If you’re not familiar with Conjugated Linoleic Acid (CLA) it is a naturally occurring omega 6 fatty acid found in dairy and meat products.
Foods high in CLA include grass-fed beef and dairies such as butter, milk, yogurt, and cheese.
CLA is also widely sold over the counter and online as a syrup or pill dietary supplement that claims to help people burn fat, maintain weight loss, and manage type 2 diabetes, which is common in individuals with obesity.
Conjugated linoleic acid supplements were first introduced in the market in the early 2000s after studies  found CLA to be effective in burning body fat in animals.
Since then there have been a lot of studies seeking to find out whether CLA does burn fat and help humans lose weight.
In this post, I’ll tell you if CLA delivers the weight loss results it promises, if it does, how effective it is, and answer any safety concerns you might have about using conjugated linoleic acid supplements.
Does CLA Actually Work for Weight Loss?
In short, more research may be needed: most of the research conducted on conjugated linoleic acid so far has found limited evidence that it directly leads to weight loss.
For example, a review of 18 CLA studies  concluded that the average weight loss conjugated linoleic acid caused was 0.2 pounds (0.090 kg) per week. And that was for the first six months, after which the weight loss plateaued for close to two years.
The review also found that the source and amount of CLA taken determines the weight loss benefits gained.
Grass-fed beef and dairy  , which contains 3 to 5 times more conjugated linoleic acid than grain-fed beef and dairy, helps burn more fat.
Other sources, however, do appear to back CLA’s use to help reduce body fat: according to research published in The American Journal of Clinical Nutrition, “Long-term supplementation with CLA-FFA or CLA-triacylglycerol reduces BFM [body fat mass] in healthy overweight adults.”
There have also been promising early studies around CLA’s ability to improve body composition and weight loss, but most have been done on animals, and the results for humans haven’t been as clear. In general, more research is needed to clearly show its efficacy.
For a person to register some weight loss, most studies found that at least 3 grams of CLA  was needed daily.
CLA does provide other health benefits such as:
- A stronger immune system. CLA has anti-inflammatory properties which can help the body better fight off infections.
- Increased bone strength. It does this by increasing the body’s uptake of calcium and reducing the activity of osteoclasts cells that wear down bones.
- A healthier heart. Studies have found that CLA prevents the build-up of fatty plaques in the arteries which could cause a heart attack or stroke.
How Does Conjugated Linoleic Acid Help Burn Fat?
Different studies  have found there are three main ways conjugated linoleic acid can help in weight loss.
- When you consume CLA it may help you reduce weight by stimulating thermogenesis, which makes your body burn more calories throughout the day.
Research on the impact of CLA on the metabolism involving two groups of overweight people, one group using 3.2g of CLA supplements and the other placebos, found that people using the supplements burned fat more efficiently  compared to those on the placebo.
- Conjugated linoleic acid also controls the PPAR-gamma receptors  stopping fat cell production and fat storage.
A two-year study that looked at six individuals that used 3.14g CLA supplements  found that they lost on average 6 pounds (2.7 kg) of body fat in that period due to CLA decreasing their fat stores.
- Lastly, CLA when used by people dieting gives a sense of satiety causing the person to eat less which aids in weight loss.
Is It Safe to Use CLA Supplements for Weight Loss?
You probably already consume conjugated linoleic acid daily throughout your diet.
On average in the US, men ingest about 212mg of CLA per day  , while women intake 151mg.
People who get a lot of CLA from natural foods have been found to have improved metabolic health and a lower risk of getting various diseases including heart disease, cancer, and type 2 diabetes  .
At a higher dosage CLA supplements may, however, cause some serious side effects because they are made from chemically altering linoleic acid found in vegetable oils, which is different from the natural CLA in foods. Also, supplements have much higher conjugated linoleic acid amounts than what is in beef, milk, cheese, butter, etc. The larger amounts can lead to increased fat accumulation in the liver, causing metabolic syndrome  and diabetes.
Conjugated linoleic acid supplements could also cause mild side effects such as oxidative stress, diarrhea, and insulin resistance.
That said, the Food and Drug Administration (FDA) gives CLA supplements a Generally Regards As Safe (GRAS) status.
And research has found up to 6 grams of CLA per day doesn’t cause serious side effects. So, moderately used conjugated linoleic acid supplements are safe.
Who can use CLA supplements?
If you’re in good health you can use conjugated linoleic acid supplements to try burn body fat and improve your body composition.
CLA is also an ideal supplement if you're a vegan or vegetarian, because the body doesn't make the heart-healthy fat it requires in small amounts.
You should avoid CLA supplements if your cholesterol is high because its fat could increase your LDL cholesterol and cause poor heart health.
If you decide to use conjugated linoleic acid supplements to experience its benefits, ensure you stick to under 6 grams per day as a higher dose could cause health problems. Also, CLA supplements are sold in varying concentrations; to get the best weight loss results, it is recommended you buy a product with 80% CLA.
The Bottom Line
Like many health supplements that are marketed for weight loss, CLA has been hyped as one of the latest and greatest weight loss products on the market. But it’s important to note: research to date has not clearly shown the omega fatty acid’s efficacy in burning body fat.
If you choose to use CLA supplements, be sure to do your research first. Make sure you understand the facts, and consult a doctor to find out if it is safe for you to use them.
As with other similar supplements, you’re unlikely to see a significant weight loss change using CLA alone. We suggest you try other proven weight loss methods such as exercise and proper nutrition while using CLA supplements for the best fat-burning results.
- Benjamin S, Prakasan P, Sreedharan S, Wright AD, Spener F. Pros and cons of CLA consumption: an insight from clinical evidences. Nutr Metab (Lond). 2015;12:4. Published 2015 Feb 3. doi:10.1186/1743-7075-12-4