Conjugated Linoleic Acid (CLA)

Medically Reviewed by Melinda Ratini, MS, DO on May 30, 2023
2 min read

CLA is an essential fatty acid that's important for good health. We get small amounts of it from the food we eat. It's also an antioxidant that may have other health benefits.

Studies show that CLA supplements may help people who are obese. But it's complicated. CLA may decrease body fat. It may help people feel fuller after eating. However, it doesn't seem to lower a person's weight or BMI. For now, if you're looking to lose weight, there's not enough evidence to show that taking CLA will help.

As an antioxidant, CLA may have cancer-fighting properties. Studies have shown that women who get a lot of CLA from their diets have a lower risk of colorectal cancer; they may also have a lower risk of breast cancer. However, we don't know if taking CLA supplements would have these benefits, too. More research is needed.

CLA does seem to lower bad LDL cholesterol. But since it also lowers good HDL cholesterol, it's not a standard treatment.

People take CLA supplements for other reasons, ranging from dry skin to multiple sclerosis (MS). We don't know if CLA will help with these conditions.

There's no standard dose for CLA. For obesity, dosages may range from 1 gram to 6.8 grams daily, much higher than the amount of CLA in a typical diet. Ask your doctor for advice.

CLA is in many animal products, like milk, beef, and other meat. Grass-fed beef may have higher levels of CLA than grain-fed beef. It's also in sunflower and safflower oil. Cooking food may increase levels of CLA.

Tell your doctor about any supplements you’re taking, even if they’re natural. That way, your doctor can check on any potential side effects or interactions with medications.

  • Side effects. CLA supplements may cause upset stomach, nausea, diarrhea, and fatigue.
  • Risks. CLA supplements may worsen insulin resistance, or how your body absorbs sugar, in people with diabetes or metabolic syndrome. Given the lack of evidence about its safety, doctors don't recommend CLA for children or for women who are pregnant or breastfeeding. It may cause dangerous effects on the liver. It may lower HDL, or good cholesterol. Some research has also documented an increase in inflammation with the use of CLA supplements.
  • Interactions. If you take any medicines regularly, talk to your doctor before you start using CLA supplements. 

The U.S. Food and Drug Administration (FDA) does regulate dietary supplements; however, it uses a different set of regulations than "conventional" foods or drugs. Unlike drug manufacturers, the makers of supplements don’t have to show their products are safe or effective before selling them on the market.