Best Fat Burners & Thermogenic Supplements for 2021 – Reviews & Buyer’s Guide


If you buy something through a link on this page, we may earn a small commission. See our disclosure page.

Gaining weight can be a tad too easy. I am sure you have heard people joke that they can gain weight just by thinking about food.

Losing weight, on the other hand, is not so easy. You may be working out, eating right, but you see minimal results or nothing at all.

Lack of consistency in our weight loss journey happens to almost all of us. At other times you may be getting good results for a short period, then you reach a plateau where nothing is happening.

If you are continuously frustrated between flabby and toned or just want to lose some pounds, fat burners, the new aid for losing weight and gaining muscles, are the perfect solution for you.

In this guide, we reviewed some of the best fat burner supplements that may be best for your fitness goals. However, before we delve deeper, let’s first understand what fat burners really are;

What is a fat burner?

You’ve probably heard of a magic pill. When you take it, you just wait, and all that excess weight melts off you.

How do we tell you this?… It’s a lie!

The pill doesn’t exist; at least, that is not what a fat burner is.

So what exactly is a fat burner, and how does it work?

Fat burners are, simply put, health supplements that help the body eliminate fat by focusing the metabolism on fat burning.

They work in conjunction with a healthy diet and regular exercise.

Most companies that market their supplements are magic pills, usually put in some serious chemicals. You may get results for a short period but will later begin to suffer side effects.

Steroids are some of the chemicals that they put in these supplements.

There are a few different types of fat burners with different functions. But we will look at those a little later.

Best fat burner supplements currently on the market for 2021

With the overwhelming number of fat burners in the market, it is easy to get confused. As you may already know, different supplements work differently for different people.

We have come up with a list of supplements that we believe are your best bet.

When making our list, we looked at:

  • The safety of the products
  • The reputation of the manufacturer
  • The effectiveness of the ingredients
  • Who it caters for
  • The online reviews of the product

Here’s what we came up with.

Instant Knockout 

Instant Knockout - Best Fat Burner Supps

Quality ingredients.
Free worldwide delivery.
90-day returns policy.
Scientificly backed.
No monthly commitment.
Reputable company.
Re-evaluated every year.

Not suitable for vegans
No discounts or deals
Only sold at the website

We feel this is the best overall fat burner in the market at the moment. The manufacturers of the brand call themselves Roar Ambition. The supplement has reviews from renowned MMA fighters and other celebrities.

Roar Ambition promises that Instant Knockout will do the following for you:

  • Give you the potential to burn as much fat like the professionals
  • Not give you a dosage problem. Easy to use.
  • Empower you to get rid of the excess fat that never goes away with other methods.
  • Ensure your safety as it is made from all-natural, safe ingredients.


Amount per serving:

  • Vitamin B6 – 5mg
  • Vitamin B12 – 10mcg
  • Zinc – 10mg
  • Chromium – 100mcg
  • Green Tea Extract – 500mg
  • Green Coffee Bean Extract – 100mg
  • Cayenne Powder – 100mg
  • Glucomannan – 1800mg
  • Caffeine Anhydrous – 300mg
  • Black Pepper Extract – 10mg

We can see glucomannan, which helps with appetite suppression. They went all-in with the energy boost having Green Tea Extract, Green Coffee Bean, and Caffeine Anhydrous all at once.

To make sure you don’t have an energy crash after all the caffeine, they added Vitamin B12 and B6. They both get rid of fatigue and tiredness and keep you working towards your goals.

Chromium and zinc help out with macronutrient metabolism. And chromium further aids in the regulation of your blood sugar levels.

How to take it 

You only take one capsule four times a day. For the best results, ensure you take all the pills at regular intervals.

Here’s an example:

  • First capsule – 8.00 am
  • Second Capsule – 11.00 am
  • Third capsule – 2.00 pm
  • Fourth capsule – 5.00 pm

Here you’ll be taking the pills 3 hours apart. You will also be taking the last capsule early enough that it will not interfere with your sleep.


The reviewers of Instant Knockout online are always raving about it. Initially, it was supposed to help MMA fighters and professional athletes before a fight.

However, men from all walks of life are enjoying it and celebrating the results it gives. But it only has one secret; you need to exercise and follow a healthy diet.

We only have one disclaimer, since it has so much caffeine, it would be advisable not to take it too close to your bedtime to avoid insomnia.

To learn more about it, read our Instant Knockout review.

