Best Fat Burners (2025): Dietitian Reviewed

While we did pair with an expert to find the safest options on the market, you may still want to manage expectations. Just as a protein powder won’t miraculously grow your muscles, a fat burner won’t instantly shed pounds. If you want the best results, we recommend prioritizing a consistent exercise routine and a diet that’s rich in whole foods. We also recommend you consult a medical professional before trying fat burner supplements, especially if you have any preexisting conditions. That said, we’ve selected what we think are the five best fat burners available today to help you make a safe choice.

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Our team of expert testers has tried hundreds of the most popular supplements on the market today, using our comprehensive supplement testing methodology to find the best products for all folks.

Medical Disclaimer: This article is not intended to replace the advice of a healthcare or medical professional. For health concerns or medical guidance, contact your healthcare provider.

Best Fat Burners of 2025 

Best Fat Burners Comparison Table

Best Fat Burner Overall: Transparent Labs Recomp

Our Thoughts on Transparent Labs Recomp 

Transparent Labs Recomp includes some common fat burner ingredients such as caffeine and green tea leaf extract. It also includes two unique ingredients, one made of forskolin (ForsLean), and one of red chili extract (Capsimax). Forskolin is a root extract used in Ayurvedic medicine that has been studied for its potential glucose metabolism and fat reduction properties. However, most research on the ingredient has been animal studies, so forskolin’s effectiveness on humans is still unclear. Similarly, red chili extract has been studied for its potential weight reducing effects. However, while these ingredients may help support fat loss, more research is needed to create a firm connection between the two. That said, Transparent Labs Recomp is our top pick because of the unique combination of ingredients it offers, intended to support fat loss, maintain lean muscle, boost energy levels, and potentially curb cravings without excessive stimulants. We also like that it includes L-theanine to help reduce any possible jittery side effects.

Pete, our resident dietitian, tested this fat burner. His first impression of Transparent Labs Recomp earned a 5 out of 5 rating, with Pete noting that he liked the travel-friendly size. However, he rated the instructions just a 3 out of 5. “Start with one capsule, twice daily, to assess tolerance for the first three days, and then gradually increase the dosage,” he said. Pete noted that a recommended serving size is two capsules, but he suggests starting with one capsule twice daily to assess your tolerance for at least three days. Then, you can gradually increase the dosage until you reach the recommended amount.  

He rated it a 3 out of 5 for ease of swallowing the pill. Pete also said that the pill had no taste, however, you do need to take two servings per day, which can be inconvenient for some folks or easy to forget. 

Pete experienced no side effects or digestive issues after taking this fat burner. Overall, he said, “I like that this product goes a little lighter on the caffeine, at 125 mg per serving. At this dosage, consumers shouldn’t get any of the potential negative side effects from caffeine such as anxiety or jitters. The product also includes L-theanine which can help balance out the caffeine. The other ingredients may have some small benefits for fat metabolism.” 

Best Thermogenic Fat Burners: Jacked Factory Burn XT

Our Thoughts on Jacked Factory Burn XT 

Jacked Factory’s Burn XT is our top pick for the best thermogenic fat burner, thanks to its unique combination of Acetyl L-Carnitine HCL, green tea extract, caffeine anhydrous, Capsimax® cayenne pepper extract and BioPerine®, all of which work together to potentially help enhance the body’s calorie-burning capability and support fat oxidation. The inclusion of Capsimax® and caffeine together may help to increase your body’s thermogenesis, which supports your body to burn more calories by producing more heat. As with all fat burners, though, this will work best when paired with a healthy diet and exercise regimen. 

Pete tested Burn XT and gave the product a 5 out of 5 for his overall first impression. “The container is aesthetically pleasing and would definitely stand out on a store shelf,” he said. “The bottle is relatively small and would be easy to travel with, too.”  

When trying the product, he found the capsules easy to swallow, earning Jacked Factory a 3 out of 5 in this category. The instructions, he noted, indicate that “the recommended serving size is dependent on the ‘experience’ of the user. The initial use is one capsule per day, then regular use is one capsule two times per day, and experienced user use is two capsules two times per day.”  

When testing out the capsule, Pete described it as follows: “No taste, it is made of hypromellose instead of gelatin. There is no coating on the capsule.” He rated the overall taste as 3 out of 5. 

Pete rated the possible side effects of Burn XT as a 3 out of 5 as well, sharing some cautionary remarks: “A two-capsule serving contains 270 mg of caffeine, which is a strong dose and could elicit side effects.”  

There are clear instructions on the label indicating not to take this fat burner on an empty stomach. The label also advises not to take these capsules within six hours of going to sleep, and not to exceed four capsules in a 24-hour period.  

