The Best Fat Burners of 2025, With Expert Advice from an RD

Why We Like It

Let’s be honest, even the best fat burner supplement won’t just torch fat on your body. But paired with a calorie deficit and exercise routine, they may be able to help encourage your progress. Considering the ingredients, third-party testing, and transparency, we recommend Transparent Labs as our top fat burner overall.

“I’m usually hesitant with fat burners, but I appreciate that Recomp has been tested by a third party,” according to Chelsea Rae Bourgeois, RDN, who rates the formulation at 3.5 out of 5. “I also like that Transparent Labs provides research-backed ingredients.” Still, she notes that fat burners aren’t necessarily appropriate for everyone, and individuals should consider their unique health profile before adding one to their routine.

One serving includes 300 milligrams of green tea leaf extract, 250 milligrams of forslean (10% forskolin), 125 milligrams of natural caffeine, and 50 milligrams of capsimax (red pepper extract). However, these are all relatively small doses, according to Bourgeois. Considering you have to take multiple doses per day, though, that makes sense.

That being said, we had to give the dosage convenience a 3 out of 5. Taking multiple servings per day can be tedious. Transparent Labs does recommend starting with one capsule twice daily, though, to assess your tolerance. 

“I like that Transparent Labs doesn’t promote Recomp as a magic pill,” Bourgeois says. “If you’re sensitive to caffeine, the multiple doses of caffeine may not be ideal for you.” So, for those who like to train in the evening, this pick may not be ideal.

“The price is pretty good for what you’re getting, but it’s not the cheapest fat burner on the market,” says Nick English, BarBend expert reviewer. Technically, one serving is only $0.92. However, you do need to take more than one serving daily, which technically increases the cost. As such, we score the cost at 4 out of 5.

Why We Like It

There’s no one best fat burner pill that’s biologically more suited to one gender over another — your metabolism, hormone levels, and fat-loss goals are highly individual, regardless of gender. That being said, Jacked Factory Burn XT earns our title of “best fat burner for men” not because it’s formulated only for men, but because it includes several widely-used ingredients that may align with common goals like increased energy, appetite control, and fat metabolism — which many males tend to prioritize in their training and supplement routines. That said, these same ingredients may benefit athletes of any gender.

This supplement contains a few common fat burner ingredients, like l-carnitine. Although a supplement can’t do as much as a fat-loss-focused diet and workout routine, l-carnitine may help you lose weight. (2)

“I’m generally not a fan of fat burners, but this contains fewer questionable ingredients than others on the market,” according to Chelsea Rae Bourgeois, RDN, who rates the formulation at 3.5 out of 5. “They should still be included mindfully and under the guidance of a doctor, if possible.”

You also get 225 milligrams of green tea leaf extract, which may help promote your weight-loss journey and control blood sugar levels. Each serving also provides 135 milligrams of caffeine, which can increase energy levels, while 25 milligrams of cayenne pepper fruit extract is intended to help increase your calorie burn through thermogenesis. 

“The research on acetyl l-carnitine and fat loss is mixed, but I like that Jacked Factory is using a compound that’s naturally made in the human body as a primary ingredient,” Bourgeois says. We also like that the bottle provides supplement facts for one- and two-capsule servings. However, you do need to take two doses per day, so we score the dosage convenience at 3 out of 5.

If you are considering doubling up your dose, you’ll want to take note of the doubled caffeine content. “If you’re sensitive to caffeine, Burn XT might give you some jitters,” says Bourgeois.

We rate the cost per serving at 5 out of 5, too. Each 60-serving bottle costs about $28.54, or around $0.48 per one-capsule serving, making this fat burner fairly affordable compared to others. However, given that you need to take multiple doses per day, this does up the cost.

Why We Like It

As mentioned before, there’s no one fat burner supplement that’s biologically engineered for women more than men — most ingredients work the same across genders. However, we do recommend Legion’s Phoenix formulation as the best fat burner for women based on its blend of appetite-supporting and metabolism-boosting ingredients, which may align with fat-loss goals that are common among women. Still, this product can be just as effective for men, too.

