Consumer Reports Highlights Dietary Supplement Dangers Side effects and mixing with other medications are some of the concerns.

 -- A daily supplement or two has become routine for many Americans, but a report is highlighting how these substances can sometimes be harmful.

Consumer Reports outlines in a extensive report how producers of dietary supplements face little regulation from the U.S. Food and Drug Administration and why that can be dangerous for those taking supplements.

Supplements can have side effects, and retailers and pharmacists may not understand how supplements can interact with a person's medication, the report said. Additionally, since supplements are regulated as food, the ingredients do not have to be proved safe and effective in the same manner prescription drugs are by the FDA.

Ellen Kunes, the health editor at Consumer Reports, said consumers can't rely solely on the labels of supplements because they aren't bound by the same regulations as pharmaceuticals.

"Supplements have labels that don’t necessarily tell you what they are good for, how they are going to work, whether they will work," she said. "You can’t trust that they're going to work or that they will be safe just by looking at the label."

Consumer Reports found that an estimated 23,000 people every year end up in emergency rooms after taking supplements.

Dr. Marvin Lipman, Consumer Reports' chief medical adviser, pointed out that worried consumers can look for the USP (U.S. Pharmacopeia) label that means a company has verified what is on the label.

"There’s a paucity of products that are taking advantage of the approval process for responsible companies," he said. "Without verification, you cannot be sure that what's on the label is in the bottle."

Dr. Donna Seger, the director of the Tennessee Poison Center, said that many people do not think about supplements' potential consequences on their health. She said people shouldn't think of these substances as innocuous and should always check with their doctors before taking them.

"People shouldn't be taking supplements who are on medication unless they checked with their doctor," she said, adding that ingredient consistency can be an issue too. "If you have 100 pills in a bottle, there might be a different amount in each pill."

The Council for Responsible Nutrition, a leading trade association for the dietary supplement and functional food industry, disagreed with the report, pointing out that 150 million Americans take supplements.

"Overwhelmingly, dietary supplements are safe and play a valuable role in helping Americans live healthy lifestyles," the council said in a statement. "The industry is regulated by the FDA, and the robust regulations give the government the ability to remove unsafe products from the market. It is patently illegal for products to be sold as dietary supplements if they contain prescriptions or illegal drugs, and we urge the government to use its enforcement authority to protect consumers from those products."

Consumer Reports pointed out 15 ingredients in supplements that it says consumers should avoid because they have dangerous side effects such as rapid heartbeat, liver damage and seizures:

Aconite

Caffeine powder

Chaparral

Coltsfoot

Comfrey

Germander

Greater celandine

Green tea extract powder

Kava

Lobelia

Methylsynephrine

Pennyroyal oil

Red yeast rice

Usnic acid

Yohimbe