“It’s worth noting that taking four capsules per day would put you over the USDA’s recommended upper caffeine limit of 400 mg per day,” Pete says. If you are sensitive to caffeine or experience jitters or anxiety with stimulants, we recommend that you try Transparent Labs Recomp Stim-Free instead, as it is free of any stimulants. 

Best Fat Burner for Women: Legion Phoenix Fat Burner

Our Thoughts on Legion Phoenix Fat Burner 

Legion’s Phoenix Fat Burner is our pick for the best fat burning supplement for women. Though fat burners are not specific to any gender, we like that the Phoenix formula gives women the option to choose a stim-free version. Individual responses to caffeine are affected by body size and composition, so, folks with smaller bodies may prefer no caffeine. 

Phoenix also contains ingredients such as 5-HTP to potentially reduce hunger and cravings, and grains of paradise, which may help decrease visceral fat. It also includes a proprietary blend with Irvingia gabonensis, which studies have shown may support reduction in body fat. However, more research is needed on these ingredients to conclusively link them to body fat reduction and fully explore potential effects.  Pete noted the uniqueness of the inclusion of Irvingia IGOB-131, saying, “It’s not commonly seen in fat burner supplements. It is a patented extract of the African mango seed. Some clinical trials showed modest weight loss or metabolic improvements at a dose of 300 mg a day, which is the same dose in Legion’s Phoenix Fat Burner.”

He rated this fat burner as a 5 out of 5 for first impression, saying, “This product comes in a black container with a black and pink label. It’s easy to read and travel-friendly.” Pete also described the directions as easy to read, earning it another 5 out of 5 in this category. As with most other fat burner supplements, it’s recommended to start with a lower dose (like one capsule per day) to assess your tolerance. Our team likes the dosing of this fat burner for folks who are new to using supplements or are sensitive to caffeine for optimal results without jitters. 

After testing Legion Phoenix, Pete rated it a 5 out of 5 for both taste and ease of swallowing. “The capsule is a standard size; about the width of a quarter. The recommended serving size is three capsules a day.” If you’d prefer to take less to get a full serving, we’d suggest trying Transparent Labs Recomp, which is two capsules. 

Best Non-Stim Fat Burner: Transparent Labs Recomp Stim-Free

Our Thoughts on Transparent Labs Recomp Stim-Free 

Transparent Labs Recomp Stim-free is our choice for the best fat burner without any stimulants. For those who regularly drink a pre-workout, a stim-free fat burner may be preferred. It still contains ingredients that have been studied to potentially help burn fat, such as coleus forskohlii extract, which research has shown may reduce body fat while also maintaining lean muscle mass. However, it’s important to manage expectations, as it hasn’t shown vastly different results compared to a placebo.

TL Recomp Stim-Free also includes grains of paradise extract, known for its ability to potentially help activate brown adipose tissue to increase energy expenditure and reduce visceral fat, even without added stimulants. 

Pete tested this fat burner, rating it a 5 out of 5 for first impressions. “It comes in a white plastic container with a metallic white and blue label. It looks good, is easy to read, and travel friendly,” he said.

He rated the instructions a 3 out of 5 for ease of understanding and following, noting that there are some caveats to pay attention to within the directions. The directions recommend that you take two capsules twice daily 30 to 60 minutes before a meal. “Start with one capsule, twice daily, to access tolerance for the first three days, then gradually increase dosage,” Pete says. 

You may want to set alarms on your phone to ensure you remember to take this twice a day ahead of meals. The directions also recommend that you “never consume more than two capsules in a four-hour period and/or consume more than four capsules in a 24-hour period. Do not take within four hours of bedtime.” So, despite it being stim-free, it’s still best to avoid taking this fat burner in the evening. 

Pete experienced no side effects with this fat burner and did not experience any unpleasant taste or aftertaste from these capsules, rating the flavor a 3 out of 5. Those who would prefer a stimulant along with these ingredients may like Transparent Labs Recomp, which has 125 milligrams of natural caffeine. 

Best Fat Burner for Men: 1st Phorm L-Carnitine

Our Thoughts on 1st Phorm L-Carnitine  

It can’t be said enough: Fat burners aren’t a gender-specific product. But for men who like to stack their supplements, like mixing their L-carnitine with a creatine supplement, we recommend 1st Phorm L-Carnitine. Available as a mixable powder in five different flavors, 1st Phorn L-Carnitine is intended to support fat burning without heavy stimulants. The higher dose of L-carnitine may extend your exercise performance, endurance, and power, which may help support further fat loss, according to a 2021 study. 

Pete tested this fat burner, rating it a 5 out of 5 for first impressions. 1st Phorm L-Carnitine comes in a white container with a metallic white and blue label. Pete said, “The label is easy to read and includes scannable QR codes for more information about the product. The scoop was easy to find, it’s small and the container was easy to open.” 

