Best Thermogenic Fat Burners

Written by John Dixon

Fact Checked by: Roger Thomas


PathMed is reader-supported. Our independent research is completed by trained nutritionalists and a team of well informed writers. Our content is then edited and fact checked by our editorial team. When you make a purchase through our links we may earn a commission.

In this article we take a look at the best thermogenic fat burners to help you lose that unwanted body fat.

There are tried and tested ways of losing weight, especially unwanted body fat. The most common, most effective way to lose weight is to eat to a calorie deficit. If you manage a deficit of 500 calories per day (that is, eat 500 fewer calories than your body needs to maintain its current weight) you should end up losing about a pound per week, or half a kilogram. Double the deficit to double the weight loss.

This deficit can come from a mixture of eating less and exercising more (increasing your calorie use).

However, there is often a bit of stubborn fat left behind after a deficit cut. A deficit in itself, though effective, might not always be as efficient as it could be. This is where supplements and other clever tricks can come into play.

Thermogenic fat burning pills represent one such clever solution. They work by producing more heat in the body. This in turn will speed up your metabolic rate and burn more calories. It may even have an appetite suppressing effect – many of the best thermogenic fat burners will include other ingredients to help ward off hunger pangs.

It may sound too good to be true. Sometimes it is – there are a lot of bad supplements out there. However, there are also some fantastic ones, tried and tested, that give you that extra kick when you’re losing weight.

We’ve been through a fair few and found some of the best the market has to offer.

Our Top Thermogenic Fat Burners

We have compiled 8 of the best thermogenic fat burners on the market to help you make a choice that it most likely to have the desired effect.


phenq bottle

PhenQ is one of the best weight loss supplements on the market. We’ve reviewed it a few times, as part of a few lists, and always come away impressed.

There are no side effects to taking it for most people and it’s pretty easy and convenient to take. PhenQ’s formula works around Lacys-Reset, combined with some stalwarts of the thermogenic supplement industry – caffeine, chromium picolinate, L-Carnitine, capsicum, pipeline and niacin, all of which have proven fat burning benefits.

You should see a noticeable spike in your weight loss taking PhenQ, seeing improved fat-burning, reduced fat storage, heightened moods with more energy and mental clarity, and a slightly reduced appetite.

  • Improves energy and mood
  • Fantastic list of ingredients
  • Regularly tops our list of top fat burners
  • Money back guarantee
  • Caffeine may not be appropriate for everyone
  • On the pricey side of things


trimtone bottle

Trimtone is another fully natural, yet incredibly potent, product. They aim it at women, but this is nonsense – it will work well for anyone, as long as they are in a decent calorie deficit and looking after themselves. It does also feature incredibly highly in our fat burners for women review.

You only need one dose per day, making it super convenient, and this should give you lasting energy, higher fat burn, and a feeling of fullness – making it far easier to maintain a calorie deficit.

This fullness comes courtesy of Glucomannan, a principal ingredient that you will see cropping up a lot in weight loss aids – and for very good reason. It is a fantastic type of fiber. Fiber is great for weight loss and dietary health – it expands in the stomach to make you feel fuller for longer, whilst aiding digestive health.

You also get 120mg of caffeine, 100mg of green coffee and 100mg of green tea (both the latter contain caffeine, alongside antioxidants, for plenty of energy). This should give you the energy you need to feel better and keep on going through a calorie deficit.

  • Great for cutting cravings and feeling fuller
  • Impressive caffeine and antioxidant profile
  • Very convenient
  • Anything with caffeine will be unsuitable for some
  • Capsules are not suitable for vegetarians


prime shred fat burner

PrimeShred is another very potent formula mostly aimed at physique competitors and the like, based at least on their branding. It is perfect for those wanting to put in some serious time at the gym, retaining muscle, whilst cutting down their body fat levels.

Each capsule offers a complex of high-potency, natural ingredients, all of which are common in these kinds of products, all in pretty high doses. In fact, PrimeShred bills itself as the most up to date, cutting edge formula for fast, effective fat burning, and the hyperbole isn’t entirely misplaced. All their ingredients are contained in dosages used in the clinical studies on which their work is built.

These ingredients include things like caffeine, green tea, green coffee, DMAE, L-tyrosine, L-theanine, bioperene, cayenne pepper, B vitamins. These all combine to both hit fat hard and give you plenty of energy and antioxidants for peak performance and recovery.

