Environmental Health Sciences... This paper adds to the growing number of studies which find that quats may not be as safe as previously believed,” said Terry Hrubec, associate professor at Edward Via College of Osteopathic Medicine-Virginia, and not a co-author on this study. “The fact that six out of the 10 most potent mitochondrial inhibitors were quats shows that this class of chemicals likely affects living systems. The results from this study are concerning because almost everyone is exposed to quats on a regular basis.”

I've had this page up for years and years and years, but I still get lots of email, and most of it is from people wanting to think there's some way they can still use GSE. This usually revolves around one issue: "All these quotes are about adulterated GSE, so this issue doesn't really apply to GSE that isn't adulterated..."

However, if you read the info quoted and linked to above you'll see that, yes, there are some GSEs that don't contain chemical adulterants, but none of the non-adulterated GSE products that have been tested have shown any significant activity as a preservative or antimicrobial.

So, yes, there are non-adulterated GSEs, but they don't actually work for the stuff people use GSE for. We can look at this another way and conclude that if your GSE does work as a preservative/antimicrobial, it's probably because it has adulterant chemicals in it.

To be fair, Citricidal insists that it's product doesn't have any adulterants in it, and they'll give you a certificate of analysis stating that there's <5.0 ppm Benzethonium Chloride, Benzekonium Chloride, Triclosan or Methyl 4-Hydroxybenzoate in their GSE. It looks like this:

While this seems promising (maybe even an out?), I feel this information should be looked at with critical eyes:

• If no GSE that hasn't been adulterated with chemicals has been shown to be effective as an antimicrobial, then how in the world is Citricidal working?

• John Cardellina (quoted above) writes, "over the course of the 18 years covered by the various analyses, the actual antimicrobial compounds found in the putative grapefruit seed extracts changed from triclosan and methyl p-hydroxybenzoate in early samples to benzethonium chloride in the middle years to mixtures of benzalkonium and/or alkonium chlorides in more recent years."

What this appears to suggest is that as adulterants were discovered and tested for, new adulterants began to replace them. So, Triclosan was found to be an adulterant in GSE, so people started testing for Triclosan. And, tests came back negative. But then people started to find Benzethonium Chloride in GSE (which wasn't there before...). So, if you get a certificate stating that your GSE has no Benzethonium Chloride, Benzekonium Chloride, Triclosan or Methyl 4-Hydroxybenzoate in it, that doesn't mean that there isn't some new adulterant being added, because exactly that has happened before. I mean, it's not like the companies that make GSE ever listed adulterants on their labels or said "oh, yeah, we add that..." in the past.

• Citricidal maintains that (and I'm quoting their page here) "Citricidal® is synthesized from the polyphenolic compounds found in grapefruit seed and pulp. Numerous reactions are involved, including distillation, catalytic conversion, and ammoniation. The active component of Citricidal is a quaternary ammonium chloride (a diphenol hydroxybenzene reacted with ammonium chloride) similiar to benzethonium chloride when analysed in accordance with USP XXII/NF XVII.".

So what it appears that they're saying here is that the similarity of the "quaternary ammonium chloride" that is the active ingredient in Citridical is being misidentified with Benzethonium Chloride in tests.

BUT... again, John Cardellina has specifically addressed this assertion, stating that "The suggestion on a commercial website (Citricidal's) that these antimicrobial compounds are formed from the phenolic compounds naturally occurring in grapefruit seed and pulp by heating them with water, ammonium chloride, and hydrochloric acid is not supported by chemical evidence, or any known organic chemistry pathway."

Really, the only evidence I ever see of adulterant-free GSE (that actually works) is on websites that sell it, sharing reports like the one above that came from the manufacturer.

And sure, just because the manufacturer says something doesn't mean we should assume it's wrong and that they're lying. But when the manufacturer says something that appears to be refuted by every other source of information, and makes claims "not supported by chemical evidence, or any known organic chemistry pathway", we should be pretty skeptical about it.