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Top 5 Best Fat Burners for Weight Loss
[Updated 2024]


Fat Burners Reviewed


Hours of Research


Reviews Examined


Experts Interviewed

A Lean Life Owner & Founder

Published by David Williams

As an engineer, David loves technical product comparison and analyzing the data to assess top products.

Table of Contents

What’s the best fat burner on the market in 2024? Well, we’ve taken a deep dive on this one and are ready to present the data! Here is our guide to the best fat burners on the market today. Let’s jump in!

Excess body fat comes with a host of health issues, including blood pressure, diabetes, cardiovascular disease, and more. But getting rid of it is not easy, especially with your busy lifestyle. If it were, so many people wouldn’t struggle with their weight.

Of course, good old-fashioned nutrition and regular exercise can help you eliminate some of that extra fat. But even that takes time and lots of dedication, which you might not have. That’s why fat burners are here to help you out.

Fat burners are weight-loss aids formulated to help you burn fat faster. They are not magic pills, but the best fat burners feature quality ingredients that can speed up your weight loss journey safely and effectively.

Read our detailed review of the top five best fat burners to help you eliminate that excess body fat and reach your fitness goals:

The Best Thermogenic Fat Burner Supplements - Instant Knockout Cut

Instant Knockout

Ingredient Quality

Appetite Control



Overall Score

The Best Thermogenic Fat Burner Supplements - Hourglass Fit

Hourglass Fit

Ingredient Quality

Appetite Control



Overall Score

Hunter Burn - Best Fat Burner

Hunter Burn

Ingredient Quality

Appetite Control



Overall Score


1. Instant Knockout Cut (Overall Best Thermogenic Fat Burner)

Instant Knockout Cut - Best Fat BurnerInstant Knockout Cut speeds up your metabolism through thermogenesis. This process burns calories to produce heat, creating a negative energy balance that leads to fat burning.

The diet fights even the most stubborn fat deposits, especially around your belly. In fact, it was initially designed for MMA fighters and professional boxers to help them shed extra fat. However, you can still benefit from its potent fat-burning effects even if you’re not an athlete.

The formula features a potent blend of natural thermogenic ingredients. They include black pepper extract, cayenne pepper seeds, and green tea extract. They are then supported by vitamin b6, l-theanine, glucomannan, and more.

Besides the thermogenic effect, Instant Knockout Cut provides an extra energy boost. Unlike other supplements, this one will not give you gas or a bloated stomach. It supports digestion and gut health, allowing you to enjoy the fat-burning benefits without discomfort.

Brand Overview

Best Fat Burners that WorkInstant Knockout Cut is a product of Roar Ambition. While this parent company has been in existence since 2012, Instant Knockout launched in 2014. Since then, the supplement has become one of the most sought-after fat-burning supplements.

Roar Ambition is a UK-based company at the forefront of sports and health nutrition. The brand owns some of the best and most popular supplements, all thanks to its team of nutritionists, scientists, and fitness experts. All its formulas have undergone thorough research and testing to guarantee quality.

Instant Knockout is one of those formulas. It strictly adheres to cGMP guidelines and is 100% safe for human consumption. No banned substances are on the ingredients list, making it ideal for athletes.

But what does it contain? Keep reading to find out.

Highlighted Features

  • 30 servings per container
  • 45mcg ( 1800 IU) Vitamin D3 per serving
  • 10mcg Vitamin B12
  • 5mg Vitamin B6
  • 500 mg Green Tea Extract
  • 1800mg Glucomannan
  • 300mg Caffeine Anhydrous
  • 100mg Cayenne Powder
  • 100mg L-Theanine
  • 10mg Black pepper extract

Other Ingredients with no established daily value

  • Magnesium stearate
  • Vegetable cellulose
  • Silicon dioxide
  • Microcrystalline cellulose



Instant Knockout Cut Formula Review

What makes Instant Knockout Cut an effective fat burner is the ingredient composition. It’s like no other. It has nine fat-burning ingredients that increase thermogenesis, suppress appetite, and boost metabolism.

