Do Fat Burners Work? (The Science-Based Truth Revealed)

Lisa Lorraine Taylor, BSc, CPT
Published by Lisa Lorraine Taylor, BSc, CPT | Staff Writer
Last updated: June 19, 2024
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The fitness world evolves every day because people strive to keep fit.

Recently, fat burners have been introduced, which are perceived to help people shed some unwanted weight.

This has led to the question if the fat burners actually work or if they are just a scam.

Understand that fat burners trigger the metabolic reaction, which burns stored fat and is used as fuel for the body. The metabolic processes are thermogenesis and lipolysis.

Quick Summary

  • Fat burners work by triggering metabolic processes in the body that help the body source fuel from stored body fat, especially when combined with a disciplined fitness regimen.
  • Common ingredients in fat burners include natural substances like caffeine, green tea extract, and L-carnitine, known for their fat-burning properties.
  • L-carnitine in fat burners has a direct impact on your metabolism and its ability to process fat, according to the study published in PubMed.
  • In my opinion, while fat burners can be effective, they should be used responsibly and in conjunction with a healthy diet and exercise for the best results.

How Do Fat Burners Work?

Fat burners work by triggering metabolic processes in the body that help the body to source fuel from stored body fat and also inhibit fat absorption.

In my years as a personal trainer, I've seen how fat burners can effectively trigger metabolic processes, helping clients source fuel from stored body fat, especially when combined with a disciplined fitness regimen.

Tracing the history of fat burners reveals a fascinating evolution, from early herbal concoctions to today's scientifically formulated supplements, highlighting how consumer preferences and scientific advancements have shaped these products over the years.

Generally speaking, these metabolic processes can be split into 2 categories:


1. Thermogenesis

Two runners working on fat burners

Thermogenic fat burning processes involve burning calories to produce energy in the form of heat [1].

Your body does this even when resting to maintain constant body temperature.

Exercise also triggers this fat metabolism process, but you can further boost thermogenesis with fat burners.

As a result, you can achieve an increase in weight loss when it is combined with a healthy diet. Basically, thermogenesis can be maximized through a combination of net negative calorie intake, exercise, and supplements.

2. Lipolysis

Lipolysis is the body's process of breaking down fats into energy.

Supplements can enhance this by stimulating hormones like ghrelin, epinephrine, and norepinephrine, leading to increased fat loss.

However, it's crucial to understand that these supplements are not standalone solutions for significant weight loss.

Effective results require a combination of a balanced diet and consistent exercise.

Common Ingredients Found In Fat Burners

spoons and bowls of raw ingredients

While all dietary supplements for weight loss work with their own special blends of ingredients, there are certain nutritional sources that are quite common.

From my experience, the most effective fat burners often contain a blend of natural ingredients like caffeine and green tea extract, which I've seen provide tangible results for my clients.

The first ones I want to highlight are the foods you can take in a natural way.

1. Natural Food Sources

Fortunately, mother nature has provided quite a few sources that you can easily add to your diet plan.

Either follow the below steps or look for these elements in fat burning supplements.


cup of coffee being poured

Caffeine, commonly found in morning coffee, can aid in weight loss by creating a thermic effect.

Research indicates that small amounts of caffeine can increase energy expenditure by 16% over two hours.

However, it's important to note that the body adapts to caffeine over time, reducing this effect.

It’s a great stimulant to take before you head to the gym, but don’t overdo it. Also consider some caffeine-free fat burners if you get too jittery with caffeine.

Green Tea Extract

green tea extract with raw ingredients

Green tea extract is basically a concentrated form of green tea commonly found in homemade fat burners.

If you like this type of tea, then you can elevate your consumption, but the taste isn’t that appealing to many people.

It also helps to suppress your appetite that's why it is also a must have for night time fat burner.

Taking it in the form of pills or powder will give you a boost in caffeine and a polyphenol called epigallocatechin gallate.

Combined, these two amplify the fat burning outcome and increase thermogenesis at the same time.