This is a pretty complete fat burner, earning a 3.75 out of 5 for formula, according to Chelsea Rae Bourgeois, RDN. “Legion Phoenix supplies the body with many important nutrients, many of which can help support weight management efforts,” she says.

It’s got 5-HTP, caralluma fimbriata, and forskolin, which all may help increase your metabolism, suppress your appetite, and burn body fat. 5-HTP may not be safe for everyone, though, according to Jillian Kubala, RDN. People taking certain medications (like SSRIs, MAOIs, or tricyclic antidepressants) should check with a doctor before taking this supplement. 

“While they may offer some benefits, herbal natural ingredients aren’t appropriate for everyone,” Kubala adds. So, if you have pre-existing health conditions or are taking other medications, you may want to chat with a doctor or steer clear of this product.

In addition to these less common ingredients, this fat burner also contains 200 milligrams of caffeine and a dose of B vitamins, which are more common in fat burning supplements. Plus, you’ll find a kick of L-DOPA, which can help increase focus and reduce brain fog — a great asset if you are hitting your workouts hard in the gym. Plus, we score the versatility a 4 out of 5 since you can purchase Legion Phoenix in a stim-free formulation, perfect for avoiding any jitters while also dealing with evening workout struggles.

One 30-serving bottle is $49.99, which is about $1.67 per serving, earning Phoenix a 3.75 out of 5 for price. Plus, this one is available on Amazon Prime, so you can get it in a matter of days. We appreciate that each serving is three capsules, too, which allows this fat burner to be more portable than a powder. However, “if you don’t like swallowing pills, that could be a deal breaker,” adds Bourgeois.

Why We Like It

Most fat burner supplements contain a pretty big dose of caffeine, which isn’t exactly ideal for athletes who are sensitive to caffeine or enjoy training in the evening. Luckily, Transparent Labs Recomp offers a stim-free version that can pair perfectly to your best non-stim pre-workout for jitter-free weight loss.

“Recomp Stim-Free uses research-backed ingredients, but that doesn’t eliminate the risks associated with fat burners,” according to Chelsea Rae Bourgeois, RDN, who scores the formulation a 3.5 out of 5. “Fat burners are not appropriate for everyone, but I appreciate that Recomp Stim-Free has been tested by a third-party lab.”

Unfortunately, the dosage isn’t the most convenient when it comes to promoting effective weight loss outright. “You have to take multiple doses of Recomp Stim-Free daily to see the purported effects,” says Bourgeois. Transparent Labs recommends taking two capsules twice daily about 30 to 60 minutes before eating. We had to give this product a 3 out of 5 for dosage convenience, as you do have to keep the supplement handy multiple times per day. For those traveling or eating on-the-go, this probably isn’t too convenient. If you’re looking for a single-dose per day, we suggest looking at a fat burner supplement like Legion Phoenix.

When it comes to cost, Recomp Stim-Free isn’t the priciest pick. One serving is only about $0.92. However, our team did give this product a 4 out of 5 for cost, as you do have to take multiple servings per day. Ultimately, this drives up the price.

Why We Like It

As one of the best carnitine supplements, 1st Phorm’s L-Carnitine isn’t technically a fat burner but may help promote fat loss alongside a calorie deficit and consistent exercise. “…L-carnitine [may] support the body’s biological processes to reduce fatigue during your workout and efficiently utilize fatty acids,” says Chelsea Rae Bourgeois, RDN. However, larger studies are still needed to directly connect carnitine supplements with weight loss, according to the NIH. Nevertheless, the 1,500 milligrams of carnitine per serving does meet (and exceed) the clinically-researched dose.

“The 1,500 milligrams of L-carnitine per scoop is very close to the researched recommendation of 2,000 milligrams daily,” according to Chelsea Rae Bourgeois, who gives the formulation a 3.5 out of 5 rating. “However, it may be overdoing it, as L-carnitine is found in various food sources.”

