A little over 25 years ago a paper got published in the journal Science showing that BHT, a common food preservative, could inactivate herpes simplex and other lipid-coated viruses in lab dishes ¹. Two years later another paper in the same journal reported similar results, but this time in live animals-dietary BHT could prevent chickens from dying of Newcastle disease ². Like herpes simplex, NDV (the virus that causes Newcastle disease) is lipid-enveloped, i.e., its nucleic acid core is sheathed in a fatty membrane. Viruses of this type require an intact membrane to be infective. BHT seems to work against such viruses by disrupting (“fluidizing”) their viral membranes.

In the chicken study cited above, the amount of BHT needed to inhibit NDV turned out to be equal to the amount already present in chicken feed as an additive, i.e., 100 to 200 parts per million of total diet ². Assuming a comparable result for humans and a total food intake of about 2 kilograms per day, this would mean that 200 to 400 milligrams of BHT ingested daily should be adequate to protect many people from infection by herpes and other lipid-coated viruses. See Table below for a listing of common viruses which have a lipid envelope and are therefore amenable to inhibition by BHT.

If our diet consisted exclusively of foods containing BHT as a preservative (such as some breakfast cereals, potato flakes, chewing gum, and certain baked goods made with shortening), we’d probably get enough BHT to ward off herpes-or mumps and measles for that matter. But we don’t. Most of our diets tend to be more varied than that and, besides, in recent years we’ve all been conditioned to avoid food additives.

The other option for getting enough dietary BHT is to consume it as a food supplement, a controversial proposition at best because it isn’t a nutrient—it’s a synthetic antioxidant. Nevertheless, this is precisely what some pioneering life-extensionists did in the late ’70s. Inspired by early scientific reports on the antiviral activity of BHT, a number of people suffering from herpes began to experiment on themselves. As described in several books published a few years later, the BHT experimenters discovered that a daily dose of 250 to 1000 mg resulted in rapid recovery from herpes eruptions with no recurrences ^3, 4. This figure is in good agreement with the estimate based on the chicken study above.

In addition to these anecdotal reports, a number of studies published over the years have confirmed the activity of BHT against many different human and animal viruses, including such members of the herpes family as CMV or cytomegalovirus ⁵ and pseudorabies ⁶ as well as genital herpes ⁷. BHT has been shown to inhibit infectivity of HIV ⁸, the AIDS virus, although contradictory results have also been reported ⁹. Several studies have revealed a protective effect of BHT against the development of influenza infection as well ^10, 11. The mechanism involved may have to do with the fact that BHT is a highly potent, membrane-active antioxidant as well as a membrane fluidizer. It’s known that reactive oxygen species (ROS) play a role in the pathogenesis of viral infections-including RNA viruses such as influenza, DNA viruses such as hepatitis B, and retroviruses such as HIV-and it’s been suggested that antioxidants may be useful as therapeutic agents in such infections ¹². This dual antioxidant/antiviral behavior of BHT means that BHT can inhibit some viruses at different stages of infection-at the initiation phase, where BHT can prevent an infection from getting started in the first place, and in the acute phase, where BHT can suppress an ongoing infection.

If BHT is so effective against lipid-enveloped viruses, why don’t doctors prescribe it for their patients? The answer is that almost none of the controlled studies on the antiviral properties of BHT have been performed on humans; most of the experiments thus far have been conducted in lab dishes (in vitro) or in animals. A human clinical trial of BHT cannot be performed because the Food and Drug Administration (FDA) has approved BHT for use only as a food preservative, not as a medicine ⁴. But that hasn’t stopped some people from using BHT on their own to treat herpes or other viral conditions.

In the past, safety concerns have been sometimes raised about BHT because of its reputed toxicity when given to rats in massive doses-doses much larger than those usually consumed for their antiviral effect. (For additional information on safety issues, see Questions & Answers About BHT Safety.) On the other hand, 25 years is long enough for any adverse effects as well as positive benefits to have shown up in humans. Many individuals-including my friend Roger, whom I’ve known since high school-have been supplementing with BHT on a regular basis for years at a time. Roger looks pretty healthy to me these days, but I phoned him anyway to press him for details on his BHT experience.

