Tonalin CLA is a dietary supplement that contains conjugated linoleic acid, a chemical found in fatty acids, that is marketed as decreasing body fat. Despite the fact that the makers of Tonalin CLA state that the supplement is "completely safe," conjugated linoleic acid does pose some risks.
The most common side effects of Tonalin CLA are not normally dangerous and include upset stomach, nausea, diarrhea and fatigue, reports RxList.com.
A 2007 study at the University of Guelph found that taking conjugated linoleic acid decreases sensitivity to insulin, the substance in your body that helps control blood sugar levels. In people who are already in danger of developing the disease, decreased insulin sensitivity has the potential to cause the onset of type 2 diabetes.
Conjugated linoleic acid increases the likelihood and duration of bleeding, according to the Physician's Desktop Reference. While this poses only a minor risk in most people, if you suffer a severe accident, require immediate surgery or have another condition that makes you at risk for bleeding, like digestive ulcers, products that contain linoleic acid, like Tonalin CLA, may be dangerous.
Covilhã University Hospital in Portugal reported a case of liver inflammation or hepatitis caused by conjugated linoleic acid in 2008. Some people develop life-threatening allergic reactions to conjugated linoleic acid, resulting in shortness of breath, rapid heart rate and swelling of the face and extremities, reports the Physicians Desktop Reference.
If you are pregnant or nursing or taking blood-thinning medications or if you have diabetes, heart problems or metabolic syndrome, it may not be safe for you to take Tonalin CLA because it contains conjugated linoleic acid.
Because Tonalin CLA is a dietary supplement, its effectiveness and safety are not evaluated or regulated by the U.S. Food and Drug Administration. The makers of Tonalin CLA do not provide a complete list of the product's ingredients, so it is not known if the supplement contains any harmful substances.