Cayenne Pepper Seeds. This ingredient acts as a thermogenic fat burner. It forces the body to produce more heat that eventually burns calories. The correct dosage may improve insulin sensitivity, enhancing energy usage and storage.

Green Tea Extract. This ingredient is also a natural thermogenic agent. It contains catechins that help accelerate your body’s fat-burning process. It also acts as a mild appetite suppressant, ensuring you don’t eat more than necessary.

Additionally, green tea extract has antioxidants. It helps protect your body against free radicals that may cause oxidative stress.

Glucomannan. Glucomannan is a dietary fiber extracted from konjac root extract. It absorbs water and expands inside your stomach, making you feel fuller. It’s the perfect ingredient for appetite suppression. It also helps control your calorie intake without the hunger pangs.

Black Pepper Extract. This ingredient is essential for increasing nutrient absorption from other foods. The active compound is prevalent in many fat-burning supplements. And for good reason. It helps in improved fat metabolism and absorption. Plus, it helps in nutrient uptake as well.

Caffeine Anhydrous. While caffeine is not thermogenic, it helps in increased energy levels. As you deal with the challenging cuts, you might feel tired and need more energy. Caffeine is the perfect remedy for that to help you stay active. It enables you to stay focused and energized until the end of your workout session.

Instant Knockout Cut Price

Best Fat Burners in 2024One bottle of Instant Knockout Cut containing 30 servings worth one month’s supply costs $65.00 for a one-time purchase. Two bottles of the exact product cost $130.00, and three bottles plus one extra free go for $195.00. You also get free shipping in the US and UK when you buy two bottles and above.

One strong benefit with Instant Knockout Cut that we really like, is that if you purchase a 2 or 3-month supply, they provide a Boss Workouts training program for free. We have checked out the training, and it’s pretty impressive. 

Instant Knockout Cut Customer Reviews

Instant Knockout Cut has lots of positive reviews from customers. For example, there are tens of comments on the brand’s main website praising it for its effectiveness. The comments include photos and videos as evidence of the transformation.

We also looked for customer reviews on independent sites such as Amazon. Even there, the results were overwhelmingly positive. One user, Ian Pinches, wrote, “While taking 4 a day is a little frustrating, this product has enabled me to train longer & harder, and with noticeable improvements in shifting fat and toning muscle.”

Another one said, “I used Instant Knockout for 8 weeks. I was trying to shred the last bits of fat before the summer holidays. I noticed that I had much more significant energy within the first week. Now, even reaching PBs in the gym. The appetite-suppressing effects were able to stop me from snacking on chocolate bars. Heck, I couldn’t even remember crisps in between meals.

2. Hourglass Fit (Second best thermogenic fat burner)

Hourglass Fit Hourglass Fit is another best fat burner that helps you tackle challenging cuts. Unlike Instant Knockout Cut, this one is caffeine free. That means it’s safe for anyone sensitive to coffee.

The formula contains various unadulterated ingredients, including minerals, vitamins, herbs, and more. As the name suggests, it helps you achieve your desired hourglass figure. And yes, it’s primarily formulated with women in mind. But anyone struggling with excess fat can use it.

This scientifically formulated dietary supplement works primarily in two main ways. That is to suppress your appetite and boost heat production. As you can guess, it has well-dosed fiber and thermogenic ingredients.

Brand Overview

Hourglass Fit is also a product of Roar Ambition. Unsurprisingly, it’s of such high quality considering the same company makes Instant Knockout Cut. The brand also debuted in 2014 and has continuously gained a reputation for producing premium supplements.

As proof of its effectiveness and popularity, Hourglass Fit got named among 2021’s top five women’s fat burners. But make’s it tick? Let’s find out.

Highlighted Features

  • 30 servings per container
  • 1.7mg Vitamin B6 per serving
  • 1.1mg Vitamin B2
  • 125µg Chromium
  • 2.4µg VitaminB12
  • 8mg Zinc
  • 100mg Cayenne pepper extract
  • 3000mg Konjac root extract’
  • 150mg 5-HTP
  • 5mg black pepper extract



Hourglass Fit Review

Hourglass Fit depends on ten well-dosed and effective ingredients to help you lose fat.
They work in various ways to ease you through this fat-burning period.

