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Herbs, Supplements and HIV

August, 2000

Vitamins, supplements and herbs have long been used by people with HIV in hopes of helping manage side effects of other therapies and/or improve overall general health. In fact, studies suggest that upward of 70% of people living with HIV and about 50% of the general population use some form of complementary therapy, with the most common being approaches such as massage and acupuncture. Unfortunately, not many approaches have been studied in people with HIV or looked at to see how they might interact with commonly used medications, or whether they add to the overall benefits of therapy. Recently, a number of reports have questioned the safety of some complementary approaches in the setting of HIV and beyond.

The intention of this article is not to discourage the use of complementary therapy, but rather to supply some food for thought when contemplating decisions about these remedies. The companies that promote herbs, supplements and vitamins advertise the potential benefits of the products but the consumer has very little information about the products themselves -- their true value for treating specific conditions or even information about the actual content of the products they are buying. Promoters of supplements and herbs are often the first to criticize prescription drugs as the products of "big business," but supplements and herbs are themselves part of a huge industry with annual sales of around $20 billion. This article will highlight emerging concerns about the use of various complementary approaches and also address ways to minimize potential risks associated with the use of these therapies, where possible.

A Little Background . . .

Under current law, vitamins, supplements and herbs do not have to be evaluated by any regulatory agency (e.g., the Food and Drug Administration) prior to their sale. All they need do is assert that the product is "generally regarded as safe." What this means is that there is no requirement for studies to demonstrate the effectiveness and safety of these products -- leaving the consumer with little or no meaningful information about benefits or side effects of therapy. Some manufacturers vaguely reference "studies" in their promotional literature, but these are seldom more than very small, uncontrolled studies. Also, these products do not have to be manufactured in accordance with the rigid guidelines established for the manufacturing of pharmaceutical products, called Good Manufacturing Practices. As a consequence, there is extremely wide variability between products in terms of their active ingredients, and even between batches of the same product from a single manufacturer. In fact, studies have shown that some of the products being sold on the market today contain no amount of the claimed active ingredients whatsoever. Other products being sold as herbal supplements have been shown to contain dangerous chemicals (e.g., arsenic and lead, both potentially deadly). Still other products have been shown to actually contain pharmaceutical medications. The best manufacturers, however, make a serious effort to deliver the real product in the amounts claimed, but due to the lack of regulatory requirements, there is no simple way to determine who is telling the truth.

People should be aware of these things and take measures to reduce their risk of buying contaminated products or products without active ingredients by seeking out reputable sellers of herbs, vitamins and supplements. Seek guidance from a trained alternative medicine practicioner (e.g., an herbalist or nutritionist who specializes in HIV) and gather information about the products you are considering using. Taking the word of people selling the product in stores is no guarantee of accuracy. On the actual package, or on their websites, some manufacturers of herbs and supplements will claim that their products have been tested for active ingredients. Do a little research and see what you can learn. For example, some consumer publications, such as Consumer Reports and other similar groups like, periodically test supplements and list what is actually in various brands. Even this, however, doesn't tell you whether the product will benefit you. As a general rule of thumb, if a company has shown integrity in some of its products that have been tested by consumer groups, it is a reasonable sign that they maintain similar standards for other products in their line. According to researchers who are evaluating these therapies, the quality products that undergo evaluation by the manufacturer are in general not the ones that you'll find at your average grocery store or pharmacy.


Drug Interactions

St. John's Wort, a popular over-the-counter herbal supplement (also known as hypericin) used for mild depression, has been shown to have potentially serious interactions with protease inhibitors and non-nucleoside reverse transcriptase inhibitors (NNRTIs). See PI Perspective 29 for more details of this study. This doesn't mean that St. John's Wort doesn't "work" for helping people deal with depression, but rather it poses a serious drug interaction problem that could jeopardize the effectiveness of anti-HIV therapy.