  • A wide range of highly effective ingredients
  • Suitable for vegetarians
  • Perfect for high energy workouts and lifestyles
  • It’s quite expensive
  • Can be unsettling to the stomach at first
  • Caffeine isn’t appropriate for everyone, especially in the quantities offered here


leanbean packaging

Here we have another thermogenic fat burner aimed specifically at women, this time with Leanbean. Don’t pay too much attention to their branding and marketing – Leanbean is a solid product for men and women alike.

As with all thermogenic fat burners worth their salt, Leanbean suppresses the appetite and speeds up the metabolism, hitting your weight loss from both sides. It does this by including caffeine, green tea, green coffee, grains of paradise (a form of ginger which activates brown adipose tissue and increases thermogenesis) and glucomannan, which should give you energy, inspire greater thermogenesis, aid in digestive health, and keep you feeling fuller for longer.

All ingredients are natural and this is another very solid product.

  • Energy boosting and hunger suppressing
  • All natural ingredients with no additives
  • Vegan friendly
  • Gendered marketing – men, don’t pay attention!
  • Again, quite expensive
  • Caffeine content may not be suitable for everyone


phen24 bottles

Phen24 is a clever, two-part supplement. One capsule is for daytime use, with the other for night time. Each pill has different ingredients that have been selected appropriately.

The night time fat burner is designed to optimize night time metabolism while you’re sleeping, whilst the daytime one allows you to be active and have plenty of energy, with a greatly enhanced metabolic rate. Daytime ingredients include stimulants and thermogenesis inducing ingredients. These include caffeine, cayenne pepper, and guarana, alongside micronutrients like zinc, iodine, and copper that are proven to promote energy.

The night time formula includes Glucomannan, for lasting fullness, and ingredients such as ascorbic acid, plyridoxine HDL, chromium and thiamine for metabolism boosting and normalizing results.

  • It’s a clever take on the more traditional thermogenic fat burner
  • Two part system keeps you at an optimum fat burning rate
  • Should normalize blood sugar levels and metabolic rates
  • The daytime capsules contain caffeine, which may be unsuitable for some
  • Less straight forward to take than a once-a-day product

Powher Cut

powher cut for women

Powher Cut is quite a unique dietary supplement. It is very highly caffeinated, with a great blend of natural stimulants, fibers and minerals included. This all works together to keep you working at your peak, with heightened energy levels, even mood, and clear cognition.

It also helps to improve your fat burn by increasing thermogenesis, whilst keeping you fuller for longer with plenty of fiber.

Taken all together, this is a great weight loss tool.

Glucomannan will help you to feel fuller for longer whilst maintaining good digestive health. High caffeine levels will increase your metabolism, even at rest, whilst giving you more energy. The minerals included will add to this, whilst improving your micronutrition intake.

Powher also market solely to women, but Powher Cut works for everyone.

  • Highly stimulating for peak energy levels
  • Ingredients are well tested
  • Optimal doses delivered across the board
  • Great appetite suppressant
  • The high content may make Powher unsuitable for some people

Instant Knockout 

instant knockout bottle

Instant Knockout has some fun branding and packaging. It’s designed for fighters – or at least was conceived in this way – including MMA fighters, martial artists, wrestlers, and boxers. An effective and potent combination of 100% natural ingredients keeps you fighting fit (often literally, if you’re a fan) whilst losing weight rapidly.

As with other products on this list, it contains everything you need to increase energy levels and athletic output whilst increasing thermogenesis effectiveness. Ingredients like caffeine, green tea extract, cayenne pepper, l-theanine, black pepper extract and D- and B- vitamins are sure to keep you on track.

  • Relatively cost effective
  • Very good, natural ingredients
  • Perfect for keeping you fighting fit
  • Very effective for weight loss and energy
  • Shipping isn’t always great from the company
  • High caffeine content may be unsuitable to some
  • A lot of the excitement is just pure, clever branding


phengold for women

PhenGold, created and manufactured by Swiss Research Labs Ltd, is another incredibly effective weight loss supplement which uses all-natural, well-researched, high-quality ingredients to achieve great results. It will improve your metabolic processes and support weight loss incredibly well.

PhenGold mainly aims at the metabolic side of things. It is very potent for boosting thermogenesis, fat burn and energy use. This in turn will lead to greater long term energy and clarity, of course, but this is very much secondary to the improved metabolism.

This said, it includes 150 mg of the nootropic Dimethylaminoethanol for improved brain function and mental clarity, which really sets it apart from anything else on this list. It also includes L-Theanine, which should reduce stress levels.

PhenGold is entirely plant-based, so vegetarian- and vegan-friendly.

  • Very effective metabolic booster
  • Improved mental clarity
  • Fantastic deals on offer from the manufacturer
  • Not much by way of appetite suppression
  • The caffeine may not be suitable for everyone

How To Choose Good Thermogenic Fat Burners?

