Auburn, March 15---Dietary supplements are fraught with risk, experts say.

It is a fact reflected in the lives of three women whose lives have been permanently changed because of supplement use.

One American woman suffered permanent liver damage, while the other two, both Swedish, developed unwanted pregnancies after using herbal supplements.

What many people often overlook is the fact that many supplements considered "natural" and "safe" actually may contain all sorts of substances, even prescription drugs that interfere with other drugs or produce long-term, even life-threatening, health problems.

"When you take these supplements, you really don’t know what you’re getting," says Dr. Robert Keith, an Alabama Cooperative Extension System nutritionist.

This is because the supplement industry, unlike the drug industry, is largely unregulated, and supplements do not have to be tested prior to release, he says.

"With a prescription drug, you pretty much know what you’re getting in the way of possible side effects and interactions with other drugs, because these drugs have been rigorously tested prior to release," Keith says. "But with supplements, you’re talking about a product that can be released before any tests are made."

The three women learned this fact the hard way. The 45-year-old woman suffering permanent liver damage became so seriously ill within a few months that doctors concluded she will need a liver transplant to survive. Prior to her illness, she was consuming Kava, a popular herbal drink that supposedly relieves stress by producing a sense of calmness.

European health authorities report 25 similar cases of liver damage associated with kava use. The supplement already has been banned in some countries, even though kava parties and even bars are the rage throughout the United States.

Sweden’s pharmaceutical regulator also issued a warning about herbal supplements after two Swedish women developed unwanted pregnancies from consuming St. John’s wort, which is often used to relieve mild forms of depression.

The women, aged 28 and 32, were not aware St. John’s wort can interfere with hormone-based contraceptives. St. John’s wort is also believed to reduce the effectiveness of other drugs, including HIV medicines, blood thickening drugs and cyclosporine, used to prevent the rejection of organ transplants.

Nevertheless, many countries, including the United States, do not require supplement manufacturers to carry label warnings about these popular interactions.

Other supplements may even contain traces of prescription drugs, such as warfarin, a powerful blood anticoagulant.

Keith suspects anti-depressants and anti-anxiety drugs are among several types of substances put into supplements merely to trick buyers into believing they are getting a big bang for their bucks.

"I can’t think of any other reason why they would put these drugs in a product unless they were trying to create some biological effect, so that people using these products would actually think they are working," he says.

In many cases, supplement manufacturers are often able to go undetected for years unless someone gets sick consuming their products.

Even in cases where products do not contain harmful substances, it is possible consumers are not getting what is advertised on the label.

Testing by Consumer Reports, for example, revealed that roughly 25 percent of these supplement products may not contain the concentration of the herb or supplement advertised on the product label.

"It’s just like the Old West when saloon owners watered down their drinks to inflate their profits," Keith says. "Without regulatory oversight, many supplement manufacturers have a strong incentive do the same thing, because, after all, who is watching them?"

Keith offers this advice to consumers. First, when buying supplements, buy only name-brand products. Big companies have their reputation invested in these products and, therefore, have less incentive to tamper with them.

Likewise, avoid products produced by obscure companies.

"In some cases, these may not be "companies" at all, but one-person outfits operating out of, say, a vacant garage," Keith says.

Second, stick with nutrients, such as vitamins C and E and folic acid, and avoid many herbal supplements entirely, especially exotic supplements that appear to make fantastic claims.