Part of what led researchers to look at St. John's Wort for potential interactions with anti-HIV therapy is that the herb is processed in the body by the same enzyme used for processing many drugs, including protease inhibitors and most NNRTIs. This enzyme is called the p450 enzyme. A number of dietary supplements and herbs have reported effects on the p450 enzyme. Depending on how they interact with p450, using anti-HIV therapies with these products could lower the blood levels of the anti-HIV therapies (possibly putting people at risk for developing resistance to their anti-HIV drugs) or they could increase the blood levels of the anti-HIV therapies (putting people at greater risk for serious side effects). Herbs with reported effects on the p450 enzyme include:

  • St. John's Wort

  • Garlic

  • Ginseng

  • Melatonin

  • Milk Thistle (silymarin)

  • Geniposide

  • Skullcap

Dr. Piscitelli of the National Institutes of Health (NIH) is championing a series of interaction studies to provide people with HIV information to enhance the safe use of complementary therapies with anti-HIV medication. In a recent presentation, Piscitelli noted that the most common supplement used by people attending the NIH's HIV clinic is garlic. Piscitelli will evaluate this in future studies. A woman recently initiated a ritonavir (Norvir)-containing anti-HIV regimen and then began garlic supplementation. After starting the garlic, she developed severe nausea and vomiting which resolved after she stopped the garlic. It may be that garlic increased the levels of ritonavir, and thus its side effects. There has also been a second report where it appears garlic supplementation may have enhanced the side effects associated with ritonavir. Garlic may also increase the risk of side effects associated with other anti-HIV therapies. This information, coupled with knowledge that garlic has a reported effect on p450, suggests that until more is known people should use caution when combining high doses of garlic with anti-HIV therapies that use the p450 pathway (e.g., protease inhibitors and NNRTIs). Moreover, people using the supplement with anti-HIV drugs who experience serious stomach problems (diarrhea, nausea or vomiting) might consider discontinuing it to see if these symptoms lessen.

According to a recent article in the medical journal The Lancet, there are a number of reported herb-drug interactions that include the following herbs:

  • Betel Nut
  • Devil's claw
  • Garlic
  • Ginseng
  • Kava
  • Psyllium
  • Saiboku-to
  • Sho-saiko-to
  • Valerian
  • Chili Pepper
  • Dong quai
  • Ginkgo
  • Guar gum
  • Papaya
  • St. John's Wort
  • Shankhapushpi
  • Xiao chai hu tang
  • Yohimbine

To lessen the likelihood of herb-drug interactions, Dr. Piscitelli encourages people to have more in-depth discussions about the use of complementary therapy with their doctors and pharmacists. This may take some getting used to for both patients and doctors. Doctors may need to learn to listen and support their patients, in a nonjudgmental way, about the use of complementary therapy. Undoubtedly it may well be patients who drive this learning curve. Patients need to be open and honest about what they are using and considering. The only way to capture information about drug interactions and side effects is if they are recorded in a complete drug history, including herbs, vitamins and supplements that you are using. It's also important for patients, doctors and pharmacists to keep up on the latest information about drug-herb interaction studies.

What About Side Effects?

The biggest myth about complementary therapies is that they are non-toxic. There is a widely held misconception that because something is natural, or sold over-the-counter, that it doesn't have side effects. To the contrary, there have been numerous reported cases of people with HIV experiencing side effects from complementary therapy. Chinese herb preparations that contain deer antler, for example, can cause nausea, diarrhea and other kinds of stomach upset. One man stopped all his anti-HIV medication in an attempt to determine which of his medicines was upsetting his stomach and quality of life. It turned out that when he stopped his Chinese herbal preparation (that contained deer antler), his problems cleared -- it wasn't the anti-HIV therapies causing the problems at all. High doses of vitamin C can cause severe diarrhea. Taking too many B vitamins can lead to a complication that lands one in the hospital and excessive levels of vitamin A can be highly toxic to the liver. Side effects associated with herbs, vitamins and supplements might not reveal themselves immediately. It may take a number of weeks after starting a therapy for side effects to emerge as a problem. Keeping an accurate record of every therapy you are taking, including when you start and stop therapies and documenting the onset of side effects may help to sort out which therapy is causing the problem.

The following is a list of herbs with known serious side effects:

HerbKnown toxicity







Life root

Liver toxicity

Kidney toxicity

Liver toxicity, light sensitivity

Vaso-occlusive disease

Heart failure, stroke, hypertension

Inflammation of the liver (hepatitis)

Veno-occlusive disease

Below is a list of vitamins with known side effects.

