Weight loss supplements claiming to have "all natural" ingredients are popular.
But unlike medications, supplements, whether they are natural or not, are not regulated by the Food and Drug Administration. So, it is always a good idea to check the ingredient list with your doctor before taking herbal supplements.
"I think it's important to know things that are natural doesn't necessarily mean it's good for you," cardiologist, Dr. David Sandler said. "It doesn't necessarily mean it's bad for you either, but being natural isn't by itself a certification of good for you."
The 2NEWS Problem Solvers asked the Oklahoma State Poison Control Office to look at common ingredients found in many natural herbal weight loss supplements.
Herbs and extracts in the supplements can affect prescription medications and certain medical conditions.
For instance, grapefruit juice, powder or extract found in some of the weight loss supplements can affect the way many common prescription medications work.
"It interferes with the way the liver metabolizes our drugs so it's important to know what's in the medications we're taking and what's in our supplements as well," Sandler said.
Here are some more findings from the Poison Control Center:
Green Tea, green tea extract, green coffee extract, guarana and caffeine anhydrosus are high in caffeine. Too much caffeine can cause your heart to race. That can be dangerous for people with certain heart conditions. Caffeine can also cause people to feel jittery or shaky. It can have a diuretic effect that may interfere with some prescription medications. Additionally, caffeine can raise blood pressure which is of concern to people with hypertension.
The Poison Control Center said ginkgo biloba is a more widely studied supplement. The primary concern with this herb is the potential for drug interactions. Gingko biloba and another common herb, ginseng, can increase the risk of bleeding for people taking warfarin (Coumadin), aspirin and other medications that effect blood clotting.
Some supplements put ingredients lists on the the label, others do not. Some include warnings for people with specific medical conditions or taking certain drugs, others do not. And, some put the warning in such small type they can easily be overlooked.
"With most ingredients either they're safe or very little is known,"Scott Schaeffer, from the Poison Control Center said. "I know that's not an entirely satisfying answer, but the manufacturers of these products put together so many different combination of herbs and ingredients that research can't keep up with them."