4 Fat Burner Supplements that Raise Metabolic Rate

By Ali Kuoppala | Last reviewed Tue 25 September 2018

Medical Review by Gerardo Sison, PharmD

Fat burners are a huge market all around the world, and why wouldn’t they be? Most of the people on this planet at some point of their lives want to lose some weight.

For those people, there’s a market full of different fat burner supplements, all claiming to help with those stubborn pounds…

The awful truth is that most of the products on the market are just a complete waste of money with no real science backing up their effects, but as long as people keep buying them, the market will keep thriving and new BS-supplements and “revolutionary breakthroughs” will pop up day after day.

From raspberry ketones to Garcinia Cambogia and all the way to the snake oil supplements, people are getting ripped off daily by the clever marketing and hyped up pseudo docs such as the notorious tool, Dr. Oz.

After you follow the industry for a while with healthy skepticism, one obvious question raises its head.

What actually works?

1. Capsaicin

capsaicin as a fat burner supplementCapsaicin is an alkaloid that makes all chili peppers hot. Basically the higher the capsaicin content, the hotter the chili.

Capsaicin is also the reason why hot foods are often linked to increased fat loss. Just type in “fat burning foods” to Google and you’ll be surprised how many of those hot foods are actually presented in those fancy lists.

And that’s not a big surprise. Capsaicin has some really cool science backing up its fat melting effects.

Just take a look at these studies:

All-in-all, capsaicin is a pretty solid fat burner in terms of science.

And what makes it even better, is the fact that you can get it simply by using some cayenne pepper (or other hot chili peppers) in your diet, and if heat is a problem, there’s also plenty of capsaicin supplements on the market (affiliate link).

2. Caffeine

caffeine and coffee as fat reducing supplementsEveryone knows caffeine, it’s the compound in coffee that’s behind the energy you get from a cup.

But not only does caffeine make you more energetic, but it also has a fat burning effect, which is probably why some “fat burners” on the market have it.

The sheer amount of studies done on caffeine is staggering.

And here are some of the ones that are linked to the fat burner like effects:

  1. Caffeine has been shown to increase metabolic rate in humans.
  2. Caffeine ingestion increases thermogenesis in the body, dose-dependently. Meaning that more calories are burned.
  3. Caffeine also improves anaerobic performance and muscle endurance in humans, which indirectly improves your workouts, and therefore also fat oxidization.

I’ve been anti-caffeine previously as the substance tends to increases cortisol secretion, which can lead to lowered testosterone levels over time. However, I managed to find 2 very interesting studies about caffeine’s effect on male testosterone levels when taken pre-workout.

…Firstly, this study shows that pre-workout caffeine was able to actually increase serum testosterone levels in resistance trained males (cortisol also increased).

…Secondly, the researchers in this study gave their subjects some caffeinated chewing gum, their subjects saw increases in serum testosterone, and surprisingly also decreases in cortisol.

So maybe I have been too judgemental about caffeine before. Seems to be OK when taken pre-workout.

If you’re not a big fan of coffee, caffeine can also be supplemented with.

3. Synephrine

synephrine fat metabolismSynephrine can be found in bitter citrus fruits, such as the bitter orange for example.

It’s a naturally occurring chemical and structurally similar to catecholamines (adrenaline and noradrenaline) which are the compounds that cause the breakdown of fat cells.

Being similar to the catecholamines, synephrine also has similar effects in the body.

Here’s some research:

  • This study found out that a single dose of 50 mg synephrine was able to increase metabolic rate by 65 kcal in the following 75 minutes after ingestion in humans that were in a rested state. Even better, synephrine did this without altering blood pressure or cognitive abilities.
  • This study found out that synephrine increases the thermic effect of food, meaning that you can basically eat a bit more when taking it.
  • One study found out that synephrine and caffeine work synergistically with each other, and therefore can be stacked.
  • This study saw that synephrine is an antagonist to the receptors A1 and A2, which work by preventing fat mobilization.
  • The researchers in this study saw that synephrine increases lipolysis and metabolic rate.

All-in-all synephrine is a well documented fat burner. It can also be particularly useful against the mysterious “stubborn body fat” as that’s mainly caused by the high density of A1 and A2 receptors (in males these are located at lower belly and lower back, and in women they’re most dense in legs and ass), synephrine seems to block the activity of these receptors.

You can get some high-quality synephrine from Amazon (affiliate link).

4. Yohimbine

yohimbine fat lossYohimbine is one of the active ingredients in a herb by the name of Yohimbe bark. It’s most commonly used as an aphrodisiac, mainly because this study shows it to be somewhat of a natural erection booster.

It’s also sold as a testosterone booster despite the fact that human studies show how it doesn’t even budge the big T (it did increase penile girth in that study, however, which indicates that it should work as a natural aphrodisiac).

As for the fat burning effects, yohimbine works as an antagonist to the A1 and A2 receptors, and can, therefore, be particularly helpful against “stubborn body fat”. This human study actually found out that 21 days of yohimbine supplementation (2 doses of 20 mg daily) was able to reduce body fat levels from 9,3% to 7,1% when compared to placebo in elite soccer players.

The catch is that you need to take yohimbine and then exercise in a fasted state to get the benefits out of the herb, as insulin completely negates the fat burning effects.

Also, avoid megadosing with the substance, high doses can increase blood pressure, spike cortisol, and even cause anxiety and panic attacks in sensitive subjects.

If you’re not afraid of the possible side effects and like to workout in a fasted state (think intermittent fasting), then yohimbine supplementation might be particularly useful for you.


There you go. 4 scientifically proven fat burners that actually work in humans. No pseudo-bull-shit or half-assed studies done on retarded ducks.

Those four should be enough to make a drastic difference in your dieting efforts, provided that you’re actually watching what you eat and exercising…

…Because quite frankly, not a single fat burner will help you if you can’t control your eating habits or can’t get up from the couch.

Ali Kuoppala

Ali Kuoppala is the founder of Anabolic Men. He has authored and co-authored multiple men's health books and focuses on uncovering the methods of optimizing hormonal health. To date, his articles on various websites have been read more than 15-million times. To read more about Ali, visit his Medium article.