VitaminPotential Side Effects of Supplementation
Vitamin A and beta-carotenePerhaps the most toxic vitamin. At high doses (greater than 25,000 IU per day) toxicities are more likely, including loss of appetite, weight loss, bone malformations, spontaneous fractures, internal bleeding, liver toxicities and birth defects.
Vitamin B-6 (pyridoxine) Reversible neuropathy has been reported in people taking high doses (500mg to 6 grams a day) over extended periods of time.
Vitamin B-12 In very rare instances, allergic reactions have been reported.
FolateHigh doses have been associated with reduced zinc absorption.
Vitamin C High doses can cause diarrhea and gastrointestinal distress. Buffered formulations are available and may decrease stomach problems. People with a history of kidney stones should consult a physician before taking high doses.
Vitamin D Potentially very toxic; can cause bone lesions. Toxicities reported with single high dose supplementation.
ThiaminVery high intravenous doses have caused intoxication, headache, convulsions, muscular weakness, paralysis and cardiac arrhythmias.
BiotinNo reported toxicities.
Vitamin E No reported toxicities.
RiboflavinNo reported toxicities.
Pantothenic Acid No reported toxicities in humans.
Vitamin K No reported toxicities in humans.
NiacinToxicites may be related to formulation. Nicotinic acid can cause itching, nausea, vasodilation and vomiting at doses of 2 to 4 grams/day. Nicotinamide only rarely produces these toxicities.

Unlike pharmaceutical products, large studies are not required to document side effects associated with complementary therapy and potential side effects are typically not noted on the package materials. The key to minimizing the risk of potential side effects with these therapies is to learn about them, monitor for early signs and implement measures to minimize the risk.

Buyer Beware!

Recently, a number of Chinese herb supplements to manage diabetes have been pulled from the shelves by the California Food and Drug Board (FDB), a state equivalent to the Food and Drug Administration (FDA). The action followed an incident where a person with diabetes was hospitalized after taking one of the supplements. The supplements were tested and found to contain pharmaceutical medication used to treat diabetes. The additional medication in the claimed "natural" product lead to an overdose of medication for the individual.

There are numerous herbal remedies that contain controlled and potentially dangerous substances that are banned by the FDA. The FDA readily admits that it simply doesn't have the enforcement potential to ensure that these products stay off the shelves of some stores. Media exposés on this topic in California reveal countless tales of people harmed by such products that contain lead, arsenic, anabolic steroids and other controlled and potentially dangerous substances.

To protect yourself, seek reputable sellers, investigate the product and seek guidance from trained professionals.


Herbal remedies and other vitamins are sold as "food supplements" and do not undergo the rigorous testing that other medications do. They are not regulated and may not reveal on the label all of the product's contents, nor do they necessarily contain the ingredient listed or the amount of it claimed. Don't assume that simply because something is available over-the-counter or is natural that it doesn't have side effects or won't interact negatively with other medications that you are taking.

In the United States alone, it's estimated that $20 billion dollars were spent on complementary therapies last year. The use of complementary therapies has risen almost 400% in the past eight years and it's estimated that 50% of people in the U.S. use complementary therapies. The sale of complementary products is an ever growing industry and at the current time that industry has done very little to document the safe and effective use of its products. It's unlikely that it ever will. The U.S. Government, through the NIH, has established two botanical centers to evaluate complementary and alternative therapies with a budget of $68 million dollars. A third center will be funded shortly. Every few years, new discussions are held about whether and how to better regulate the marketing of nutritional supplements and herbs.

There is a great difficulty in evaluating herbs and herb-drug interactions because often times the active ingredient of the products and its dose are not known. Moreover, drug interaction studies for pharmaceutical products typically take a matter of a week to ten days. Drug-herb interaction studies are expected to take much longer, and as a consequence be more expensive, as it's likely that people will have to be taking herbs for a matter of weeks before an effect is seen. Even when the interactions are determined for one particular product, it is unclear how they will relate to other similar products because of the lack of control over dosing. Because no studies have determined the appropriate or best dose of many complementary therapies, researchers face an additional challenge in first selecting the dose of herbs to use in studies. Necessary funding for the studies will remain a problem and limitation to moving forward rapidly. Many companies selling herbal and other complementary approaches are reluctant to fund studies that may reveal that their products are not useful, have side effects or have interactions with commonly used medications. This information could hurt their "bottom line" of profit. Pharmaceutical companies are also unwilling to fund these studies for many of the same reasons, and the FDA does not require them.

Whatever the possible benefits of herbs, vitamins and supplements, there simply is no information to guide decision-making with regard to using these remedies. Be aware that using them entails some element of risk.

Back to the Project Inform Perspective August 2000 contents page.

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This article was provided by Project Inform. It is a part of the publication Project Inform Perspective. Visit Project Inform's website to find out more about their activities, publications and services.
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