Roger first began taking BHT in 1984 after reading about it in Pearson and Shaw’s groundbreaking book ³. Initially he took about 1 gram per day because he was buying BHT in bulk at the time and larger amounts were easier to measure out than smaller ones. Later he was able to obtain BHT in capsules containing 250 mg per cap, and from that point on he took 250 mg every day for 6 to 7 years. Not surprisingly, during this period he remained completely free of herpes eruptions. More surprising is that he still remains herpes-free to this day, 10 years after his last dose of BHT. Around 3 years ago Roger had a comprehensive physical exam, including blood work. His physician told him that no antibodies to the herpes simplex virus could be found in his system.

Today Roger’s health is generally excellent, with no indication that his years of supplementing with BHT have harmed him in any way. The only adverse effect he ever encountered happened early on, while he was still experimenting with the size of the dose. Roger found that taking 3 grams of BHT each day resulted in dizziness and disorientation, which quickly disappeared when he cut his dose back to 1 gram per day. No adverse effects were seen thereafter.

Of course, a sample of one doesn’t constitute much of a survey. I needed to consult a larger database, so I turned to Steven Fowkes, resident guru at the Cognitive Enhancement Research Institute (CERI) in Menlo Park, California and co-author of Wipe Out Herpes with BHT ⁴. Steve, by the way, is working on an updated version of his 1983 book; he’s also the editor of Smart Life News, the CERI newsletter, which offers a wealth of useful information on BHT and other products. For information on CERI and its newsletter, go to http://www.ceri.com/ on the web or call (650) 321-2374.

Steve Fowkes was unequivocal in his judgment. In the decades since BHT first arrived on the supplement scene, Steve hasn’t heard of any adverse reactions other than two minor ones. First, BHT can cause hives in some people who are sensitive to it. Second, BHT can cause a temporary decrease in blood clotting when people first begin taking it in substantial doses.

A check of the scientific literature revealed that allergic sensitivities to food additives such as dyes and preservatives are occasionally reported, but the role of these additives in precipitating chronic urticaria (hives) or other symptoms is still a matter of debate ^13, 14. Only a few cases over the years have identified low-level BHT intake as the sole cause of hives ^15, 16, so this reaction is not likely to be very common; however, it might become more common if provoked by large doses of BHT. Fortunately, the condition tends to clear up after BHT use is halted. In general, however, people with a history of asthma or allergies should exercise appropriate caution when trying BHT. Consulting with a physician is recommended.

As for the transient blood-thinning effect, Steve cautioned that people who have never taken BHT before should acclimatize themselves by starting out with small doses (less than 250 mg for the first day, if possible) and ramping up gradually over the course of a week; there is a special need for caution among those who are taking anticoagulants at the same time. In no case should the final dose exceed 1 gram per day without medical supervision. BHT’s anticlotting effect will diminish within 2 days in any event, unless extremely high doses (around 5 grams per day or higher) are being taken.

But what about liver toxicity? BHT gets metabolized in the liver, so won’t taking large amounts compromise liver function? Steve’s response was that he has spoken with literally hundreds of people who have successfully treated themselves for herpes with BHT. So long as a dose level of 1 gram per day was not exceeded, no cases of hepatic injury (as determined by pathologically high serum levels of the liver enzymes ALT and AST) have yet been reported by this group.

Unfortunately, some people taking BHT will find that not even 1 gram per day is sufficient to eradicate herpes. According to Steve Fowkes, the problem lies not with BHT but rather with the individual-the more unbalanced a person’s metabolic state, the less effective BHT seems to become. Rather than increasing the dose to more than a gram per day, Steve suggests maintaining the BHT level while supplementing with additional nutrients, including vitamins B12 and B6, polyunsaturated fatty acids, magnesium, and selenium; vitamin A is also suggested, although women who are capable of getting pregnant should limit their intake of this vitamin. In addition, anyone who suspects they are hypometabolic should arrange to have a thyroid test done, since hypothyroidism can increase the body’s viral susceptibility.