This formula also includes 200 milligrams of green tea leaf extract and 2,500 milligrams of fucoxanthin. This is an ingredient that’s found in brown seaweed and contains powerful antioxidants. Some studies have suggested that fucoxanthin may have some anti-obesity effects, but more research is needed. We don’t love that the formula uses sucralose and artificial flavors, though.

1st Phorm’s L-Carnitine comes in five different flavors, which is unique when compared to other fat burners we’ve tested. We rate the convenience at 4 out of 5, as you can combine with other powders in your supplement stack like essential amino acids or other goods that make up your healthy diet. Considering there’s no unflavored option, it may not mix well with other flavored products, though. “It [also] contains artificial sweeteners that many people cannot tolerate,” adds Bourgeois.

The price point for this product is pretty approachable, especially compared to some of the other fat burners on this list. One 60-serving container costs $42.99, which is about $0.71 per serving. Our team scores 1st Phorm L-Carnitine at 4.5 out of 5 for cost per serving, as it’s pretty budget-friendly, though it is recommended to take two scoops per day.

Why We Like It

BulkSupplements Berberine HCl has a pretty simple formula, as it only contains one ingredient with zero additives. Berberine is an ingredient found in a variety of plants and has been thought to have weight-loss-benefit properties. Right now, research has found that berberine may help decrease fat levels, however, these preclinical studies were conducted on rats, making it difficult to assess how berberine supplements may affect humans. (7)

“There is still so much to learn about berberine and its effects on fat loss,” Chelsea Rae Bourgeois, RDN, says, rating the formulation at 2.5 out of 5. “In addition to the limited research, the potential for medication interactions really gives me pause.” Plus, she notes, although the company claims the supplement is third-party tested, there’s no information about who does the testing.

This supplement is an unflavored powder, making it easy to mix with other supplements in a smoothie or your best shaker bottle. We did have to give the dosage convenience a 3.5 out of 5, though, as this doesn’t come with a scooper. And considering the serving size is one-fifth of a teaspoon, a food scale may be needed.

Our team does like that this product comes in bulk options, which is great for athletes who want to save a little extra. Price-wise, this product earned a 5 out of 5. One 50-gram container contains 100 servings and only costs $21.96. That’s about $0.21 per serving, which probably falls within most athlete’s budgets. “There isn’t any fluff in BulkSupplements’ Berberine HCl,” says Bourgeois. “You’re paying for berberine, and that’s what you get.”

Why We Like It

Green tea extract is among the most common ingredients you’ll find in most fat burner supplements. So, if you don’t want to fully dive into a fat burner pill, Thorne Green Tea Extract capsules can be an alternative to consider. One capsule provides 250 milligrams of decaffeinated green tea extract, which may help support weight loss, according to the Cleveland Clinic.

“In the world of weight loss supplements, green tea has likely been studied the most,” says Chelsea Rae Bourgeois, RDN. However, as with most of the best supplements for weight loss, the connection between weight loss and green tea extract is pretty modest. Green tea may help increase your total fat burn while you’re exercising and recovering but different studies show different results. (6) So, more research is needed for a firm connection between the two. 

“The research has shown that green tea extract may offer many benefits for the average healthy adult,” according to Chelsea Rae Bourgeois, RDN, who rates this formula at 4 out of 5. “Camellia sinensis, where Thorne derives their green tea extract from, has been linked to positive effects on weight management, diabetes control, and cardiovascular health.”

For dosage convenience, we gave this product a 3.5 out of 5. While the serving size is one capsule only, Thorne recommends taking two to three servings daily. “Some experts warn that green tea extract products, especially in pill form, can have negative effects on the liver,” says Bourgeois, who recommends discussing whether or not this supplement is right for you with your doctor.

These aren’t the most budget-friendly capsules, either, when compared to other fat-burning pills we’ve trialed. Yes, one 60-serving container only costs $30, or $0.50 per serving. However, considering you need to take up to three servings per day, that’s really more like $1.50 per day. So, in this category, our team gave Thorne a 3.5 out of 5.