Are Fat Burners Safe?

Are Fat Burners Safe?

Are fat burners safe and will they support your fat loss goals effectively?

You’ve made the decision to get on track and lose that excess fat that’s been clinging to your waist for some time now.

You’re motivated and raring to go. The diet is looking cleaner and your exercise program is beginning to take shape as you dust off your gym gear and hit the gym floor more regularly.

But with progress slower than you anticipated there are some question that keep crossing your mind…

Are fat burner supplements safe? Will they work for you? Which nutrients are best?

In this article we break down everything you need to know and take an honest look at the evidence

What Are Fat Burner Supplements?

Fat burners are specially-designed supplements with one goal in mind – to maximize the amount of fat you burn.

They are designed to be taken in combination with exercise and a healthy diet. As such, they aren’t miracle cures -but they are an effective weight loss aid when used correctly.

Fat burners provide you with a much needed boost when you want to kick start a new fat loss program or you’ve hit a plateau after losing weight already.

As an athlete, they are a great way to make weight for an upcoming fight or event.

Which supplements are classed as fat burners?

The term fat burner is a collective description for any supplement that aims to improve your fat mass to fat free ratio. It also includes any supplement designed to reduce your appetite or inhibit absorption of nutrients too.

They are typically made up of herbs, vitamins, minerals, herbs or extracts in differing quantities.

Different Types of Fat Burners

There are several types of fat burner supplements on the market.

In order to answer he question ‘are fat burners safe?’ you need to understand the different mechanisms behind how they work.

Here are the most common types of fat burners out there.

Thermogenic fat burners

Fat loss is all about calories in versus calories out. If your energy intake is less than what you burn off each day, you’ll begin to tap into stored fat.

But if you take on more than your body needs you’ll store the excess as fat.

Thermogenics help you boost the amount of calories you burn by increasing your metabolic rate. When consumed, thermogenic nutrients increase your core body temperature, leading to increased energy expenditure.

They are a safe way of getting your body to shift towards a calorie deficit.

Common thermogenic fat burners include green tea and cayenne pepper.

Do thermogenic fat burners work?


There are a number of studies that show thermogenic fat burners are safe – and work too.

For example, one study found that taking a commercially available thermogenic fat burner led to a significant increase in energy expenditure [1].

Green tea is the most researched and reliable thermogenic fat burner. Even high quality, robust clinical trials have found that it is safe to use.

The most comprehensive analysis of green tea supplementation was published in the Journal of Obesity [2]. Not only did was the nutrient found to be safe in all 49 individual studies included in the review; it was also found to significantly decrease body weight too.

Capsaicin, the bioactive compound found in cayenne pepper, is also a potent thermogenic.

This spice has it been found to increase fat oxidation and energy expenditure, with one review showeing that when in a calorie deficit, capsaicin fat burner supplements increased fat burning for up to 24-hours [3].

  • Are thermogenic fat burners safe?

Yes. They are not only safe but effective too. Nutrients such as green tea and spicy pepper can increase both your energy expenditure and fat oxidation.

Appetite suppressant fat burners

When it comes to putting the brakes on your fat loss, nothing has a bigger effect than overeating.

You’ll find appetite suppresant supplements either on their own, or combined with thermogenics for an added fat burning boost.

While thermogenics work by increasing your metabolic rate, appetite suppressants reduce hunger hormones such as ghrelin.

They help to keep you fuller for longer too.

Appetite suppresant nutrients include saffron extract, grapefruit and piperine. But when it comes to the safest most effective, glucomannanis your best bet.

As a natural fiber found in the root of the konjac plant, glucommanan has been found to safely reduce appetite in the most robust of studies.

A study published in Metabolism [4] found that combining the extract with a normal diet and exercise program led to both muscle mass gains and fat loss – by a massive 63%.

  • Are appetite suppresant fat burners safe?

Yes. Reducing your appetite with safe and natural supplements can be key to winning the weight loss war.

Carb and fat blocker fat burners

These kind of fat burners were once upon a time a go-to prescription drug – particularly fat blockers.

The medical industry very quickly realised though that they can lead to malabsorbtion of nutrients and were quickly taken out of mainstream medicine.

Nutrients such as cinnamon and white kidney bean are still available in some fat burners.

They are said to work by directly inhibiting absorption of either carbohydrate or fat from food.

When you eat, a number of mechanical and enzymatic reactions take place. For example, amylase in saliva helps to break down carbs in the food in your mouth, making it easier to absorb when it hits your gut.

Nutrients such as white kidney bean contain phaseolamin – a compound that stops your body absorbing carbs by shutting down enzymes such as amylase. The same thing happens with fat blocking by targeting enzymes called lipase inhibitors.

Are carb and fat blockers effective?

As a prescription medicine, blockers were very effective for weight loss. However, they were used mostly by morbidly obese patients and were likely to cause nutrient deficiencies when used long-term.

This is the main reason they aren’t used as much nowadays.

Nutrients such as white kidney bean aren’t as effective according to clinical trials. While they promise fast fat loss, they are more likely to leave you disappointed.

Many of the studies looking at white kidney bean as an effective and safe fat burner are confounded with other supplement ingredients. It hasn’t really been trialled on its own [5].

  • Are carb and fat blocker fat burners safe?

They are thought to be safe in the short-term, but not well tolerated by most people. When used over a period of time they can lead to nutrient deficiencies.

Chances are they won’t help you burn fat though as they tend to be under-dosed.

Are Fat Burners Safe to Use?

The short answer is that it all depends on the ingredients and doses.

Fat burners aren’t designed to replace a good diet or exercise, but when combined with an active lifestyle do help to accelerate your results.

If you’re training hard, eating right and not losing fat as quick as you’d hope, fat burner supplements are a safe bet to speed up fat loss. If you’re an athlete who needs to make weight, or even someone who needs to look their best for a holiday, wedding or school reunion then give them a try.

Thermogenic and appetite suppresant nutrients seem to provide better results in clinical trials, whereas carb and fat blockers may cause side effects.

The best way to to keep safe when using fat burner supplements is to do your research and go for high quality ingredients like green tea, cayenne pepper and glucomannan.

Not only that, but make sure you stick to the recommended dosage too.


  1. Hoffman, JR et al. Thermogenic effect of an acute ingestion of a weight loss supplement. Journal of the International Society of Sports Nutrition. 2009; 6:1
  2. Hursel R et al. The effects of green tea on weight loss and weight maintenance: a meta-analysis. Int J Obes. 2009;33:956–61
  3. Pilou, LH et al. Acute Effects of Capsaicin on Energy Expenditure and Fat Oxidation in Negative Energy Balance. PLoS One. 2013; 8(7): e67786
  4. Kraemer, WJ et al. Effect of adding exercise to a diet containing glucomannan. Metabolism – Clinical and Experimental. 2007; 56 (8): 1149-1158
  5. Celleno, L et al. A Dietary Supplement Containing Standardized Phaseolus vulgaris Extract Influences Body Composition of Overweight Men and Women. Int J Med Sci 2007; 4(1): 45-52