For more information on the product, you can visit the Roar Ambition website or visit the Instant Knockout website using the link below:

<strong>Shop </strong><strong>Instant Knockout Now</strong>


*Individual results may vary. Please speak with a doctor or physician before undertaking a new weight reduction, supplement, or exercise regime.


leanbean fat burner

Vegetarian and vegan-friendly
Contains only natural ingredients
Is geared towards working for women
90-day money-back guarantee
Worldwide shipment
Great testimonials
Can only be purchased on the maker’s website
Premium product

For a long time, the only supplements on the market have been geared towards men. The women had to contend with severe side effects of stimulant-packed supplements too strong for them.

Enter Leanbean, one of the few supplements that are strictly for women. It has a combination of ingredients that work for women than any other supplement on the market.

We are picking it as our best female fat burner because the company had gone out of its way. They are constantly researching and updating the supplement.

The ingredients in the most recent formula are making us very happy.

Glucomannan is the product’s flagship ingredient, and the supplement is mainly geared towards appetite suppression.

The makers claim that it does the following:

  • Improve digestion
  • Promote fat metabolism
  • Regulate blood sugar levels
  • Increase your energy levels to help you work harder and longer

So what’s in it?


Amount per serving

  • Glucomannan – 3000mg
  • Green Coffee Bean Extract – 50mg
  • Vitamin B6 – 1.7mg
  • Vitamin B12 – 2.4mcg
  • Chromium – 35mcg
  • Choline – 82.5mg
  • Turmeric – 50mg
  • Garcinia Cambogia Fruit Extract – 100mg
  • Acai Berry – 20mg
  • Potassium – 10mg
  • Zinc – 11mg

As you can see, the latest Leanbean formula has lots of ingredients. We are only going to go through the most significant ones.

Glucomannan, as we have earlier said, is the one responsible for appetite suppression. It comes from the Konjac root fiber.

It works by swelling in the stomach when you take enough water. You then end up feeling full most of the time and eating less as a result.

Vitamin B6 and B12 help with kicking out fatigue and tiredness. Acai berry is a newcomer but has numerous benefits, including boosting brain function and managing cholesterol levels.

How to take it

You are only supposed to take six pills of Leanbean per day. And we advise that you take them with at least 250ml of water.

Because the supplement’s main function is appetite suppression, you should always take it before a meal or a snack.

Here’s a guide:

  • One pill 30 minutes before breakfast
  • One pill before lunch
  • One pill before an afternoon snack
  • One pill before your evening meal


Despite all the good things other reviewers and we have to say about Leanbean, it will only work if you eat properly and exercise.

Its price starts at $59 per bottle, but it gets cheaper when you buy more than one bottle. You can also save with the free shipping offer when you buy two or more bottles.

To learn more about this great product, read our Leanbean review.

If we have not convinced you enough and you need to find out on your own, visit the link below:

<strong>Shop Leanbean Now</strong>


*Individual results may vary. Please speak with a doctor or physician before undertaking a new weight reduction, supplement, or exercise regime.

Hunter Burn 

Hunter Burn - Best Fat Burner Supplement

Potent ingredients.
A reputable manufacturer.
Optimum dosage
FREE delivery to US for multi-buys
Made in FDA approved facility
Money-back guarantee

Premium product.
Can only be purchased at the maker’ website.

Hunter Burn is another Roar Ambition product. The company has been in the supplement market for quite a while and has a good reputation so far.

This product is mostly geared towards men. It is our pick for the best premium supplement because it has large doses for a male supplement.

According to Hunter Burn creators, when you start using it, you can only expect good things. Here’s a sneak peek:

  • It has a unique blend of ingredients to reduce your cravings and keep you trim
  • It is so easy to use and can easily fit into your busy lifestyle
  • You will suffer no side-effects
  • You can fight weight loss associated with aging and win


Amount per serving

  • Vitamin D3 – 3000lU
  • White Kidney Bean Extract – 500mg
  • Matcha Green Tea – 200mg
  • Glucomannan – 3000mg
  • L-Theanine – 200mg
  • Cayenne Pepper – 125mg

Hunter Burn is one of the few supplements that contain enough glucomannan to be effective. This is why taking a huge glass of water is vital.

There is no pure caffeine in this supplement, which may be surprising. But we still have cayenne pepper and matcha green tea to help with increasing your metabolism.

L-theanine and vitamin D3 are also here for energy. You can go hard on your workouts and still have the energy for your other daily activities.

Read the full breakdown of Hunter’s scientifically-proven ingredients here.

