We know that the term “fat burners” can bring to mind “magic beans,” but there’s actually a lot of really interesting evidence, both clinical and anecdotal, supporting their use as part of a well-planned fat loss regimen. Whether you need to cut for a physique show or you’re looking to shed some fat, these kinds of products may indeed have their place when they’re used judiciously and under the supervision of your doctor.
We looked at all the most popular and the most underrated fat burners on the market to decide on the best. We discuss the precise criteria we used to land on these brands below but it comes down to evidence: what does the science actually say, are the doses in line with what was used in studies, and are the doses transparent and effective?
Not all ingredients are created equal, either. Some, like capsaicin, have reams of studies supporting their role in thermogenesis whereas hordenine has a couple of promising studies, but it needs more research. That doesn’t mean it’s useless or that we don’t like seeing it in fat burners, but it’s good to have a balance of ingredients that are well supported.
There’s also the fact that there are a wide variety of ways that these ingredients can affect your waistline: appetite suppression, fat oxidation, increased thermogenesis, and decreased calorie absorption are the most popular.
After rigorous research and analysis, these are the 5 that best measured up.
Best Women’s Fat Burner Picks
No Artificial Ingredients
This fat burner includes multiple ingredients to promote fullness and increase fat burning, such as garcinia cabogia, turmeric, and much more.
Research Backed Doses
Transparent Labs Fat Burner
Transparent Labs Fat Burner
This fat burner contains research suggested ingredient amounts and comes at a reasonable price.
High In EGCG
Phoenix Legion comes with an extra absorbable form of synephrine and a high dosage of EGCG to promote its fat burning properties.
This fat burner is dosed heavily with glucomannan, green tea (though no mention of EGCG), green coffee, cayenne, and black pepper.
Fat Burning Staples
This supplement contains fat burning staples such as capsaicin and black pepper extract.
Read further below for even more categories and picks!
Editor’s note: The content on BarBend is meant to be informative in nature, but it should not be taken as medical advice. The opinions and articles on this site are not intended for use as diagnosis, prevention, and/or treatment of health problems. Speak with your physician before undertaking any new weight loss regimen.
What Is a Fat Burner, Anyway?
There are several different ways these products can impact your body fat and they can be direct or indirect. It’s important to understand this; simply drinking a big glass of water before a meal will probably blunt your appetite. Eating more high-water foods like lettuce and watermelon will keep you fuller for fewer calories, as will high fiber foods. Yet water and watermelon are seldom called “fat burners.”
Calories are far and away the most important part of weight management and while some of the ingredients below help to blunt appetite, others take a different approach.
Here are some of the most popular ways fat burners work:
Increasing Fat Oxidation: A 2004 study in Nutrition noted that there are a lot of different exercises and dietary strategies to help the body burn more fat for fuel, as opposed to more carbs for fuel.(1) If something increases fat oxidation, it’s about as close to a literal “fat burner” as you can get. Popular examples include green tea extract (more specifically the antioxidant EGCG) and l-carnitine.
Increasing Metabolic Rate: There are some compounds that we’ll get into below that have been seen in some studies to slightly elevate a person’s resting metabolism. That means that by taking the pill, you burn more calories than if you hadn’t taken the pill. Capsaicin, a compound that makes peppers spicy, is perhaps the most common but there’s hordenine and synephrine are also growing in popularity.
Decreasing Appetite: There are a variety of ways to decrease hunger, from prompting hormonal changes to starches that expand in the stomach. Given that the previous two entries seldom add up to more than a hundred extra calories burned, appetite suppression may be the most important part of fat burning. Glucomannan, made from the Japanese konjac tree, is one of the best supported examples but 5-HTP and psyllium husk also have a lot of evidence.
How We Decide the Best
1. Scientific evidence
We can’t pretend there’s 100 percent scientific consensus on every ingredient we consider effective, but it’s still important to be able to recognize what has a good amount of studies supporting it, a decent amount, and those that aren’t well supported at all. There are also ingredients that may indeed have beneficial effects but their marketing claims are too over the top: for example, there are a lot of products that will tell you to take a supplement before a meal and you won’t absorb any of the carbs. We cut these products out.
Raspberry ketones are a good example of something that could work, but virtually nobody uses the dose that produced effects in studies. Now, that doesn’t mean we’re going to disqualify any supplement that has them — if a product has 5 perfectly dosed ingredients and 1 imperfectly dosed ingredient we’re not going to throw it in the trash — but a lot of ineffective doses will hurt a product’s rating.