B vitamins. Vitamin B2, B6, and B12 are worthy additions to a calorie-restricted meal. They help convert foods into energy, ensuring an active metabolic process. This energy comes in handy during your workout sessions.

Chromium. This ingredient is a trace mineral that balances your blood sugar levels and metabolism. It also blocks overreaction and unnecessary snacking. That makes it easier to avoid consuming more calories, thus hastening your weight loss journey.

Zinc. It’s a trace mineral that influences how your body handles fat and burns calories. According to NCBI, people struggling with obesity have low amounts of zinc. Therefore 8mg of zinc is a welcome addition to this supplement. (1)

Cayenne pepper. It’s an essential fat-burning ingredient extracted directly from chili peppers. This compound has an active component called capsaicin that warms your body, increasing calorie-burning capacity.

Konjac root extract. This ingredient contains glucomannan, a robust soluble fiber that helps you feel fuller for longer. That way, you have zero temptations to snack or overeat.

5-HTP. This ingredient comes in handy while dealing with cravings and mood. It boosts serotonin levels, thus improving your mood and making it easier to resist snacks. It’s also believed to act against hunger-inducing hormones like ghrelin, helping you reduce calorie intake.

Black pepper extract. It contains piperine or Bioperine, which increases nutrient absorption and digestion. It ensures your body gets the most out of each macronutrient, thus increasing the efficacy of your fat-burning efforts.

Hourglass Fit Price

One bottle of Hourglass Fit containing 120 easy-to-consume capsules worth one month’s supply costs $60.00. Two bottles containing 240 capsules worth two months’ supply cost $ 120.00. Three bottles plus one free containing 480 tablets worth three months’ supply cost $180.00.

The brand offers free delivery for orders above two bottles in the US and UK. But you can only buy from the official website.

Hourglass Fit Customer Review

Unsurprisingly, Hourglass Fit has numerous positive reviews from satisfied customers. For instance, there are tons of positive reviews on the official website.

There are plenty of women showing before and after images and videos of how the supplement has helped them achieve their body goals.

We also looked at customer reviews on independent sites like Amazon, and the response was the same. For example, one user wrote, “Pills are not big and go easy. Seems to work. Lost 1 pound already.’

Another one said, “I like this product. A lot of manufacturers and sellers tend to overstate the benefits. However, that is not the case this time because this product worked for me. I have to give it my highest recommendation. Five stars!”

3. Hunter Burn

Hunter BurnHunter Burn is another excellent fat burner from Roar Ambition. This nutritional supplement aids weight loss while preserving muscles and reducing hunger pangs. This one, too, does not use caffeine to boost your energy.

What raised our interest in Hunter Burn here at A Lean Life is the claim that it can help burn fat while preserving muscle mass. That’s something challenging to archive. Any pro athlete who has undergone a cutting phase knows how hard it is. But Hunter Burn claims to do this with ease.

That begs the question, what makes Hunter Burn different? Like other fat-burning supplements, this one, too, has thermogenic and appetite suppression properties. But it also adds two unique ingredients – L-Theanine and vitamin D3. (2)

It’s not often you find L-Theanine in a fat burner. Usually, it’s paired with caffeine in pre-workouts.

Brand Overview

Hunter Burn is a product of Roar Ambition under the brand name Hunter Evolve. The UK-based company promises to deliver high-quality supplements for mental and physical performance. And they have lived up to their word.

Hunter Burn is a powerful fat burner that combines natural ingredients with modern science. It promises to help you cut your body fat without causing muscle wasting or hunger pangs.

But what does it contain? Let’s find out.

Highlighted Features

  • 30 servings per container
  • 3000IU Vitamin D3
  • 3000mg Konjac root extract (glucomannan)
  • 200mg L-Theanine
  • 500mg White kidney bean
  • 125mg cayenne pepper
  • 200mg matcha green tea



Hunter Burn Review

Hunter Burn utilizes six key ingredients to boost fat burning. It works primarily in three ways. They include appetite suppression, fat burning, and enhanced energy levels. The plus ingredients help you retain muscles while losing fat.