Finally, Steve suggested that the combination of BHT with hypericin (from St. John’s Wort) is a synergistic antiviral combination, more effective than BHT alone. To determine an appropriate dose level, hypericin intake should be ramped up gradually from 1 mg per day until an effective dose is reached, usually 10 mg per day or less. Steve also recommended pulsing the hypericin at the effective dose level, i.e., using it for about a week at a time with time off between dosing episodes. Because hypericin can cause photosensitivity of the skin, sun exposure should be limited to half the usual daily amount during and after hypericin intake. One of the nice features of BHT is that it tends to inhibit any oxidative stress induced by hypericin; for this reason, Steve feels that anyone taking hypericin should always take BHT with it. For more information on hypericin see the article elsewhere on this website.

After talking with Steve Fowkes and reviewing the scientific literature, I’ve concluded that the benefits of taking BHT seem to greatly outweigh the risks. See also my comments in Questions & Answers About BHT Safety. In the process of researching this article I was reminded of the fundamental principle of toxicology first enunciated around 500 years ago by Paracelsus, the great Renaissance physician and alchemist: “All substances are poisons; there is none which is not a poison. The correct dose differentiates a poison from a remedy.” Or in the present case, “the correct dose differentiates a remedy from a food additive.”

Questions & Answers About BHT Safety

Why should I take an antioxidant which is a synthetic chemical? Wouldn’t a natural product like vitamin E work just as well?

It may surprise you to learn that much of the vitamin E on the market is synthetic, as is most of the vitamin C. Vitamins are chemicals, too, as are all components of the food we eat. Bruce Ames—inventor of the famous Ames test for mutagenicity—put it this way: “There is a tendency for non-scientists to think of chemicals as being only synthetic, and to characterize synthetic chemicals as toxic, as if every natural chemical were not also toxic at some dose.” ¹⁷

By the way, combining BHT with vitamin C (synthetic or otherwise) might be the best way to extend its beneficial effects. Ascorbate has been shown to recycle the phenoxyl radical generated from BHT so that BHT is returned to its original form as an antioxidant ¹⁸. John Mann and Steven Fowkes’ book Wipe Out Herpes with BHT recommends 1 to 4 grams of vitamin C per day in divided doses as an adjunct to BHT ⁴. In view of the fact that BHT is active in membranes, it might be especially helpful to use a membrane-soluble form of vitamin C such as ascorbyl palmitate. As for vitamin E, the jury’s still out. My friend Roger used it and other antioxidants before trying BHT. Roger observed some beneficial effects against herpes but ultimately concluded that the antiviral potency of vitamin E was much less than that of BHT. Steve Fowkes thinks that vitamin E might actually encourage rather than suppress herpes eruptions, but we’ll have to wait for his updated book on herpes to appreciate the metabolic mechanisms involved.

I’ve heard that BHT causes cancer. Is it true?

The International Agency for Research on Cancer (IARC) is part of the World Health Organization. Among other activities, IARC publishes a series of monographs that provide independent, expert assessments of the risks posed to humans by a variety of suspected carcinogens. In its BHT review, IARC could find no consistent evidence that BHT causes cancer in rodents, nor could it find any data showing that BHT causes cancer in humans ¹⁹.

As noted by the authors of the report, one study on mice and another on rats showed no difference in the incidence of tumors among treated and control groups. In another study with a small number of animals, BHT increased the number of mice with lung tumors, but the effect disappeared when the researcher repeated the experiment with a larger number of animals. BHT did cause liver tumors in one experiment, but the IARC experts could not evaluate this study because the rats that had received BHT lived longer than the controls! To confuse matters even further, other studies in mice and rats showed an increased incidence of tumors in females at the lower dose level but not at the higher. Finally, when BHT was tested to see if it could modify the activity of known carcinogens, the results were again all over the map-BHT either enhanced, inhibited, or had no effect on carcinogenicity ¹⁹.