3. Proprietary Blends
Way too many fat burners contain interesting ingredients, but don’t tell you how much of each ingredient they contain. This factors against them for inclusion on our list because if we don’t know the dose, it’s hard to know just how effective the product is.
We also need to emphasize here that fat burners vary a lot in their ingredients — some lean more on appetite suppressants than increasing fat oxidation, and so on — so it’s pretty tough to decide which of two fat burners is better value when their ingredients are totally different. Still, $2 per day is a good threshold.
Keep reading after the products below to see the top 10 fat burning ingredients on the market!
Best Female Fat Burners
Our in-depth review of this product involved poring over numerous studies and interviewing one of their success stories, who confirmed to us what we already knew: you can’t just pop a fat burner and expect to lose weight “when you’re still having like ten Snickers a day and lounging on the couch.” But Leanbean does appear to make it easier to resist cravings and maintain energy levels during a calorie deficit.
A big part of the appeal is glucomannan, a thickener and gelling agent made from the root of the Japanese konjac plant that studies suggest can produce significant appetite suppression.(19) The ingredients list includes other fat burner stalwarts like cayenne pepper and green tea along with black pepper extract, which may also help to increase metabolism according to a 2016 paper from the Proceedings of the National Academy of Sciences of the United States of America.(20)
It seems a little low in green coffee extract and raspberry ketones, but that doesn’t mean this is ineffective all around — we were pretty impressed. The cost comes to about $2 per day.
- No artificial ingredients
- One pill per serving
- Great for appetite suppression
- Money back guarantee
- Some ingredients, like raspberry ketones, aren’t well supported
- May increase thirst
- May cause brief stomach discomfort
2. Transparent Labs Fat Burner
Transparent Labs have done their homework. This is a company that spends a lot of time citing their studies: there’s a hefty dose of the Indian herb Coleus forskohlii, a dose that a 2005 randomized, double-blind, placebo-controlled study in Obesity Research linked with “a significant increase for lean body mass” and lower body fat.(21) There’s also a big hit of EGCG-dense green tea extract, some theanine and tyrosine to help improve focus, some cayenne pepper, and a dose of synephrine. It’s not quite as good at appetite suppression as Leanbean but it’s still a phenomenal, research-backed product.
Note that Transparent Labs also has a stimulant-free version for the same price (which is just called Transparent Labs Stim-Free Fat Burner), but the ingredients are pretty different: it still has forskolin and cayenne but instead of tea, theanine, synephrine, and tyrosine there’s rhodiola (known for helping focus), acetyl-l-carnitine (for body composition) and fucoxanthin (a carotenoid that might reduce abdominal fat).
Cost is about $1.60-$1.80 per day.
Transparent Labs Fat Burner Pros
- Reasonably priced
- Research-backed doses
- Good blend for fat oxidation
Transparent Labs Fat Burner Cons
- May not be great for people sensitive to caffeine
- Not the best at appetite suppression
- Not vegetarian
3. Legion Phoenix
Another company making serious waves in the industry, Legion has two fat burners but we think Phoenix is the better choice. (The other, Forge, is more of a pre-workout.) It’s got the same dose of forskolin as Transparent Labs, it has far more EGCG than any other product on this list, and it’s got synephrine, naringin, and hesperidin. These are all extracts from citrus fruits which appear to increase the metabolism when used together, according to a 2011 study published in the International Journal of Medical Sciences.(22)
What’s interesting is that this also contains salicin, which might amplify the effects of synephrine — people often stack synephrine, salicin, and caffeine, which is why it’s recommended you take Phoenix with some coffee.(23) At a little over a dollar per day, it’s very reasonably priced.
Legion Phoenix Pros
- Extra absorbable form of synephrine
- Very high in EGCG
- Reasonably priced
Legion Phoenix Cons
- 5 capsules per serving
- Designed to be used with caffeine
- May increase hunger
4. Instant Knockout
Originally developed for fighters needing to cut weight — and those guys take cutting weight very seriously — this product is a little similar to Leanbean in that it leans heavily on glucomannan, green tea (though no mention of EGCG), green coffee, cayenne, and black pepper. It’s actually higher in cayenne pepper and it’s also got chromium picolinate, which a meta analysis in the International Journal of Obesity and Related Metabolic Disorders suggested might help a little bit with weight loss.(24)
The product explicitly states that it’s a great product for women, but it has a sizable 350 milligrams of caffeine per daily serving, which may put off some customers. The cost is about $2 per day.