Vitamin D3. Vitamin D exists naturally in the sunlight and in some food. However, your office and indoor gym-bound lifestyle don’t always allow you to get the necessary amount.

The 3000IU of D3 in each serving helps you get your daily dose. It supports your immunity, muscle recovery & maintenance, and metabolic functions.

Konjac root extract (Glucomannan). Like other fat-burning supplements, glucomannan helps reduce appetite by making you feel full. It is a dietary fiber that absorbs water and expands in your stomach. This effect tricks your body into believing you’re full and stops you from overeating. (3)

L-Theanine. This ingredient differentiates Hunter Burn from other fat burners in the market. The brand chooses it for two reasons.

First, it’s an amino acid that may reduce fat build-up and hence, helps you achieve and maintain a lean body. Secondly, while undergoing cuts, you often lose muscle fiber.

L-Theanine prevents this by preserving the muscle fibers as you shed fat and calories.

White kidney bean. This bean extract plays a critical role in carbs absorption in the body. In most cases, excess carbs transform into fat that gets stored, making you overweight.

As a supplement, white kidney bean extract reduces the breakdown of complex carbs. Such a simple action minimizes fat storage as carbohydrates pass through your body.

Cayenne pepper. This ingredient is an essential thermogenic that boosts your metabolism. It creates a mild sensation of heat in the body and helps you burn more calories.

Matcha green tea. Matcha contains the highest amount of antioxidants compared to other teas. It’s also loaded with nutrients that boost your energy levels.

Hunter Burn Price

One container of Hunter Burn containing 30 servings or 180 capsules worth one month’s supply costs $90.00. Two months’ supply (60 servings) costs $180.00, and three months’ supply (90 servings) plus 30 free is $270.00.

The company offers free delivery to US and UK customers for two or more bottles. But you only buy from the main website.

Hunter Burn Customer Reviews:

Like the rest of Rear Ambition fat burners, Hunter Burn enjoys a good customer review. For instance, the supplement has positive comments on the brand website.

One customer, Taylor Wetherell, wrote, “My energy levels are high. My motivation has risen- so I’m super happy I found this product!” Another one, Paul Taneja, said, “’ I am only a little over a month in, but I’m definitely noticing a difference physically.”

However, we also noted a few complaints about the price. Most people said that the product was too expensive. But they also concluded that the results were worth it.

4. Capsiplex Burn

Capsiplex Burn - Best Fat BurnerCapsiplex Burn is another fat burner worth a try. Like the Hunter Burn, this lets you shed excess weight and toning and harden your abs.

The supplement contains a special blend of ingredients like capsicum and chili. While ordinary chili can burn you from the mouth down your esophagus, this doesn’t. It’s a unique extract from chili that provides all the benefits without the burning sensation.

The primary action of Capsiplex Burn is to help you reduce weight via thermogenesis. It also relies on appetite suppression and energy production. The capsaicinoids compound mobilizes fat for energy production. It also generates heat to crank your metabolism and enhances rapid weight loss. (4)

Additionally, Capsiplex Burn is an all-natural supplement. As such, it causes fewer side effects than some of the other fat burners.

Brand Overview

Capsiplex Burn is a product of Wolfson Brands UK Limited. This Uk-based brand has been creating high-quality supplements since 2020.

While the company is relatively new, it has been among the most reputable brands globally. All thanks to its scientific-based formulas and customer-centered approach. It owns some of the biggest names in the sports and nutrition space, including PhenQ, Crazy Nutrition, TestoPrime, and more.

The company works with research centers, consumer nutrition brands, and experts worldwide. That ensures they have well-researched products that are safe and effective. 

Capsiplex Burn is one of these safe and effective products. It’s a non-GMO, gluten-free fat burner with no additives, preservatives, or fillers.

