Dietary Supplements Can Cause Liver Damage
More Research and Regulation Is Needed

Medical Author: Tse-Ling Fong, MD
Medical Editor: Leslie J. Schoenfield, MD, PhD
Medical Reviewing Editor: Dennis Lee, MD

Dietary supplements, which are also referred to as health supplements, include herbal products, vitamins, minerals, and any product that is not being marketed as a food or drug (medication). People take dietary supplements with the idea of maintaining or improving their health. Recently, however, my colleagues and I reported in a medical journal a series of seven patients who were referred to us with severe liver injury. They developed the liver damage after taking a health supplement called Lipokinetix® to lose weight. This supplement is a mixture of chemicals that includes an extract from a particular tea. It is said to reduce weight by working to mimic exercise and increase metabolism.

How and why can dietary supplements damage the liver? Within three months of starting Lipokinetix, these seven patients developed symptoms of acute hepatitis, including tiredness, loss of appetite, and abdominal pain. They sought medical attention and their blood tests revealed severe liver damage. One of the patients actually developed acute (rapid) liver failure and almost required a liver transplant to save her life. After being in a coma for three days, she miraculously recovered and was able to leave the hospital. Indeed, in all seven patients, the symptoms disappeared and the liver tests returned to normal within several months after discontinuing Lipokinetix. That said, I have since been informed of another individual who took this same supplement, developed acute liver failure, and did require a liver transplant. She is doing well now. However, so that her body can continue to accept the new (foreign) liver, she will be taking powerful anti-rejection medications for the rest of her life.

But that's not all! Numerous instances have been reported in the medical literature of dietary supplements, especially herbal products, causing liver damage. These supplements include kava (which has received much recent coverage in the press), Jin Bu Huan, germander, chaparral, shark cartilage, and mistletoe, to name a few. Dietary supplements can cause liver injury in a number of different ways. In some instances, for example with kava, liver injury is dose-related. That is, the higher the dose, the more often liver damage occurs. In many instances, however, liver injury is an unpredictable peculiarity in an individual (an idiosyncratic reaction).

It is well known that people often take combinations of herbal and/or other dietary supplements. In this circumstance, if a person develops severe liver injury, identifying which supplement is the specific culprit is very difficult. What's more, as the dietary supplement market becomes more competitive, the manufacturers of supplements are mixing and matching their products and doing so in proportions that have never before been tried. A case in point is the above-mentioned Lipokinetix, which contains among its ingredients an ephedrine-like stimulant, a type of thyroid hormone, and the tea extract.

The main problem is that the Food and Drug Administration (FDA) does not regulate the manufacturing process for dietary supplements, as it does for conventional drugs. You see, the FDA cannot consider a dietary supplement to be a food or a drug. Thus, the purity of dietary supplements is determined and reported to the public by the manufacturer only. Moreover, the dosage of these supplements is determined by the manufacturer and is often without scientific support or data that is published in peer reviewed scientific journals. Furthermore, the FDA requires no pre-marketing animal or clinical testing of dietary supplements, as it does for conventional drugs. Additionally, physicians report adverse events only voluntarily when they happen to encounter them.

Therefore, as long as the manufacturer does not make an outrageous claim about their product, and does not market the product as a food or a drug, these supplements end up on the store shelves without much, if any, scrutiny by the FDA. It turns out that designating a health product as a dietary supplement is a loophole created by the 1994 Dietary Supplements Health and Education Act. (The term "dietary supplement" implies an addition to the diet of something that is already present in the food we eat.) This loophole enables the producers of dietary supplements to avoid FDA regulation of the manufacturing of these products. Well, this situation regarding the rather loose regulation of dietary supplements makes me nervous. I am concerned, especially when considering that conventional drugs (medications) are subjected to a fairly rigorous review process.

What is the review process for conventional drugs? For a drug to be released on the market in the U.S., it must go through many steps, including extensive testing in animals and three phases of clinical testing in people. In the first phase, the drug is given to healthy subjects to determine the potential for adverse effects (toxicity). In doing this, different doses of the drug are tested to ensure that even a dose that is several times greater than the intended dose is safe in humans.