Instant Knockout Pros
- Particularly effective appetite suppressant
- Good source of chromium picolinate
- Money back guarantee
Instant Knockout Cons
- Very high in caffeine
- No mention of EGCG content
- Low in green coffee
PhenQ prominently features Capsimax, a blend of capsicum, black pepper, caffeine, and Vitamin B3 which we’ve established have links with weight loss. The ingredients also list chromium picolinate (not that much) and some l-carnitine fumarate which some suggest may help the body more effectively burn carbs, but evidence is lacking. There’s also some nopal, a cactus extract that seems to be a surprisingly effective hangover cure.(25)
PhenQ makes a few claims that made us raise eyebrows, like the ingredient α-Lacys Reset® helped a group lose 7.24% body weight and that capsicum makes “the body burn calories up to 10 times more quickly than normal.” (We’re not so convinced on that.) But there’s still good evidence that it works more effectively than most of its competitors. A little pricier than usual at $2.30-$2.50 per day.
- Contains both capsaicin and black pepper extract
- Contains extra calcium
- One pill per serving
- A little low in chromium picolinate
- Not a ton of evidence for l-carnitine fumarate
- Could use more supporting evidence
[Read more: 8 all-natural fat burners.]
10 Common Fat Burner Ingredients
Here are some examples of super common ingredients you can expect to find in fat burners.
Stimulants appear to help with fat loss, not just because of the extra energy but also because caffeine seems to increase adrenaline, which appears to help break down fats.(1) Plus, it might help to increase caloric burn as well, albeit in the same neighborhood as chili pepper — under 100 calories a day, according to research published in the American Journal of Clinical Nutrition. (2)
Another popular stimulant, this is an alkaloid that’s derived from Central Africa’s yohimbe tree and while it may help reduce appetite, most research revolves around its apparent ability to reduce fat. A 2006 study in Research in Sports Medicine, for instance, saw that it soccer players lost two more body fat percentage points than a placebo group over three weeks.(3)
Spicy food is meant to increase your metabolism and some studies do suggest that might be the case. Many of these supplements contain extracts of cayenne or other chili peppers but capsaicin is the key ingredient here. Studies published in Journal of the Medical Association of Thailand and the American Journal of Clinical Nutrition estimate that it’s probably no more than 5 to 50 extra calories per day.(4)(5)
This molecule found in plants is pretty under researched but it has been called a fat burner because of its association with noradrenaline. A 2009 study in the Journal of the International Society of Sports Nutrition concluded that supplementing produced “a significant increase in energy expenditure” along with favorable changes in mood and blood pressure.(6)
Sometimes called bitter orange extract, a placebo-controlled study in the International Journal of Medical Sciences found that 50 milligrams of the stuff increased the participants’ metabolism by 65 calories without increasing hunger.(7) When combined with food, the calorie burn could be twice that amount.(8)
Also called ALCAR, there’s good evidence it can help to improve focus but it’s also often added to fat burners because some research suggests it can improve body composition, although this may only be in elderly folks.(9)(10)
7. Green Tea Extract
The focus here is on EGCG, an antioxidant that appears to affect both fat mass and fat oxidation.(11) A double blind study from the American Journal of Clinical Nutrition, for example, saw a 17 percent increase in fat oxidation with 366mg of EGCGs.(12)(13) Make sure the label specifies the tea’s EGCG content, because some companies just sell capsules of tea leaves.
8. Garcinia Cambogia
This Indonesian fruit gets a lot of hype for some studies, like one published in 2003 in Current Therapeutic Research, that found it may “significantly reduce “ belly fat.(14) This isn’t super well supported just yet, though, and some studies have found it doesn’t really have any effect.(15)
9. Raspberry Ketones
When a study was published in 2010 in Planta Publica that found raspberry ketones reduced body fat among rodents, supplement companies cashed in.(16) But we don’t really have any great human studies and when you correct for body weight, the studies on rodents used amounts much, much larger than what you’d find in any supplement for people.
10. Green Coffee Bean Extract
This one also got a lot of play for the purported effects of chlorogenic acid, one of its components which may inhibit calorie absorption.(17) One of the most popular studies found that chlorogenic acid-enriched coffee resulted in three times more weight lost than a placebo group (5.4kg versus 1.7kg over 12 weeks).(18) Look for at least 120 to 300mg per day.
Remember that fat burners need to be used judiciously and in conjunction with a healthy diet and exercise routine. Before you do make any changes to your diet and exercise routine, be sure to speak with your physician and discuss the merits of adding products like these. Good luck!