How to take it

You are supposed to take six capsules every day. There are 180 capsules per bottle, which will take you through 30 days.

You should take 2 pills before your meals three times and take and also increase your water intake.


Many supplements in the market claim results but have little to show for it. Hunter burn is a bit different.

First off, it has high-quality ingredients in very generous doses. The only drawback to it is the high price, but that is the trade-off for good quality.

The price for Hunter Burn starts at $75 per bottle. However, when you buy larger quantities, you get discounts and free shipping in the US and the UK.

If you want more information about this supplement, then read our Hunter Burn review.

We feel that this is one of the best premium supplements on the market. Visit the link below to order now.

<strong>Shop Hunter Burn Now</strong>


*Individual results may vary. Please speak with a doctor or physician before undertaking a new weight reduction, supplement, or exercise regime.

Hourglass Fit 

Hourglass Fit - Best Fat Burner Supps

No added stimulants (besides Guarana)
High-quality premium ingredients
Low risk of side effects
90-day satisfaction guarantee
All-natural formulation
Realistic, honest advertising
You can only purchase it on the official website
Contains gelatine (not vegan or vegetarian friendly)

As the name suggests, this fat burner is designed to give you an hourglass figure. It has been designed for women, but men can also use it and get results.

But the men may be out off by the feminine and bright packaging.

Roar Ambition, the company behind the supplement, promises you that when you start using it, you should expect the following benefits:

  • Increased metabolism and faster fat burning leading to a better trim shape
  • An energy boost that will enable you to work out more and continue with your day-to-day activities.
  • You’ll beat the cravings. You will always feel full and will not keep eating unhealthy food that makes you gain weight.

Hourglass also has a formula that works with your body and your hormones. Some may even call it a smart fat burner.


Amount per serving

  • Green Tea Extract – 500mg
  • Vitamin B6 – 4mg
  • Vitamin B12 – 10mcg
  • Vitamin D3 – 1000lU
  • Black Pepper Extract – 5mg
  • Cayenne Pepper Extract – 100mg
  • Glucomannan – 1500mg
  • Chromium – 125mcg
  • Guarana – 100mg

The blend of ingredients in this supplement is impressive for a fairly new women’s fat burner supplement. Green tea and cayenne pepper, for instance, have thermogenic benefits that boost your metabolism.

The vitamins B6 and B12 ensure you are not drained after the intensive exercises; you fall off the wagon.

There seems to be a running glucomannan theme on this list, but we are not complaining. I mean, the biggest hindrance to losing weight is being unable to stop eating.

Guarana is an interesting addition. It has immense benefits, including antioxidant properties that protect the body from the negative effects of free radicals.

Guarana also has some caffeine that boosts your metabolism that can help you lose weight faster.

How to take it

This has to be the easiest supplement to take on this list. All you need to do is take it one capsule three times a day.

Of course, you have to follow a healthy diet and keep being physically active for the best results.


We would have really loved to see more information on the hourglass website, but they seem to be the kind of people that want their customers to speak for them.

There are many reviews of happy customers online and no reports of severe side effects. Those are some of the reasons the supplement made it on this list.

We are also happy with the ingredients it has to offer.

Hourglass is also one of the cheapest supplements on this list, with a start price of $55. But it has great deals if you buy in bulk.

If you want more information about this supplement, then read our Hourglass Fit review or visit the link below:

<strong>Shop Hourglass Fit Now</strong>


*Individual results may vary. Please speak with a doctor or physician before undertaking a new weight reduction, supplement, or exercise regime.

Transparent Labs Physique Series 

Great value, comparatively.
Worldwide shipping.
Scientifically-proven, natural ingredients.
Reputable company.
Great testimonials.

Missing some key ingredients.
You can only order it on their website.

Transparent Labs is famous for coming up with different series of supplements to help with different body goals.

As the name suggests, this one is supposed to help you get the overall physique you want.

It is supposed to aid you with:

  • Researches science-based weight loss
  • Clean energy and focus
  • Reducing your cravings for unhealthy food
  • Increasing your basal metabolic rate, i.e., thermogenesis


Amount per serving

  • Forslean (10%) – 500mg
  • Green Tea – 400mg
  • 5-HTP – 300mg
  • L-Tyrosine – 300mg
  • L-Theanine – 240mg
  • Caffeine Anhydrous – 240mg
  • Cayenne Pepper Extract – 100mg
  • Synephrine HCL – 50mg

Forslean comes from the Coleus forskohlii plant that is native to areas with warm subtropical temperatures. Forslean is a product of the Sami/Sabina group.