Here is what you can expect from Capsiplex Burn:

Highlighted Features

  • 30 servings per container
  • 16 mg Vitamin B3
  • 2.67mcg Vitamin B12
  • 1.7mg Vitamin B6
  • 150mcg Iodine
  • 500mg L-Arginine HCL
  • 800 mg L-Tyrosine
  • 170mcg Chromium
  • 250mg InnoSlim
  • 100mg Capsicum fruit extract
  • 200 mg caffeine anhydrous
  • 4.5mg Green coffee bean extract
  • 20mg back pepper fruit extract
  • 76mg green tea leaf extract



Capsiplex Burn Review

Capsiplex Burn is different from the usual fat burners. This supplement has several unique ingredients that help you reduce excess fat and boost energy levels. Here is a breakdown of each.

B-Vitamins. Capsiplex Burn contains vitamins B3, B6, and B12. They are essential for cellular health and proper body functions. They also help carry out metabolic and messaging functions promoted by the Innoslim.

Iodine. Iodine is readily available in your regular table salt. However, as you try to cut weight, you should also eat less salt. But this could also lead to iodine deficiency, which causes thyroid malfunction.

L-Arginine HCL. It’s not every day you’ll find L-Arginine in a fat burner. But when contained in such a supplement, this amino acid helps with lean muscle mass and metabolism.

L-Tyrosine. L-Tyrosine is very popular in fat burners. And for good reasons. It helps regulate thyroid function to suppress your appetite. It can also interfere with brain chemistry, keeping you motivated and away from snacks and junk foods.

Chromium. Most fat burners only concentrate on the physical aspects of your body, leaving out the brain. Very few seek to alter your brain chemistry and signaling. When used in Capsiplex Burn, it regulates your brain’s hormone signals and tricks it into thinking that you’re full.

InnoSlim. InnoSlim is a blend containing Astragalus and Ginseng. These two compounds target the very mRNA of our cells, instructing them to burn more fat and sugar for energy. As a result, you get more fuel for your workouts while cutting weight.

Capsiplex Burn Price

One bottle of Capsiplex Burn containing 30 servings worth one month’s supply costs $64.99. Two bottles plus one free one worth two months’ supply costs $129.99. Three bottles plus two free ones worth three months’ supply cost $194.99.

Customer Reviews

Unfortunately, the brand does not offer many customer reviews on the main website. However, we found several on social sites such as Facebook and Reddit. Most were positive, though some felt it was a bit pricey.

One satisfied user wrote, “Capsiplex Burn is a great product. I’ve been using it for three weeks. Now I can already feel the difference in my energy levels and fat loss. I definitely recommend it!”

Another one said, “I’ve been using Capsiplex Burn for four weeks now and can see the difference in my body shape. I’m extremely happy with the results and would definitely recommend it!”

Overall, we recommend Capsiplex Burn to anyone looking for an effective fat burner. It has all the ingredients and compounds to help you stay in shape.

5. Burn Lab Pro

The Best Thermogenic Fat Burner Supplements - Burn Lab ProBurn Lab Pro is the last best fat burner in our review. This one, too, uses thermogenic ingredients, capsaicin, to raise your temperature and burn more fat. However, it has a few more essential compounds that set it apart from its competitors.

The first unique ingredient is the forskolin extract. It’s found in the Indian coleus plant and has proven benefits in weight loss. Another one is the piperine. This antioxidant comes from black pepper and helps absorb other ingredients. (5)

Furthermore, Burn Lab Pro is vegan-friendly. It’s also free from GMOs, gluten, artificial sweeteners, and colorings. As for its effects on your body, it increases energy levels and metabolism. Plus regulates hormones, reduces hunger cravings, and provides optimal fat loss.

Brand Overview

Burn Lab Pro is a product of Opti-Nutra, a leading UK-based nutritional & dietary supplement manufacturer. The company has been providing superior-quality products since 2018.

The company takes pride in providing pure and natural ingredients. It also boasts cutting-edge technology and high standards of production. In fact, all its production facilities are FDA-approved, ensuring safety.