1. Achten J, et al. Optimizing fat oxidation through exercise and diet. Nutrition. 2004 Jul-Aug;20(7-8):716-27.
2. Dulloo AG, et al. Normal caffeine consumption: influence on thermogenesis and daily energy expenditure in lean and postobese human volunteers. Am J Clin Nutr. 1989 Jan;49(1):44-50.
3. Ostojic SM. Yohimbine: the effects on body composition and exercise performance in soccer players. Res Sports Med. 2006 Oct-Dec;14(4):289-99.
4. Chaiyata P, et al. Effect of chili pepper (Capsicum frutescens) ingestion on plasma glucose response and metabolic rate in Thai women. J Med Assoc Thai. 2003 Sep;86(9):854-60.
5. Galgani JE, et al. Effect of dihydrocapsiate on resting metabolic rate in humans. Am J Clin Nutr. 2010 Nov;92(5):1089-93.
6. Hoffman JR, et al. Thermogenic effect of an acute ingestion of a weight loss supplement. J Int Soc Sports Nutr. 2009 Jan 6;6:1.
7. Stohs SJ, et al. Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes. Int J Med Sci. 2011 Apr 28;8(4):295-301.
8. Stohs SJ, et al. Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes. Int J Med Sci. 2011 Apr 28;8(4):295-301.
9. Pistone G, et al. Levocarnitine administration in elderly subjects with rapid muscle fatigue: effect on body composition, lipid profile and fatigue. Drugs Aging. 2003;20(10):761-7.
10. Malaguarnera M, et al. Acetyl L-carnitine (ALC) treatment in elderly patients with fatigue. Arch Gerontol Geriatr. 2008 Mar-Apr;46(2):181-90.
11. Hursel R, et al. The effects of green tea on weight loss and weight maintenance: a meta-analysis. Int J Obes (Lond). 2009 Sep;33(9):956-61.
12. Thielecke F, et al. Epigallocatechin-3-gallate and postprandial fat oxidation in overweight/obese male volunteers: a pilot study. Eur J Clin Nutr. 2010 Jul;64(7):704-13.
13. Venables MC, et al. Green tea extract ingestion, fat oxidation, and glucose tolerance in healthy humans. Am J Clin Nutr. 2008 Mar;87(3):778-84.
14. Hayamizu K, et al. Effects of garcinia cambogia (Hydroxycitric Acid) on visceral fat accumulation: a double-blind, randomized, placebo-controlled trial. Curr Ther Res Clin Exp. 2003 Sep;64(8):551-67.
15. Heymsfield SB, et al. Garcinia cambogia (hydroxycitric acid) as a potential antiobesity agent: a randomized controlled trial. JAMA. 1998 Nov 11;280(18):1596-600.
16. Park KS. Raspberry ketone increases both lipolysis and fatty acid oxidation in 3T3-L1 adipocytes. Planta Med. 2010 Oct;76(15):1654-8.
17. Onakpoya I, et al. The use of green coffee extract as a weight loss supplement: a systematic review and meta-analysis of randomised clinical trials. Gastroenterol Res Pract. 2011;2011.
18. Thom E. The effect of chlorogenic acid enriched coffee on glucose absorption in healthy volunteers and its effect on body mass when used long-term in overweight and obese people. J Int Med Res. 2007 Nov-Dec;35(6):900-8.
19. Walsh DE, et al. Effect of glucomannan on obese patients: a clinical study. Int J Obes. 1984;8(4):289-93.
20. Nogara L, et al. Piperine’s mitigation of obesity and diabetes can be explained by its up-regulation of the metabolic rate of resting muscle. Proc Natl Acad Sci U S A. 2016 Nov 15;113(46):13009-13014.
21. Godard MP, et al. Body composition and hormonal adaptations associated with forskolin consumption in overweight and obese men. Obes Res. 2005 Aug;13(8):1335-43.
22. Stohs SJ, et al. Effects of p-synephrine alone and in combination with selected bioflavonoids on resting metabolism, blood pressure, heart rate and self-reported mood changes. Int J Med Sci. 2011 Apr 28;8(4):295-301.
23. Dulloo AG. Ephedrine, xanthines and prostaglandin-inhibitors: actions and interactions in the stimulation of thermogenesis. Int J Obes Relat Metab Disord. 1993 Feb;17 Suppl 1:S35-40.
24. Pittler MH, et al. Chromium picolinate for reducing body weight: meta-analysis of randomized trials.
25. Wiese J, et al. Effect of Opuntia ficus indica on symptoms of the alcohol hangover. Arch Intern Med. 2004 Jun 28;164(12):1334-40.