Best Thermogenic Pre-Workout For 2021

Just when you thought the fitness supplement industry couldn’t get any more confusing, a whole new product sub-category emerges onto the scene.

The Thermogenic Pre Workout is a hybrid of the Thermogenic Fat Burner and the Pre Workout.

It is designed to provide performance-enhancing benefits while, at the same time, ramping up your fat burning ability.

In A Hurry? Here our the best thermogenic pre workouts:



Lean Pre-Workout
  • Exceptional “cutting” pre-workout
  • 100% formula transparency
  • No dyes/additives
View on Transparent Labs


Nitrosurge Shred – Thermogenic Pre-Workout Supplement
  • Energy boost
  • Thermogenic effect
  • Multiple Flavors
View on Amazon


RAW Synergies Pre Workout Thermogenic Fat burner
  • All Natural Ingredients
  • Thermogenic effect
  • Enhances Training Energy
View on Amazon


Cellucor C4 Ripped Pre Workout
  • 150mg of Caffeine
  • Sugar Free
  • 2 Flavors from a popular brand
View on Amazon


DeFine8 Fat Burner Pre-Workout Thermogenic
  • Crash Free Boost
  • More Sustained Energy
  • Improves focus
View on Amazon

In this article, we answer the questions you need to know to get the best results from a thermogenic pre workout.

What is a Thermogenic Pre-Workout?

A thermogenic fat burner is designed to speed up the metabolism by raising your body temperature.

In doing so, it creates an environment in your body that is conducive to fat burning.
It does this with the aid of natural stimulants such as caffeine, green tea extract, and guarana.

Thermogenic fat burners boost your metabolism 24/7 while also making your workout more productive.

A good thermogenic will also address your appetite.

It will work on the satiety centers in the brain that help to keep your appetite checked.

Thermogenesis: What exactly is it?

Simply put, thermogenesis refers to the production of heat or, in the case of humans (and other animals) the “burning” of calories (which is more accurately the burning of the energy we produce through nutrient breakdown) as a result of fueling our metabolic processes.

Thermogenesis and Fat Loss

I’m sure you’ve all heard of “calorie burning to lose weight / fat” but the truth is, is that we’re always burning calories, whether we’re gaining or losing weight / fat.

Our body is like this amazing organic machine which is constantly producing, using and storing energy.

How we lose fat is if the amount of energy we’ve used that day is greater than the amount of energy we’ve stored.

This means our body will have to break down existing stores of nutrients / other structures, to metabolize and use for energy.

This situation is what is popularly known as a calorie deficit, and it is the singular determinant of weight loss.

lean muscles

Regular vs Thermogenic Pre-Workouts

The pre-workouts you may be accustomed to are flooded with ingredients aimed at improving performance; from delaying fatigue to improving maximal strength, buffering lactic acid and even increasing concentration. Ingredients like creatine, beta-alanine, betaine, tryptophan and more will be ever present in the more popular, performance enhancement focused pre-workouts.

Thermogenic pre-workouts however have been designed in mind to optimize thermogenesis and energy expenditure both during and long after the workout has ended.

An examination of the label will reveal a whole host of different ingredients, including; green tea extract, conjugated linolenic acid (CLA), capsaicin, l-carnitine and capsicum/cayenne (to name a few of the key, most researched, components of thermogenic pre-workouts).

Can Fat Burners Be Used as Pre workouts for Fat Loss?


Thermogenic Pre Workouts combine the effects of a thermogenic fat burner with those of a pre workout supplement.

They are designed to provide you with more energy, strength and focus for your workout while also speeding up your metabolism during the workout and in the hours after you leave the gym.

According to a study published in the International Journal of Obesity in 2005, thermogenic ingredients can boost fat burning potential by 10-15 percent (1).

What is the Difference Between Fat Burning Pre-Workouts and Fat burner Pills?

Quality and caffeine content most often. Fat burning pills tend to be much higher in caffeine and provide token dosages of other thermogenics simply to have them on the label.