Most supplements available today, especially vegan fat burners, contain green tea extract not just for fat reduction, but it’s also a powerful antioxidant, according to the study published in PubMed Central [2].

This makes it ideal for helping to flush out unwanted toxins at the same time.


raw turmeric that's turn to powder

Turmeric contains an antioxidant called curcumin, and this has been tested in several clinical studies to identify its usefulness in treating obesity. It works in two supporting ways.

First, it triggers thermogenic fat burning processes that essentially elevate your body temperature by burning more fuel, i.e., fat.

Secondly, it helps the gallbladder to produce more bile that makes the breaking down of dietary fat more efficient.

Adding this to your diet is actually quite simple, as you can add the spice to your main meal or take it in the form of a tea.


Cinnamon sticks grinded up

Cinnamon, more than just a flavorful spice, contains cinnamaldehyde, an essential oil with thermogenic properties.

This compound slightly raises body heat, aiding in the burning of body fat for energy.

One option is to add a teaspoon throughout the day to your green tea or snacks.


cloves of garlic

Yes, for most people the smell is going to be just too bad, but others love the taste it brings to meals.

It’s certainly something you want to moderate to avoid living in isolation, but garlic triggers very similar processes to cinnamon.

Weight loss can be increased with relatively small amounts of garlic extract, which has less of a bad smell to it when mixed into pills and powders [3].

Ideally, you should take this in raw form by adding some to your evening meal. This will have the added benefit of acting as one of the best appetite suppressants, so you avoid waking up starving.

Here's an interesting video from Chef Ricardo on how you can use garlic for weight loss.


roots from ginger

Ginger, an often overlooked natural ingredient, has shown positive effects on weight loss, particularly in obese individuals.

Incorporating ginger into your diet, either by steeping it in boiling water to create a tonic or adding it to smoothies, can enhance thermogenesis and aid in fat burning.

There is also some anecdotal evidence that combining all 3 on a daily basis amplifies the results.

Soluble Fiber

various bowls of grains with fiber

Fiber, a crucial but often under-consumed nutrient, plays a significant role in weight management.

While some view it negatively due to its carbohydrate content, its real benefit lies in aiding digestion and nutrient absorption.

Research indicates that soluble fiber can positively impact metabolic rates, thereby facilitating quicker weight loss.

Beans and green veggies are the best sources of fiber, but you can also buy it in powdered form to give your digestion a helping hand.


raw yohimbine

This is one of the well kept Western African secrets that has become increasingly more available in the USA.

While its intended use is an aphrodisiac, there has been one very interesting study that revealed its results on fat metabolism.

By giving soccer players small doses, researchers were able to note a 2.2% decrease in BMI, which is not insignificant, considering that these players would already be very fit.

This does make it a very interesting product to top athletes and bodybuilders with any cutting phases they are going through.

It isn’t something you’ll find in supermarkets, but if you check out a local whole or health food store, you’ll be able to pick some up quite easily.

"Dosages of 0.2mg/kg bodyweight have been successfully used to increase fat burning without significant implications on cardiovascular parameters like heart rate and blood pressure."
- Kamal Patel, Co-founder and Director of

Now let’s shift our attention to elements that are a bit more difficult to get through food.

2. Concentrated Supplements

The above natural ingredients are easy to add to your eating habit, but there are some things that can be a bit more difficult to get enough of.

This is mainly because they are usually only contained in small amounts, and you’d have to eat a lot of them to get any result.

That’s why these types of fat burning nutrition elements are best sourced through pills or powders where they are contained in concentrated form.


pill bottle of l-carnitine

L-carnitine in fat burners has a direct impact on your metabolism and its ability to process fat, according to the study published in PubMed [4].

The way it works is by helping to transport fatty acids to cells where they are converted into raw energy.

Basically, the more of this stuff you can take, the faster your body can process stored fat.

Many athletes like taking it as part of pre-workout shakes as it reduces the dependence on carbs for energy.