We are also seeing 5-HTP for the first time on the list. It is an amino acid, which is part of creating serotonin. But it also helps in curbing hunger and cravings.

How to take it

All you need to do is take two capsules twice a day with about 9 ounces of water 30 minutes to an hour before a meal.

To ensure you don’t shock your body, you should start with one capsule twice daily and see how your body behaves.

You can increase the dosage after 3 days if there are no issues.


Transparent Labs PhysiqueSeries is very popular. This is mostly because the company has made a name for itself in the supplement business.

The customers also have amazing things to say about the product. The best part about it is that it is the cheapest on this list.

You can get a bottle starting from $49. You may also talk to them about paying 4 interest-free installments, which is a rare offer.

If you prefer a non-caffeinated product, Transparent Labs also has the stim-free version.

The only bone we have to pick with the manufacturers is the ingredients. It would be far more potent if we saw more of our favorite ingredients like Vitamins, B6 and B12.

We may also have been glad to see glucomannan or Konjac fiber.

Visit their website to learn more and even order if you are impressed. Visit the link below:

<strong>Shop PhysiqueSeries Fat Burner Now</strong>


*Individual results may vary. Please speak with a doctor or physician before undertaking a new weight reduction, supplement, or exercise regime.


How do fat burners work?

Different fat burners do different things. Although nowadays some of them can serve several purposes.

Let’s look at a few types of fat burners and their processes.

1. Thermogenic fat burners

Thermogenic fat burners increase your metabolism by increasing your body’s temperature. As the body is trying to regulate the temperature, it uses excess calories, and you end up shedding weight.

2. Carb blockers

These start our being good but may cause you to harm in the end. They work by inhibiting the absorption of certain carbohydrates.

They can also work on some of the enzymes that digest carbs and deactivate them.

3. Appetite suppressants

We have been talking about these a lot. A good example is glucomannan. They work by limiting your cravings.

When you eat less, you gain less calories.

4. Cortisol blockers

Cortisol is also known as the stress hormone and mostly comes with inflammation. Cortisol blocker limits the hormone production and stops it from wreaking havoc on your weight loss journey.

5. Thyroid regulators

The thyroid is a gland found in the neck and is associated with hormones. When it does not function properly, it may lead to hormonal imbalance.

The hormonal imbalance can lead to the slowing down of metabolic processes. Thyroid regulating fat burners work to improve the body’s metabolism.

Fat burner side effects

When making this list, we tried our best to ensure you had the safest supplements. However, like we keep saying, our bodies are different, and some people will experience fat burners’ rough side.

Some of the reasons that you may experience side effects when taking supplements include;

  • That you are over-enthusiastic and you overdose
  • You are allergic to some ingredients
  • The quantities of some ingredients are in excess. For instance, if you take a supplement with too much caffeine, you may experience jitters and energy crashes.
  • Your body needs some time to get used to the supplement. For example, some people notice their urine turning a different color.

However, as they continue to use the supplement for a longer period, it goes back to its usual color. If this happens, it is possibly because you are detoxing.

  • Using two or more potent supplements at the same time. They may have ingredients that react badly with each other, or your body may not be able to handle both.
  • You are taking these fat burners while on medication. If you have been here for a while, you’ve seen this a lot.

But I insist; if you are on any medication, do not start taking any fat burner before your physician gives you the go-ahead.

  • You have an underlying condition. Whether or not you are receiving medication for an underlying condition, it is vital to talk to your doctor before taking any supplements.

Having said all that, there are still some common symptoms that you should look out for. Should you experience one or several of them, you should reduce your dosage.

Should the symptoms continue after you reduce dosage, it would be best to stop taking the supplement altogether.

Let’s check out the symptoms.

  • Heart palpitations
  • Increased alertness
  • Insomnia
  • Headaches
  • Stomach discomfort
  • Fast and irregular heartbeats
  • Hyperactivity

Best fat burner ingredients

One of the most critical factors to look for when buying a fat burner is the ingredient. You need them to be safe and effective.

We feel that you should try and stay away from supplements that have a proprietary blend. Not all of them are bad, but why don’t they want us to know what we are consuming?

Here are some of the ingredients you should look for:

  • Caffeine

Since fat burners require you to be doing some form of exercise to get results, energy is important. Some supplements will use it as just caffeine, and others will call it caffeine anhydrous.

Caffeine anhydrous is a concentrated form of caffeine. Some researchers claim it is more potent, and others dispute the claim, so we’ll just assume they are the same.