One reason for the haphazard nature of these results is that some of the studies were too small to be reliable; another is that different strains of rats and mice have varying degrees of sensitivity to BHT. But there’s still another reason for not trusting rodent tests. As argued forcefully by Bruce Ames, an internationally recognized authority on DNA mutation and cancer, high-dose tests of suspected carcinogens in rodents are inherently misleading ²⁰. For chemicals that are not mutagenic (i.e., DNA-damaging), feeding the maximum tolerated dose to an animal can cause cancer indirectly by injuring tissues. As the damaged liver or other organ tries to repair itself, cell division increases which in turn increases the rate of spontaneous mutations. Repeated injuries of this kind can lead to increased incidence of tumors. Ames concludes that at doses where cell killing does not occur, chemicals found to be carcinogenic in rodent tests may actually pose a much smaller hazard to humans than is commonly believed ²⁰. His words apply specifically in the present case, since BHT is not a mutagen and does not appear to damage human cells at moderate doses (for example, at 1 gram per day or less).

Far from causing cancer, BHT actually seems to prevent it. For one thing, dietary BHT has been shown to inhibit binding of aflatoxin B1 to DNA ²¹ and to inhibit the development of liver cancer caused by this mutagen ²². Aflatoxin B1 is a highly potent natural carcinogen found in nut molds. The mechanism of protection by BHT appears to involve the activation of liver enzymes such as glutathione-S-tranferase which facilitate the detoxification of xenobiotics (chemicals foreign to the body) ²¹. In addition, the Ames test for mutagenic activity shows that BHT is antimutagenic in the sense that it reduces DNA damage induced by promutagens, i.e., by chemicals requiring metabolic activation to become mutagenic ²³.

The best evidence for the anticancer effects of BHT comes from a study of dogs ²⁴. In an attempt to prevent canine distemper, a dog breeder fed his animals a daily ration of 1 tablespoon of BHT, equivalent to about 10 grams ⁴. The breed was one which is genetically prone to bone cancer and usually does not survive longer than 4 to 6 years. Although the control dogs died at ages 4 through 6, the dogs treated with BHT lived much longer (8 to 10 years) and none of them died of cancer.

Doesn’t BHT raise serum lipids? My cholesterol’s high enough as it is.

You may be thinking of an old report in the Australian Journal of Experimental Biology and Medical Science which sometimes gets cited as evidence of BHT toxicity. The paper stated that whereas BHT alone was harmless to animals, the combination of BHT and a high fat diet caused marked elevation in serum cholesterol. More than four decades later, however, the general consensus is that BHT protects against the development of atherosclerosis rather than causes it, despite the presence of high serum lipid levels. For example, researchers at the Karolinska Institute in Sweden showed that rabbits fed a high-cholesterol diet plus BHT had less severe aortic lesions than rabbits fed the high-cholesterol diet without BHT ²⁵. The same group also demonstrated that BHT prevented the clogging of microvessels (arterioles) by a high-cholesterol diet ²⁶ and markedly inhibited thickening of the lining of the aorta in response to injury ²⁷. These results help support the theory that the damaging effects of cholesterol are due to oxidized cholesterol products and not to cholesterol itself. Of course, if elevated serum cholesterol is a concern, it might not be a bad idea to limit one’s fat intake-but then a low fat diet might be a good idea for anyone with high cholesterol, whether they’re taking BHT or not.

Are there any drugs or medicines I should avoid while taking BHT? I’ve read that alcohol or barbiturates don’t mix with it.

As mentioned earlier, one of BHT’s effects is to induce the expression of liver enzymes which detoxify xenobiotics (foreign chemicals). Some of the enzymes BHT induces are cytochromes known as CYP2A and CYP2B ²⁸. These enzymes are also induced by cocaine ²⁹, by phenobarbital and other barbiturates ³⁰, by ethanol ³¹, and by medications such as phenytoin ³⁰ and imipramine ³², among others. Interactions between BHT and various drugs can excessively activate the cytochrome system with potentially harmful consequences-for example, BHT has been shown to exacerbate the liver toxicity of cocaine ³³. It’s also possible that other interactions among pharmaceuticals, BHT, and the xenobiotic-metabolizing system may impair the effectiveness of some medications. For this reason it is best to avoid combining BHT with certain drugs and medications. Anyone taking prescription drugs, especially anti-seizure medications, benzodiazepines, and tricyclic antidepressants, should consult a physician or pharmacist to determine the likelihood of drug interactions with BHT.