However, it’s also a great product to have on your list to help with a cutting phase or just to lose weight.

You’ll find a lot of pre and post workout products will contain it, so always look out for it on labels.

Conjugated Linoleic Acid

Conjugated-Linoleic-Acid for weight loss

Conjugated Linoleic Acid (CLA), a variant of Omega-6, is not naturally produced by the body. Initially valued for its antioxidant and immune benefits,

CLA has gained popularity for aiding in fat loss and muscle preservation. It's a common ingredient in bodybuilders' cutting stacks, favored for its minimal side effects.


Jar of l-tyrosine powder

An increasingly popular component in bodybuilding supplements, this ingredient boosts adrenaline and noradrenaline production.

This elevation in neurotransmitters slightly raises heart rate and body temperature, enhancing metabolic activity and fat oxidation, though not to the extent of causing an intense adrenaline rush.

When you add the fact that it helps to reduce appetite, you get a two-pronged approach by burning fat and reducing food intake.

Doesn’t get much better than that.


grapefruit cut up

Extracted from citrus fruit peels like lemons, oranges, and grapefruits, this substance is challenging to consume naturally due to the unpalatable nature of the peels.

However, a 2014 study showed that a daily intake of 900 mg significantly increased metabolism and reduced abdominal fat in overweight individuals.

While still relatively new in the market, it's worth checking for this ingredient on product labels.

With all these ingredients, you’re probably wondering how you’ll get the best results.

How Do You Get The Most Out Of Fat Burners?

As a personal trainer, I advise my clients that the key to maximizing the benefits of fat burners lies in combining them with a rigorous exercise routine and a well-balanced diet. If you follow this, then the answer to the question "Do Fat Burners Work?" is definitely - YES.

Understanding that the effectiveness of fat burners can vary greatly depending on individual factors like metabolism and lifestyle underscores the importance of a personalized approach to selecting and using these supplements.

I cannot stress too much how important your food is when it comes to getting to your fitness goals. But first, find out if you are a sugar burner or a fat burner type.

Did you ever increase fat around your waist despite going to the gym?

Chances are you got these results because your eating habit was still full of crap.

Fixing that is the first thing you need to do, and after that, you can focus on maximizing your fat oxidation through a couple of simple tips.

1. Minimize Cardio

A man running with a cross over him

Cardio is great for your heart and vascular system, but it simply won’t give you the best results.

For the weeks you are taking fat burners, you have to up your game and hit the gym hard, by increasing the weights and reducing the reps in your workouts.

And rather than going for a leisurely 30-minute run, alternate between 30-second sprints and jogs.

This will drain your carb reserves, and you will start burning fat more effectively when running.

This might surprise most people, but when you want to get rid of fat, then you have to increase your energy expenditure and burn more calories.

2. Don’t Rely On One Product

various fat burning products

The unfortunate thing is that your body will get used to the stimulating and metabolic impacts and simply start responding less to them.

That’s why I always recommend that people switch between the above-mentioned options on a regular basis.

It doesn’t have to be a daily change, but if you change things around every few weeks it will have a very positive outcome on your goals.

When you’re looking at supplementing your meals, it’s just as important to pick a couple of reliable products to do the same thing.

Related Article: Instant Knockout Fat Burner

3. Avoid High Doses Of Stimulants

stimulant pills spilled on a table

While caffeine will provide significant benefits in reducing your BMI, these types of stimulants compared to stimulant free options can cause some unwanted problems.

And many people don’t keep track of all the stimulants they take, which just adds to the problem.

If your pre-workout, fat burner, morning coffee and evening green tea aren’t added up correctly, then you could quickly find yourself with jitters and a real difficulty getting to sleep at night time.

The easiest way to avoid this is by keeping a food journal and adding it up on a regular basis.

Also Read: Which one is better? Leanbean or Instant Knockout?


4. Plan Regular Off Cycles

man sitting on a bench at the gym

Professional bodybuilders and athletes typically cycle their fat loss phases.

They engage in cutting phases for competitions, followed by periods of increasing body fat.