The pre-workout powders, whilst usually more expensive, tend to be of much higher quality and offer greater benefit. It should also be worth noting that caffeine is a relatively cheap ingredient, and so companies selling pills / capsules that are loaded with caffeine for higher prices are achieving a huge mark up and effectively scamming you out of money (whilst typically over-promising on effectiveness).

Benefits of a Thermogenic Pre Workout

• Boosts metabolism to increase calorie burn 24/7
• Increased energy
• Improved focus
• Appetite suppressant
• Improves your workout performance

Key Ingredients to Look for in a Thermogenic Pre Workout


Caffeine is the world’s most widely consumed stimulant.

Studies have shown that it has the ability to speed up the metabolic rate by 8-11 per cent over a 12-hour period.

It also stimulates the production of adrenaline.

Caffeine also has the ability to boost the level of fatty acids in the blood, making them more readily available for energy (3).

Green Tea Extract

Green Tea Extract is an extract of green tea leaves.

It contains antioxidants mainly in the form of green tea polyphenols and catechins as well as caffeine, all of which are believed to aid fat loss by inducing thermogenesis, stimulating fat oxidation and increasing metabolism (4) (5).

Conjugated Linoleic Acid

Conjugated Linoleic Acid (CLA) is a fatty acid, primarily found in beef and dairy products, that has been shown to promote long-term fat reduction and health management.

Lab and clinical studies have also revealed that CLA promotes muscle tone as well as reducing cholesterol levels and boosting metabolism (6).


Capsaicin, an active ingredient in hot chili, increases core body temperature by boosting adrenaline levels.

It has been shown to increase workout calorie burn while also minimizing the effect of the body’s adaptive response to calorie reduction (7).


L-Carnitine is synthesized in the body from two dietary essential amino acids. It plays an incredibly important role in the transportation of fatty acids into the cell to be used as energy.

Acting as a “shuttle” for fatty acids, it transports them to the energy production centre of the cell, the mitochondria, where they can be broken down and used to produce energy.

Collective research investigating the available data on L-carnitine provision has shown that it does appear to have a significantly beneficial effect on weight / fat loss (possibly by reducing fatigue and increasing energy expenditure).

Capsicum / Cayenne

Capsicum refers to the entire family of peppers, including cayenne, which may have other unique compounds aside from capsaicin which can aid in weight / fat loss.

One such compound, dihydrocapsiate, has shown the potential to increase metabolic rate.

The “spicy” component of these foods (specifically when we look at the chilli group within the capsicum family) may also boost weight / fat loss progress by increasing our body temperature. Having a concentrated extract within a thermogenic pre-workout may simply add the “cherry on top” to our weight / fat loss campaign, and really help attack it from all angles.

How Do Thermogenic Supplements Work?

Whilst the term thermogenic would suggest these supplements simply work by increasing our energy expenditure through heat, that would actually be a disservice to the multi-factorial way in which they can promote even greater losses in weight and body fat.

They will of course increase lead to the increase in energy expenditure via the mechanisms we’ve alluded too but they can also increase energy expenditure thanks to the stimulatory effect associated with their use. This stimulatory effect can lead to greater amounts of energy expended through activity, namely exercise and during your workouts.

This will continue after the fact as well, and effect your activity throughout the rest of the day causing it to remain elevated above what is your atypical level of activity. We call this NEAT (non-exercise activity thermogenesis), and it includes energy expended through all other forms of activity outside of programmed exercise (such as fidgeting). It’s actually believed that changes in NEAT determine the ultimate successfulness of weight / fat loss and maintenance thereafter.

One final function worth mentioning, is how these supplements not only affect our expenditure but also our energy intake. Acting as appetite suppressants and regulators of blood sugar and fatigue, they can help curb hunger and appetite, ultimately lowering how many calories (from food) you take in. Eating less is arguably the easiest way to achieve a calorie deficit, and if we can do that we will then successfully achieve weight / fat loss.

Best Time to Take It

For best results, you should take your thermogenic pre workout 30 minutes before your workout.

On no workout days, take it 30 minutes after waking up to produce an all day long metabolic increase.

Thermogenic pre workouts normally come as either a tablet, capsule or powder.

The stimulatory effects of these supplements mean that you shouldn’t take them within 5 hours of going to bed.

