Some people feel nauseous and experience loose stools after taking conjugated linoleic acid, or CLA, supplements such as Tonalin, reports About.com. Individuals can reduce these side effects by taking the supplements with a protein-rich food, such as milk.
CLA supplements are typically used to reduce body fat and help balance blood sugar levels, explains About.com. In one study, a group of overweight women lost 9 percent body fat in one year by taking CLA supplements and not changing their eating or lifestyle habits, according to WebMD. Animal studies have shown that CLA can help protect against heart disease and some cancers. Studies of the safety of CLA supplements have revealed no serious side effects.
CLA is a type of fatty acid that is found naturally in meat and dairy products, explains WebMD. It's sold as a health supplement and comes in both pill and syrup forms. Those interested in taking this supplement are advised to buy a product that contains at least 80 percent CLA in order to experience the maximum weight loss benefits.
Many overweight people who consider taking CLA suffer from thyroid disorders. No evidence suggests that this supplement interferes with thyroid medications, according to About.com, but these individuals are advised to check with their physicians before taking this or any other nutritional supplement.