You see on the shelves, in commercials, in websites online, and pretty much everywhere: fat burning supplements. And the promise is seductive: take the pill, and lose fat without exercise or changing your nutrition.

But there’s really 2 questions that arise:

  1. Are the claims true? Is it really effective? And if it is then…

  2. Is it safe? Or is there a price you pay for a “fat burning pill”?

That’s what we’ll cover in this article. However, rather than discussing each specific product, I’ll discuss ingredients. Products may come and go, but ingredients are much more stable.

Original source: here.

CLA (Conjugated Linoleic Acid)

Over the last few years, this one really gained popularity. Too bad it doesn’t really help with fat loss all that much.

In one study, obese participants had to take 1.7 grams of CLA per day to reduce their fat by 0.69 kg (or 1.5 pounds) in 12 weeks. Whoop-dee-doo.

In another study, obese participants took 3.4 grams of CLA per day to reduce their fat by 1.73 kg (or 3.8 lbs.) over a 12-week period.

In yet another study, overweight participants took 3.2 grams of CLA per day to reduce their fat by about 2.2 kg (about 4.8 lbs.) over a 6-month period. Again, nothing to write home about.

One other study noted absolutely no differences between taking CLA and not taking CLA.

As far as I’m aware, there’s no single study that found a large decrease in body fat as a result of taking CLA alone. And by “large decrease”, I mean something on par with the tried-tested-and-true diet and exercise. With the “gold standard” of just diet and exercise, fat loss is seen at a rate of 1-2 pounds per week.

Caffeine

You probably see a large variability in coffee drinkers – some are overweight, and others are quite lean. So intuitively, you should know that caffeine doesn’t make much of a difference. But hey, if your intuition was hijacked by clever marketing, I don’t blame you.

Let’s look at what the studies have to say on the effectiveness of caffeine as a fat loss aid.

First of all, most research on caffeine is not done looking at fat loss. Most research on caffeine looks at things like endurance, power output, etc. And in those cases, yes, it’s proven very effective.

Very little research actually exists on the effects of caffeine on body composition.

The only study that I am aware of that looked at the effects of caffeine on body composition in people (as opposed to rats or isolated cells in a laboratory) showed no effects when taken for 8 weeks, at a dose of 201 mg (the equivalent of about 2 small cups of coffee).

L-Carnitine

Carnitine is another newcomer on the scene of fat loss supplements. It’s been studied in the realm of heart and brain health for years, but only relatively recently has there been research on fat loss. And the research shows… ineffectiveness.

One of the very few studies on the effects of carnitine supplementation in humans showed that taking it for 8 weeks, at a dose of 2 grams/day had no effects on fat loss.

Green Tea Extract

Another relatively new “darling” of the fat loss supplement industry is green tea extract. But really, does it work?

The answer to that is “yes”, but as with other compounds mentioned in this article, the effect is very minor.

In one study, participants took 886 mg of green tea extract, and ended up losing 1.2 kg (or 2.5 lbs.) over a 90-day period.

One meta-analysis found that supplementation with green tea extract results in an average weight loss of 1.3 kg over the same, 90-day period. Nothing really exciting there.

Garcinia Cambogia

This one seems to have it all: exotic-sounding name, it comes from a plant, it appeared on the Dr. Oz Show. There’s just one problem… it doesn’t work.

In one study, when participants took 2 grams per day of garcinia cambogia for anywhere from 1-6 months, their weight changed by… nothing.

In another study, when participants took 3 grams per day of garcinia cambogia for 1-6 months, their weight also changed by… nothing.

L-Tyrosine

There’s a lot of stuff it does. It might improve cognition, and it might improve perceptions of stress, but as for weight loss… we don’t know.

To my knowledge, not a single study has been done examining the effect of tyrosine supplementation on weight loss in humans.

That doesn’t mean that it doesn’t work. It just means that we don’t know whether it works.

Cayenne Pepper

Just like tyrosine, there’s no research on whether supplementing with this works in humans. One single study looked at consumption of actual peppers (as opposed to supplementing with it in a pill form), and concluded that over 1-2 years of regular consumption, it may help with weight loss.

So now, we’ve looked at supplements that either don’t work at all, don’t work very well, or we don’t know whether they work. Which brings us to the question of: are there any supplements that work well?

And fortunately, the answer to that is “yes.” There are two that I’m aware of.

Ephedrine

Back in the 90s, ephedrine was wildly popular. It made you lose fat without changing your nutrition and exercise.

One study found a loss of 6.6% body fat over a 12-week period. The participants took 25 mg of ephedrine, with 200 mg of caffeine, 3 times per day. That amount of fat loss is comparable to or better than the gold standard of good nutrition plus exercise. And the participants in that study didn’t change their diet and exercise.

Another study found a loss of 4 kg (almost 9 pounds) over 8 weeks of supplementation with ephedrine and caffeine. They used 72 mg of ephedrine, and 240 mg of caffeine per day.

Not bad. However, what are the downsides to such effective fat loss? There are a few:

In some people (not everyone), ephedrine can cause:

  • High blood pressure

  • Insomnia

  • Nervousness/anxiety

  • Headache

  • Dizziness

Some of these effects go away after supplementing with it for a few weeks. And some people don’t experience any of these side effects, at all.

Keep in mind, there are no long-term studies (more than 6 months) on ephedrine. So whether it’s safe beyond that period of time is unknown.

Another little problem: it’s VERY hard to find in Canada. Because of a few people abusing ephedrine, and taking it in crazy high dosages, they died. And subsequently, it was banned, but on some occasions, you can still find it.

Yohimbine

Another effective supplement. Whether used orally or as a cream. One study showed that 20 mg of yohimbine taken for 21 days reduced body fat by 2.2%. Now that’s crazy good. That’s on part with, or maybe even a bit faster than standard diet and exercise.

One cool study even found that when yohimbine cream was used in women’s thighs, they compared the use of yohimbine in one thigh, to another thigh (where they rubbed a cream that wasn’t yohimbine, but thought that it was). The thigh that used yohimbine lost more fat than the thigh that didn’t.

The side effects from yohimbine include the same side effects as from ephedrine. But again, not everyone experiences those side effects, and for other people they’re are unbearable.

Oh, and one other thing… it’s also banned in Canada.

So then, if most so called “fat burning supplements” either aren’t effective at all, or mostly ineffective, why are they marketed as such? Is it all a complete lie, or is there even a shred of a reason behind them? There are a few reasons:

  1. Sometimes, research done in mice or rats shows that they lose body fat on certain ingredients. Too bad they aren’t humans.

  2. Some studies measure short-term (as in, hours) increases in fat metabolism. They then extrapolate to the long-term. But if the end result (fat loss) wasn’t studied, that extrapolation is incorrect. There may be short-term increases in fat metabolism, but beyond the first few hours after taking the supplement, fat metabolism may be suppressed, with the end result being equilibrium. No net gain or loss in fat. But if the long-term wasn’t studied, no conclusions can be made.

  3. In some studies, there’s a mechanism by which fat could be lost. That mechanism is plausible, but again, the end point of actual % or pounds of fat lost doesn’t exist.

  4. Some studies are done in petri dishes. They don’t study humans. They study an individual cell. A human is much more complex than that.

  5. Dosages matter. The studies showing effectiveness may use one dosage, whereas a supplement contains a much lower dosage than what’s proven to be clinically effective.

  6. Amount matters. It would be correct to say “this supplement was shown to help people lose fat.” The question really is “how much fat?” If the answer is “it helped people lose 3 pounds in 12 weeks” (which is often the case), it’s not really all that exciting.