Thermogenic pre workouts should be cycled in order to prevent the body from developing a tolerance to the ingredients.

After using them for 8-10 weeks, take a 6-week break before cycling for a further 8-10 weeks.

How to get the best results

The key determinants of how successful your thermogenic pre-workout cycle will be your diet and maintaining your exercise routine.

Ensuring you’re in a calorie deficit is critical, and whilst thermogenic supplements will make that task easier, your diet will often determine if you are or if you aren’t achieving that goal.

A higher protein diet has been shown to be one of the most effective tools for weight / fat loss and subsequent maintenance, as is an increase in fibre and fruit and vegetable intake.

The consistency of your exercise routine may be more important than the intensity too; there’s little value in doing “extreme” workouts for two to three days and then not being able to move for a week (as this will also severely affect your NEAT).

Stick to weight-based training when you can (to retain as much lean muscle mass as possible), shortening rest times between sets to keep your heart rate elevated and practice some low-intensity activities on your rest days (walking is a great choice, and extremely therapeutic too!).

Are There Any Side Effects?

Thermogenic pre workouts carry two key side effects:

• Dehydration
• Lack of Sleep

Because thermogenics increase the body’s core temperature, the body needs more water in order to maintain its ideal body temp.

For this reason, you should drink more water when supplementing with a thermogenic.

The increased energy produced by the stimulants in thermogenics can affect sleep if taken within 5 hours of going to bed.

Stimulants such as caffeine may produce unwanted effects such as the jitters, headaches and a post-exercise energy crash if taken in large doses.

For this reason, you should not go beyond 400mg of caffeine per dose.

Thermogenic Pre-Workout cycles

There is an argument to be had that you should “cycle” on and off thermogenic pre-workout supplements to get the most benefit from their usage.

The effectiveness of caffeine, as well as components within peppers, appear to diminish over time, requiring a greater dose. This is due to the build up of tolerance towards that given ingredient, however increasing the dose would not be recommended as that could be potentially quite dangerous (especially with caffeine).

Going “cold turkey” may not be the best approach however (with caffeine withdrawal actually being reclassified as a mental health disorder), and reducing intake progressively before halting altogether for a period of several weeks and then reintroducing will likely ensure that you keep your sanity whilst getting the most out of your supplements.

Top Thermogenic Pre-Workout Supplements

Transparent Labs PreSeries LEAN

  • Exceptional Cutting Pre-Workout
  • 100% formula transparency
  • No dyes or additives
Lean Pre-workout supplement from Transparent Labs

PreSeries Lean is a thermogenic fat burner that is designed to maximize your fat burning, provide clean energy, and start the recovery process after training.

With 21 active ingredients clinically dosed, this pre workout was built for results.

However, it does provide a significant fat burning effect, while also noticeably increasing training energy.

The recommended dosage is 1 scoop (16.14g) before training.


  • Fat burner
  • Thyroid support complex
  • Clinically dosed
  • 30 serving supply


  • Higher sticker price
  • No creatine

Nitrosurge Shred Thermogenic Pre Workout Supplement

  • Energy boost
  • Thermogenic effect
  • Multiple flavors
nitrosurge shred thermogenic pre-workout supplement

Nitrosurge Shred is an all natural thermogenic fat burner that is designed to promote energy and power output while working out.

It contains some solid fat burning ingredients including:

  • Caffeine Anhydrous
  • L-Citrulline
  • Acetyl-L-Carnitine
  • Beta-Alanine
  • L-Theanine
  • Hordenine HCI
  • Synephrine HCI
  • BioPerine

Citrulline is an amino acid which enhances endurance by being converted to L-Arginine in order to increase the nitric oxide levels in the body.

This increases the blood supply to muscle cells, increasing the pump effect and boosting endurance.

The Carnitine in Nitrosurge improves training energy and focus while, in conjunction with caffeine anhydrous, also boosting the metabolism.

Bioperine is a black pepper based ingredient that helps with absorption to get the ingredients into your system sooner.

There are a number of side effects associated with the ingredients in Nitrosurge.

Beta-Alanine can produce an itching effect in the hands and face which is known as paresthesia.

