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Do CLA Weight Loss Supplements Work? Are They Safe?

CLA supplements have been touted as the miracle weight loss pill. Do they really work, and how safe are they? We look at the evidence behind the hype.

CLA safe and effective

CLA, or Conjugated Linoleic Acid, occurs naturally in meat and dairy products. If you eat any foods derived from grass-fed animals then you more than likely get a good chunk of it in your diet at the moment.

Why then, do people choose to supplement CLA? Bodybuilding circles are constantly rife with speculation about new “miracle” supplements, but can something present in every day diets be worth supplementing to the extreme?

Let’s take a quick look at what CLA does, how it can benefit you, and the side effects of supplementation.

What exactly does CLA do?

CLA’s benefits have been talked about quite a bit. It’s been touted as a miracle weight loss pill, a muslce strength-booster, and even as a prevention for breast cancer (though this is far from accepted [1]).

Most in the fitness world are interested in it for its weight loss properties, of course. Its effect on the basal metabolic rate of animals let people to adopt it long before any significant studies had been carried out humans [2].

Since then, there have been a few more comprehensive studies, with most seeming to conclude that long-term supplementation of CLA leads to a reduction in body-fat mass in healthy adults [3].

Is CLA dangerous?

CLA was categorized as “generally recognized as safe” (GRAS) in 2008 by the FDA [4]. It was big news at the time.

What about the side effects of CLA? The side effects of CLA supplements are typically stomach upset, nausea and fatigue when taken in extremely high doses. The kind of run-of-the-mill side effects that you can expect from taking ridiculous amounts of ANYTHING.

There are plenty of horror stories and scaremongering about its effects on sugar absorbtion or liver condition, but these claims aren’t backed up with any tangible evidence. It’s FDA approved, supplement it sensibly and you’ll be fine.

Is CLA good for weight loss?

CLA supplements for weight loss

The most common question asked about CLA are in regards to its weight loss properties (of course!). Does CLA really work for weight loss? Yes. Steady consumption of 4.2 grams per day of CLA over a 12 week period has been shown to reduce body fat [5].

Should you rely on CLA to lose weight? Absolutely not. While supplementing CLA is more than likely to give you a marginal benefit and help you lose a few pounds, it’s unlikely to produce the results you have in mind when you picture a miracle weight loss pill.

Combine CLA supplementation with a solid workout routine and you’re sure to reap the full benefits. As with any weight loss supplement, the dosage is what matters. Even supplements that are totally naturally occurring can lead to negative side effects if you aren’t sensible with the dosage. Those who’ve gone overboard on green tea extract for weight loss will happily attest to that (bleh!).

Should you supplement CLA?

While things can change an awful lot in 20 years, a study conducted in 1998 about the consumption of CLA through our diets saw that the estimated intake was around the 0.43g mark [6].

Seeing as that’s not even remotely close to the amounts found to make a difference in adult humans, the answer seems to be yes. Yes, you should supplement CLA if you expect to see any weight loss benefits from it.

Supplements like CLA are commonplace, and we’d recommend you pick up a pure CLA supplement rather than a blend of supplements in one pill. You’ll be more confident that you’re supplementing the correct dose that way. If you’re looking for a guide to buying, we’ve given our recommendations and written a handy guide on the best CLA to buy for weight loss.


Sensible dosages over a long period are likely to show results. Stick to your workout plan, eat healthily, and if you feel that the benefits are worth it, then supplement CLA to get a marginal boost.



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