It is easy to choose a good thermogenic fat burner – simply go with anything from our list above and you’ll be onto a winner!

However, flippancy aside, there are plenty of good weight loss products out there. There are plenty more less scrupulous ones.

Everything will revolve around ingredients and dosing.

There are certain ingredients you want to look out for, most of which we have seen in the products in our list. If a thermogenic fat burner uses any of them – those mentioned above such as l-carnitine, vitamin B6, capsaicin, caffeine, green tea extracts, and cayenne pepper – or any combination of them, you can probably rely on its efficacy. 

If they are there in sufficient quantities – which you can figure out with a quick search on the product page – then go ahead and buy it. You’ve found something good.

What to Avoid in a Thermogenic Fat Burner

Just as there are things you want to look out for in a fat burner, so too are there things to avoid. Again, this will revolve around ingredients and dosing. If something is dosed insufficiently, it won’t be worth the money. If it includes synthetic ingredients, or omits the key ingredients we’ve talked about, you should probably go elsewhere.

Then there are some ingredients you actively want to avoid. They are dangerous and should not be included in any supplement:

  1. Dinitrophenol (DNP) is a heavy hitting metabolism booster that can be fatal. It is also highly illegal, so if you come across a product claiming to contain it, report it to the relevant authorities. Do not be tempted to buy.
  2. Ephedra increases your blood pressure and heart rate as well as helping you to lose weight. Increases to both will put you at risk of chronic conditions such as heart disease and stroke.
  3. M-synephrine also increases blood pressure and heart rate, though less noticeably than ephedra. It can be safe enough by itself but can be very dangerous when combined with stimulants such as caffeine. It can also cross the blood-brain barrier, so you really don’t want to be putting it in your body. It’s also often sold as p-synephrine or o-synephrine, so be careful of these, too.

Thermogenic Fat Burner FAQs

What to Know About Thermogenic Fat Burners?

‘Thermogenesis’ means generation of heat. Thermogenic fat burners are so called because they are designed to speed up the metabolic rate in your body, increasing heat, energy expenditure and fat oxidation. Many are made from all-natural ingredients – we favour these in our list above. 

How Does Thermogenesis Occur?

Thermogenesis rests on a complex biochemistry process within the body. Different supplements and ingredients will elicit it differently, in different ways. However, they will all have the same goal and outcome – they will increase your body’s energy expenditure, which means burning more energy at rest.

What Makes a Good Thermogenic Fat Burner?

There are plenty of fantastic ingredients to choose from when making a fat burner. We have seen all the usual ones above – caffeine, cayenne pepper, glucomannan, grains of paradise, and so on. A good thermogenic fat burner will include a range of these.

Good thermogenic fat burners also don’t need to rely on synthetic ingredients, or those with risky side effects. Everything can be natural with relatively few side effects.

Who Should Use a Thermogenic Fat Burner?

Thermogenic fat burners are useful for anybody looking to lose weight, no matter how active they are. As long as they have a calorie deficit in place and a clear plan of how much weight they want to lose, a thermogenic fat burner should augment the process nicely.

Thermogenic fat burners are generally not safe or appropriate for pregnant or breastfeeding women.

What’s the Recommended Dose for Thermogenic Fat Burners?

Doses will be available in the literature you get with a good thermogenic fat burner. Always read the label and instructions. Some ingredients will be included in higher doses than others – for instance, you might have less caffeine than other ingredients, like green tea or glucomannan. 

Do Thermogenic Fat Burners Have Side Effects?

Yes, there will likely be side effects. Thermogenesis is itself a side effect of taking these supplements. It also leads to other side effects. However, in natural thermogenic fat burners, the side effects shouldn’t be severe or dangerous.

You might get an upset stomach when you first take them. The caffeine content might also give you too much energy, leading to jitters, at the beginning. Always talk to your doctor before changing your supplement regime, especially if you’re on existing medication.

Our Overall Top Choice

There is plenty on offer. Most products are actually quite similar, with a whole host of popular ingredients making it into most formulas in some form. If there is a decent range of any of the usual suspects in a recipe – things like l-carnitine, vitamin B6, capsaicin, caffeine, green tea extracts, and cayenne pepper – then you have a winner.

However, there is always a top spot. For us, that’s PhenQ. It’s the best all-rounder, giving you everything you need to feel less hungry and more energetic, and to ensure that your body works through fat as optimally as possible.

PhenQ also rests on far more scientific evidence than most supplements: there really are few that are so well-researched and so driven by the data and science. You are in truly safe hands with it.