Burn Lab Pro is one of its products that has been well-received by customers. All thanks to its diverse ingredients that promise to burn calories and preserve muscle mass.

Highlighted Features

  • 30 servings per container
  • 90mcg GTF chromium
  • 1500 mg HMB
  • 262.5 mg calcium
  • 375 mg ForsLean
  • 3.75 mg BioPerine black pepper extract



Burn Lab Pro Review

Burn Lab Pro utilizes five ingredients to boost weight burn. While the primary way is through thermogenic effects, each component works differently. Here is a breakdown of the formula.

GTF chromium. GTF is a type of chromium that enhances insulin activity. As a result, it helps regulate blood sugar levels and boosts metabolism. Optimized insulin levels increase muscle strength, control appetite, and balance energy.

HMB. ß-hydroxy ß-methyl butyrate improves muscle growth. Research by the NCBI shows that HMB can help build muscles, muscle strength, and muscle recovery after workouts. (6)

The effects of HMB are more apparent when combined with a low-calorie diet and high-intensity exercises.

Calcium. Calcium strengthens bones and helps in fat Burn. It also reduces the risk of osteoporosis, especially for people over 50.

ForsLean. This is an extract from the Indian coleus plant. It stimulates hormones that boost the breakdown of fat tissues. It also improves your metabolic rate while developing muscles. Additionally, it can charge your testosterone levels for better performance.

BioPerine black pepper extract. This antioxidant found in black pepper helps in the absorption of other ingredients. That way, Burn Lab Pro can work faster and more effectively.

Burn Lab Pro Price

A box containing 30 servings worth one month’s supply costs $35.40. Two boxes of the same containing 60 servings worth two months’ supply cost $70.80 while purchasing three boxes with 90 servings will cost you $106.20.

You can find Burn Lab Pro on the brand’s website. It also offers a 30-day money-back guarantee, giving you peace of mind when purchasing the product.

Customer Review

As you would expect from a high-quality fat burner, Burn Lab Pro has received many positive reviews. Customers praise its ability to suppress appetite and promote quick weight loss.

The product has an average of 3.91/5 star rating on the brand website. The majority of the customers said they had better performance during workouts. They also noticed a significant reduction in their waist size.

One customer wrote, “It’s helping me out with staying lean while bulking.” Another one said, “I combined Burn with a 5-2 intermittent fasting program. The result has been very satisfying. In fact, myy target is to take off 25 pounds, and so far I have lost 1/2 that in less than 30 days.”

Overall, Burn Lab Pro is an effective and fast-acting fat burner. Its diverse ingredients help you burn calories, suppress your appetite and control blood sugar levels.

Bottom Line

If used wisely, fat burners can be a great tool in your weight-loss journey. With most having a thermogenic effect, they can safely boost metabolism and help you achieve your desired body. 

However, always check the ingredients first and consult your personal healthcare professional before using them.

Click to return to more info on the best fat burners based on your personal journey. Also check our review of the top thermogenic fat burners, as well as the best fat burner for men.

Picture of David Williams

David Williams

A diet and fitness enthusiast, David is an ex-Army Airborne Ranger and Infantry soldier with decades of fitness and wellness experience. A West Point graduate with a degree in engineering, he focuses on technical research related to fitness, nutrition, and wellness. He loves the beach, and spending time with his wife and daughters.


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  2. Mehta, F. (2021, January 20). What you should know about the benefits and risks of L-Theanine. Healthline.
  3. WebMD. (n.d.-b). Glucomannan: Overview, uses, side effects, precautions, interactions, dosing and reviews. WebMD.
  4. Capsaicinoids. Capsaicinoids – an overview | ScienceDirect Topics. (n.d.).
  5. MediLexicon International. (n.d.). Does forskolin work? uses, risks, and benefits. Medical News Today.
  6. D;, S. G. (n.d.). Beta-hydroxy-beta-methylbutyrate (HMB) supplementation and the promotion of muscle growth and strength. Sports medicine (Auckland, N.Z.). https://pubmed.ncbi.nlm.nih.gov/10966150/