The only downside to caffeine is that too much of it can cause side effects.

So if you see it in a supplement, it would be best to quit taking other substances with stimulants like coffee while taking the supplement.

  • Glucomannan

This is a product of the Konjac root fiber. It is a soluble fiber that ensures your appetite goes down.

When taking any supplement with soluble fiber, you must take plenty of water to get the best results.

  • Green Tea Extract

To lose weight, you need to use up more calories than you consume. Green tea can aid with that.

It keeps your body temperature high, enabling you to burn more calories during the day, even when you aren’t too active.

Enough of this supplement can hasten your weight loss journey. But it works even better when you work out.

  • Garcinia Cambogia

This is a small fruit shaped like a pumpkin. Its peel contains hydroxycitric acid as an active ingredient.

It works by reducing fat production, suppressing your appetite, regulating blood sugar levels, and reducing inflammation.

  • Turmeric

This is an anti-inflammatory that has been used since ancient times. Inflammation makes it difficult for the body to undertake its activities optimally.

Obesity comes with a lot of inflammation, but turmeric can help curb it. This is why almost all fat burners have it as an ingredient.

  • Cayenne pepper

This can be termed as a superfood. It has numerous weight loss benefits, including;

  • Boosting your metabolism
  • Aiding digestive health
  • Reducing hunger pangs

You will find the fat burners that contain cayenne pepper are very effective.

  • Bioperine (Black pepper extract)

When you take a fat burner, it needs to be absorbed into the body to work. Bioperine is the active ingredient in black pepper and enables the absorption of nutrients into the body.

Who should buy fat burner supplements?

Who should buy fat burner supplements?

Fat burners are primarily sold as agents of weight loss. If you use them alongside a proper diet and some exercise, you are bound to get results on that front.

But that’s not all; you can also use them as appetite suppressants in your daily life.

Whether you are trying to maintain your weight or you are simply trying to live healthier.

Professional athletes can also use it to lose those extra pounds and help them gain muscle.

If you are an avid gym-goer, fat burners could also help. Most of them contain energy-boosting ingredients that can help you work out harder for longer.

What to look out for (and avoid)

The market for supplements is growing by the day. There are always going to be dubious people taking advantage of people for a payday.

But not to worry, there are ways you can tell the genuine supplement manufacturers and the dubious ones.

Here’s how.

Are they selling a magic pill?

A real supplement seller that wants the best for you will give you a realistic view of their product.

If they are selling you unrealistic dreams that seem too good to be true, they probably are.

Always look for a fat burner that will encourage you to follow a healthy lifestyle.

Stay away from proprietary blends

As you have seen from our list, all the fat burners have listed ingredients and their quantities.

But some manufacturers will simply write “contains a proprietary blend.”

These are dangerous. If you are selling me something good for my health, why don’t you want me to know what you have used?

Do they keep changing brand ambassadors?

Some companies had been working with certain celebrities but suddenly stopped without an explanation.

Others are always involved in scandals that are also something to look into before buying a supplement.

Our verdict

Contrary to popular opinion, genuine fat burners are not and will never be a magic pill. There are so many of them in the market; it may be difficult to know who is right.

One of the most important things to do before taking a supplement is doing your own research. You can find reviews online and see what the majority of people are thinking.

You should also lookout for the ingredients and their quantities. It is also important to check out the reputation of the company.

We value our readers, and we are always looking for ways to make your experience with supplements worthwhile.

We sat down, researched, and came up with this list of the best fat burners. After analyzing all of them, we concluded.

Instant Knockout took the day. We feel it is the best fat burner supplement overall. It has customers raving about it and seems to have the most effective ingredients.

Our pick for best female fat burner is Leanbean. We love how its manufacturers keep updating it and adding more ingredients. We believe that Leanbean will be even better.

As far as price goes, Hunter Burn, hands down, beats other products on our list easily. However, we believe it is one of the best premium fat burners in the market right now. We love how large the doses are in Hunter Burn and also that they are of high quality.

As we sign off, we would like to remind you that fat burners are just supplements. And all they do is supplement your exercises and proper eating habits.

Do not let anyone lie to you otherwise and jeopardize your health in the process. We have made our list, but it’s now up to you to decide what you feel will work for you.

We wish you the absolute best in your weight loss journey!



Best Barbell Collars for CrossFit – Reviews & Buyer’s Guide [Updated 2021]

Best Creatine Supplements for 2021 – Reviews & Buyer’s Guide