This approach is crucial as maintaining a minimum level of body fat is essential for a healthy immune and digestive system.

Even for those not in extreme fitness regimes, taking breaks from continuous fat loss is beneficial to prevent the body from becoming resistant to metabolic boosters.

5. Safe Weight Loss Goals

Unless you’re morbidly obese with imminent health risks, aiming for 2 to 3 pounds per week is more than enough.

I have seen it with many clients that went for higher rates, only to achieve worse results in the long-run. Constantly achieving lower goals is far more motivating and will help you adjust to lifestyle changes you’re making.

When it comes to reducing body fat, the general rule is that slow and steady brings the best results.

Fat Burner Side Effects

woman in bed with pillow over her head

If you stick to recommended doses that are printed on the labels, then negative side effects will generally be very limited.

In my professional experience, sticking to the recommended doses of fat burners minimizes side effects. However, I always monitor my clients for any adverse reactions and adjust their regimen accordingly.

In some cases, food allergies and intolerances are the underlying cause, and it may take some experimenting to find a suitable product.

Here are a few danger signs to look out for with fat burners, and if you notice any of these, then take a break immediately:

  • Nausea
  • Constipation
  • Headaches
  • Jitters
  • Insomnia

Many people tend to just pay attention to their weight loss while taking these types of products, but ignoring changes in your body can be more of a hindrance than you might think.

Not only will it reduce your motivation, but the way your digestive system and metabolism reacts can cause the exact opposite results you’re looking for.

"The most common complaints include nausea, constipation, abdominal pain, and headache. What’s more, these supplements may lead to a slight increase in blood pressure."
- Erica Julson, Registered Dietitian


various brands of different fat burners

Is It Safe to Take Fat Burners?

Yes, it is safe to take fat burners as long as you stick to the recommended dose. Most products are available as pills or powder with very clear guidance on how much to take. Stick to this, and you’ll be doing just fine.

What Is a Thermogenic Fat Burner?

A thermogenic fat burner causes your body to increase its body temperature by burning more calories. If you’re taking in a net negative amount of calories, this will mean that fat oxidation will target those stubborn flabby areas you want to get rid of.

Is Apple Cider Vinegar a Fat Burner?

Yes, apple cider vinegar is a proven fat burner and is often promoted by dieticians as an effective way to reduce belly fat. It’s also very easy to add a couple of tablespoons to your food every day [5].

When Should You Take Fat Burners?

Ideally, you should take fat burners several times a day to spread the action out for a maximum fat loss. Before your workout and HIIT sessions is also recommended, as this can really elevate your metabolic rate.

Does Coffee Burn Fat?

Yes, coffee helps to burn fat, or more precisely, the caffeine contained in it does. If you don’t like coffee, then green tea is another option that will help with fat loss. It’s less potent, but still a perfectly suitable option.

Will Fat Burners Burn Muscle?

Fat burners will not burn muscle, provided that they are used responsibly and as directed.

How Long Do Fat Burners Stay in Your System?

The duration that fat burners stay in your system can vary depending on the specific ingredients and formulation of the product. In general, most fat burners are designed to be metabolized and eliminated relatively quickly, typically within a few hours to a day.


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About The Author

Lisa Lorraine Taylor, BSc, CPT
Staff Writer
Lisa Lorraine Taylor, BSc, CPT holds a BSc degree in Holistic Nutrition from Clayton College of Natural Health and is the owner of Taylor Made Fitness. Her philosophy centers on cutting through the hype and misinformation surrounding dietary supplements, focusing instead on practical, science-backed strategies for health and weight loss.
Learn more about our editorial policy
Dr. Harshi Dhingra, MBBS, MD is a published peer-reviewed author and renowned physician from India with over a decade of experience. With her MBBS from Bharati Vidyapeeth and an MD from Rajiv Gandhi University, she actively ensures the accuracy of online dietary supplement and medical information by reviewing and fact-checking health publications.
Learn more about our editorial policy

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