The product mixed well with eight ounces of water, earning a 5 out of 5 for mixability. “After shaking for sixty seconds, the product is fully dissolved; it has a smooth texture with no visible chunks or further shaking required,” Pete said. 

Our tester rated the taste a 3 and the sweetness a 5, noting the inclusion of artificial sweeteners in his rating. “The product is sweetened with both sucralose and acesulfame potassium, coming off as pretty sweet, bordering on being too sweet.” Pete liked the berry lemonade flavor and noted that it is “isn’t gritty or foamy, but it does have a chalky aftertaste.” 

Pete thinks 1st Phorm L-Carnitine is a good alternative choice if you dislike taking pills and prefer a flavored powder that you can drink. “The L-carnitine is dosed well at 1,500 milligrams, and the fucoxanthin dosed at 2.5 milligrams may help with fat oxidation.”  

Fucoxanthin is part of the edible brown seaweed and is often found in macro- and micro-algae. It may help your body burn fat by stimulating genes and enzymes, which increases your metabolic rate, supports your body as it breaks down lipids, and can also activate thermogenesis in white adipose tissue, which is the most frequently occurring type of fat in your body. 

How We Tested and Selected the Best Fat Burners 

We tested and evaluated fat burning supplements and scored them on a scale of 1-5 for factors such as first impressions, directions that are easily understood, taste, side effects, and price per serving. Our testers evaluate the products based on their own individual experiences and preferences. We then review their testing feedback and data to share our findings and recommendations with you.

Formula 

We work with a registered dietitian (RD) during testing to find the most effective and safe fat burning formulas. We primarily focus on supplements without artificial sweeteners and other additives, while prioritizing clinically dosed formulations. 

However, especially with fat burners, there’s no quick fix or magic pill when it comes to fat loss. Our team can’t stress enough that a balanced diet and consistent exercise routine are the main key to fat loss. That said, if you’re wanting to buy a fat burner regardless, we want to offer the safest options possible, as there are a lot of sketchy products out there.

Serving Size 

When evaluating supplements that are in capsule form, we focus on the serving size and ease of swallowing. Both of these aspects can impact your experience as a consumer, and whether or not you’ll continue taking the supplement long-term. In general, smaller, well-shaped pills are easier to swallow.

Particularly with fat burners, we like to prioritize products that don’t involve a multitude of servings per day. 

Taste and Texture 

Flavor is an important part of our testing process. We ask our testers to provide feedback on the taste, texture, and flavor of each supplement that they test. For fat burning supplements, we focus on taste of the capsule (if any) as flavors are sometimes added to the casing materials. We also ask testers to share if they experience any aftertaste. 

Third-Party Testing 

We aim to select fat burning supplements that have been third-party tested. Third-party testing ensures independent verification of safety, purity, as well as nutrition label accuracy. This helps to reduce the risk of mislabeling or underdosing. Third-party testing also checks for harmful substances such as heavy metals, pesticides, and more for safety. For athletes, third-party testing is paramount to knowing that the fat burning supplement that they’ve chosen does not contain any banned substances. The FDA (U.S. Food and Drug Administration) does not regulate supplements, so it’s vital to have independent testing done to ensure safety, accuracy, and quality. 

Side Effects 

Our testers carefully monitor for any side effects experienced both during and after taking fat burning supplements, systematically recording any experiences of stomach upset, changes in energy levels, and other symptoms. By keeping detailed logs of reactions such as nausea, cramping, bloating, jitteriness, and headaches, they help identify general trends in tolerability and what to look out for. 

Value 

When considering value, we place a higher value on brands that source their ingredients in America and have certifications, such as Informed Choice.

How to Find the Best Fat Burner for You 

Everyone has different fat burner supplement needs depending on your fitness goals, dietary needs, allergies, and pre-existing health conditions.  

Here’s what to consider when selecting the best fat burner for you. 

Formula 

When choosing the best formula for a fat burner, it’s important to remember that everyone’s dietary preferences and sensitivities are unique. We recommend checking for common allergens, artificial ingredients, added sugars, or stimulants, choosing what fits best with your health needs. If you’re sensitive to caffeine or have a digestive condition, you may want to prioritize clean and transparent labeling, where each ingredient and dose is clearly listed, not disguised within a proprietary blend.

The best fat burners are made with formulas based on scientific studies and are free from added fillers or artificial ingredients. Most importantly, if you are considering a fat burner, especially if you have a preexisting condition or already take medications, we recommend that you speak with your doctor before starting, as some dangers have been documented to be associated with fat burners. 

Your Fitness Goals 

Every athlete and gym-goer has individual training goals in mind: you might be aiming to burn fat, get lean, increase your daily energy or endurance. When choosing a fat burning supplement, it’s important to consider your workout intensity, performance goals, and personal preferences such as caffeine or stimulant tolerance. 

