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Conjugated Linoleic Acid (CLA) for weight loss

13 Aug 2021 • 3 min read


Conjugated Linoleic Acid (CLA) is naturally present in meat and dairy and has been widely linked to several health benefits, including weight loss.

In this article, we take a closer look at CLA and its connection with weight loss, as well as practical information, such as daily dosage recommendations, side effects and the different types of CLA supplements.

What is Conjugated Linoleic Acid (CLA)?

CLA is an Omega-6 fatty acid found naturally in meat and dairy, especially from grass-fed varieties.

It comes from the Linoleic Acid (LA) that’s in the grass and grains eaten by animals, such as cows and sheep.

CLA supplements are usually made from LA from safflower oil or sunflower oil. It’s altered using chemicals, enzymes or 'friendly' bacteria during the manufacturing process to convert it into CLA.


  • CLA is an Omega-6 fatty acid that comes from the Linoleic Acid in grass and grain eaten by animals
  • The supplement form of CLA derives from safflower or sunflower oil

Can CLA help you lose weight?

Sadly, there’s no magic formula for losing weight, but there are certain supplements that can potentially give your weight loss efforts a helping hand.

One supplement that’s gaining ground is CLA, or Conjugated Linoleic Acid, which is widely reported to help people lose weight (more on this below).

Handpicked content: How long does it actually take to lose weight?

How does CLA work to burn fat?

CLA is thought to trigger a series of chemical reactions that stimulate fat-burning in the body. It’s believed to:

  1. Speed up metabolism

By increasing the amount and rate that the body burns calories and fat. 

As a result, the body increases the amount of calories it burns off and uses its energy stores more efficiently.1

Handpicked content: What is metabolism & can you speed it up?

  1. Increase insulin resistance

Studies have found that having higher levels of CLA in your blood can lead to lower levels of leptin, a hormone believed to regulate fat levels.

High leptin levels may play a role in obesity, one of the biggest risk factors for adult-onset diabetes.2

  1. Help the body ‘mobilise’ stored fat

By helping break down muscles and reduce fluids.

One particular study tested the impact of a 4.5g CLA supplement on fat loss in overweight but otherwise healthy people for a year.

The group that took the CLA supplement lost close to 9% more body fat than the placebo group.3

  1. Kill white (‘bad’) fat cells

CLA’s ability to reduce body fat mass and increase lean muscle mass is yet to be fully understood.

It’s thought to be able to trigger fat cell death, shrink fat cells and potentially speed up metabolism to promote weight loss (as mentioned in point 1).4

CLA for weight loss

One study published in the American Journal of Clinical Nutrition in 2004 found that a group of overweight men and women, who took CLA for a year, lost on average, 9% of their body fat without changing their diet or lifestyle.5

As for the ‘fat burning’ qualities that are widely linked to CLA, animal research has shown that CLA burns fat by increasing the levels of enzymes (lipase) and proteins that are responsible for breaking down fat. Unfortunately, this is yet to be widely proven in humans.6

A randomised control trial was carried out into the impact of 3.2g of CLA on the metabolism of overweight, but otherwise healthy adults.

It revealed those who took the supplement burned fat stores more efficiently and used less protein for energy compared to the placebo group.7

Meanwhile, a separate study explored the impact of 3.76g of CLA on fat burning and energy expenditure for several months.

It concluded that CLA increased the rate of energy expenditure, specifically by increasing the rate at which fat was burnt.8

However, combining CLA with a healthy lifestyle could see even greater results. In 2001, Norwegian scientists followed 20 healthy adults, who exercised for 90 minutes three times a week, for 12 weeks.

Those who took CLA every day lost more body fat than those who only exercised.9 CLA could even aid weight loss while you catch some ZZZs.

Research by the University of Wisconsin-Madison found CLA enhanced fat burning during sleep.10

CLA for weight loss around legs & hips

We’ve been taught that we can’t spot-reduce fat – reduce fat in specific areas – but a study published in the British Journal of Nutrition in 2007 observed that taking CLA appeared to shift fat stored around the legs and hips.11

Another study carried out on 60 men and women in Barcelona found that CLA was shown to target ‘trunk fat’ – in other words, fat around the middle.12

CLA increases lean muscle and lean muscle burns more calories than fat at rest, so increasing your lean muscle mass could help you lose weight.


  • CLA may help encourage weight loss by speeding up metabolism, helping the body to use stored fat and increasing insulin resistance, among many other things
  • When combined with a healthy diet and exercise, studies have reported exceptional results

CLA dosage

Health and diet experts recommend taking 1 to 3g of CLA a day. People who weigh 155Ibs or more should take 3.5g to receive its full health benefits.13

Can you take CLA every day?

Yes, it is possible to take CLA every day, but make sure you don’t exceed the recommended dosage and always follow the manufacturer’s guidance.

How much CLA do you need a day?

It depends on what you are taking it for. It’s also important you take it in accordance with advice from a medical professional. Generally speaking, doses typically range from 3 to 6g a day.14

When is best to take CLA?

The general consensus is that CLA is most effective when it’s taken before or during meals, which can help your body absorb it better.15

CLA side effects

The most common side effects linked to taking CLA are:

  • Stomach upset
  • Nausea
  • Diarrhea
  • Fatigue

Initial studies have suggested CLA may negatively impact blood sugar levels by hindering your body’s natural ability to handle insulin.

If you are diabetic, avoid taking CLA supplements unless you’ve been advised to do so by a medical professional.16


  • Between 1 and 3g of CLA per day is deemed as being a generally safe amount, but it’s important you don’t take CLA without speaking to your GP first
  • Taking it before or during meals can aid absorption

CLA reviews

Here’s what some of our customers are saying about CLA:

Wow - super-charged CLA fat-loss and improved skin - 5/5 stars ChLen88
“I swear by CLA for when I struggle to lose weight off my belly, bum and thighs. So I thought I would give these a try and I am super impressed! They are strong and definitely super charge fat loss when combined with weight training (for women).”

Great product - 5/5 stars Rossington bear
“Good fat burner. Noticed a difference after a couple of weeks.”

5 stars - 5/5 stars - - Vasia
“The concentration of CLA in this product and its reasonable price makes it the best CLA supplement. Also, the quality is great.”

CLA - 5/5 stars – Lizbiff
“I’ve bought 3 tubs of these as I’m so happy at how I feel taking them. I don’t feel bloated.”


CLA has been widely connected to weight loss, but a lot of the studies carried out so far show weight loss results may be minimal.

If you’re planning on trying CLA supplements, there are plenty of different options to choose from – powders, capsules, softgels and tablets - make sure you speak to a medical professional first before taking it.

For more insight on losing weight read this, ‘A guide to the best fat burners.’

The advice in this article is for information only and should not replace medical care. Please check with your GP or healthcare professional before trying any supplements, treatments or remedies. Food supplements must not be used as a substitute for a varied and balanced diet and a healthy lifestyle.

Last updated: 13 August 2021



Author: Donia HilalNutritionist

Joined Holland & Barrett: Jan 2018

Bsc in Nutrition, Registered Associate Nutritionist and Certification in Pre and Post Natal Nutrition

Donia started her career as a freelance nutritionist, later she joined Nestle as their Market Nutritionist to help support their healthier product range, before joining the team at Holland & Barrett in January 2018.

Donia has over 6 years experience as a Nutritionist and also works with clients on a one to one basis to support their goals which include weight loss, prenatal and postnatal nutrition and children’s health.

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