Expectations 

When considering supplementing with a fat burner, it’s important to keep your expectations in check—these supplements aren’t miracle pills and won’t melt fat away on their own. While some ingredients in fat burners may help support the body’s metabolism, energy levels, and appetite control, the effects are usually modest and are not a replacement for eating balanced meals made of whole foods and prioritizing an exercise routine. It’s best to approach fat burners with a realistic mindset and ensure that your health and safety remain the top priority. 

Before you add fat burners to your supplement routine, we recommend that you prioritize healthy eating and consistent exercise to support fat loss. 

Cost 

It’s important to review a fat burning supplement’s ingredient list and formulation before purchasing. Supplements tend to be expensive, so reviewing added stimulants, flavors, and the form (capsules or powder) of the supplement can help you budget when making your purchase.  

Third-Party Testing 

When looking for a new fat burning supplement, we recommend checking that the supplement has been tested by an independent third party. Third-party testing ensures independent verification of safety, purity, as well as nutrition label accuracy. This helps to reduce the risk of mislabeling or underdosing. Third-party testing also checks for harmful substances such as heavy metals, pesticides, and more for safety. 

Potential Benefits of Fat Burners 

Fat burners are designed to support weight management and have several benefits. Effectiveness and benefits can depend on ingredients and dosing at clinical levels. Here are some benefits: 

• Thermogenesis: Fat burners are often formulated with ingredients intended to increase thermogenesis. This is the process of heat production in the body that helps raise metabolic rate and calorie expenditure. Ingredients such as caffeine, capsaicin/cayenne pepper extract, and green tea extract are commonly included and have been shown to potentially help boost your resting energy expenditure and caloric burn. For example, cayenne (capsaicin) and green tea have demonstrated an increase in fat burning in some studies and multi-ingredient thermogenics may also lead to an increased metabolic rate over several hours after consumed. However, as mentioned, you’ll see the best results when you pair supplements with a healthy diet and exercise routine. 
• Lipolysis: Lipolysis is when your body breaks down stored fat into free fatty acids for energy. Several fat burner ingredients are linked to enhanced lipolysis, including L-carnitine, green tea extract, forskolin, and bitter orange.  
• Appetite suppression: Natural appetite suppressants included in fat burning supplements are 5-HTP, green tea extract, and garcinia cambogia. These ingredients have been shown in studies to help decrease sensations of hunger, which may help minimize your cravings. 

How to Take a Fat Burner Pill 

When taking a fat burner supplement, it’s vital to closely follow the instructions printed on the supplement container and not to exceed the recommended maximum dosage. Taking the right dose helps to optimize the benefits while minimizing risks, such as a headache or nausea. Since each formula differs in strength, it’s good to check for any timing advice on the label—some fat burners are best to take thirty to sixty minutes prior to a meal or before a workout in the morning.

If you take any prescriptions or are managing any health conditions, we also recommend talking with your doctor about any supplements you’d like to add to your routine. 

What to Avoid in Fat Burner Supplements 

When shopping for fat burner supplements, it’s best to avoid products that haven’t been independently third-party tested. Third-party testing is important to safely verify what’s in the product is listed in correct amounts on the label. Products without third-party verification may contain inaccurate dosages, hidden stimulants, or even potentially dangerous ingredients. 

Transparent labeling is also helpful if you are avoiding stimulants or need to check for possible interactions with existing medications or other supplements that you take. 

We also recommend that you avoid supplements without customer reviews, ratings, or feedback. Choosing publicly reviewed, transparently labeled, and independently tested fat burners will help to ensure your safety and wellbeing. 

Frequently asked questions 

Are fat burners safe?

The safety of a fat burner depends on the supplement’s ingredients, formulation, and third-party testing results. Although many people can tolerate fat burners, clinical studies and case reports have found risks, including but not limited to: heart palpitations, headaches, and insomnia, as well as some more serious complications such as liver failure. Most harmful ingredients have been banned (such as ephedra), but due to the lack of supplement regulation by the FDA, we recommend starting low and slow with a fat burning supplement, following the brand’s instructions and warnings carefully. Before you try a fat burner, it’s best to consult a medical professional.

What is the most effective fat burner?

Transparent Labs Recomp is our pick for the best overall fat burner because of its unique ingredient formulation designed to help support fat loss, maintain lean muscle, boost energy levels, and curb hunger cravings without an excessive amount of stimulants.

If I take a fat burner, can I stop my diet?

No, a fat burner should only be taken as a complementary supplement to aid your exercise regimen and healthy, whole foods diet. A fat burner is not a substitute for a healthy eating routine and is not a shortcut to sustainable weight loss.