Synephrine has been known to cause headaches, dizziness and elevated blood pressure.

The recommended dosage of Nitrosurge is 1 serving (1 scoop) with 6 – 8 oz of water 30 to 40 minutes before your workout. Do not exceed 2 scoops in a 24hour period.


• Energy boost
• Thermogenic effect


• Beta-alanine may cause a tickling sensation on the skin
• Citrulline under dosed at 2 grams (should be 6-8 grams per serve)

RAW Thermo Pre

  • All Natural Ingredients
  • Thermogenic effect
  • Enhances Training Energy
RAW Pre-workout supplement powder

ThermoPre is a 2-in-1 preworkout thermogenic designed for men and women. The brand may cater more to women but this product is fine for both genders.

It includes no artificial sweeteners, dyes or hyper stimulants. Instead, it contains:

  • Organic Stevia Leaf Extract
  • Citric Acid
  • Sicila
  • Beet Root
  • Ashwagandha
  • Coffea arabica bean
  • Yerba Mate
  • Beta Alanine
  • Acetyl-L-Carnitine

These ingredients provide an effective and safe, yet potent, thermogenic boost to speed up the metabolism.

At the same time, they deliver a sustained, clean flow of workout energy that will not be followed by a stimulant crash.

This product also has a nootropic effect, to focus the mind and provide greater training focus.

The only potential side effects with this product come from the beta-alanine, which may cause itchiness in the hands and feet.


  • All-natural ingredients
  • No fillers
  • Thermogenic effect
  • Enhances training energy
  • Nootropic Benefits


  • Beta-alanine may cause itchiness in the hands and feet

Cellucor C4 Ripped Pre Workout

  • 150mg of Caffeine
  • Sugar Free
  • 2 Flavors from a popular brand
Cellucor C4 Ripped Pre-Workout supplement

Cellucor C4 Ripped is a pre workout that combines proven energy and power boosting ingredients with those that are specific to fat loss.

This is a creatine free pre-workout that delivers a proprietary blend of the following compounds:

  • L-Carnitine
  • Green Coffee Bean Extract
  • Cayenne Fruit Extract
  • Coleus Forksohlii Root Extract

Each serving of Cellucor C4 Ripped also contains 1.6 grams of Beta-Alanine to enhance your training pump, 150 mg of caffeine for energy and 1 gram of Arginine AKG for endurance.

Cellucor C4 Ripped comes as a pre-workout powder.

It should be taken 30-45 minutes before your workout.

The recommendation is to start with one scoop in a glass of water and increase to two scoops once you have gotten used to the product.

Some people have reported a tingly sensation when taking two scoops, so we suggest cutting back to 1.5 scoops per day with water.


  • Energy enhancer
  • Thermogenic effect
  • Enhanced training pump


  • May produce slight tingly sensation

DeFine8 Fat Burner Pre-Workout Thermogenic

  • Crash Free Boost
  • More Sustained Energy
  • Improves focus
DeFine8 fat burner pre-workout supplement

DeFine8 is a powdered thermogenic that delivers a smooth flow of training energy without the crash that comes with heavy stimulant based products.

In addition, it provides you with the equivalent of 25 cups of green tea in each scoop to provide a potent fat burning effect.

DeFine8 is calorie, sugar, and carb free.

Each scoop delivers 80mg of Vitamin B6, 500mg of B12 and a 1545mg proprietary blend made up of the following:

  • Green Tea Extract
  • Coriander extract
  • Bittermelon extract
  • Caffeine anhydrous
  • Cocoa extract

DeFine8 comes in 10 tasty flavors. It mixes well and absorbs quickly. The caffeine in this product comes from guarana.

This form of caffeine is released more slowly into the body to provide a sustained energy source.

Guarana has also been shown to be an effective appetite suppressant.

DeFine8 should be taken in the morning and again just before your workout.


  • Crash free energy boost
  • More sustained energy
  • Improves focus
  • Appetite suppressant


  • Contains Dandelion extract which may act as a diuretic

Stacking Supplements with a Thermogenic Pre-Workout

Which supplements you stack with your thermogenic should be in direct relation to your goals. One thing we would say however is do not be tempted to stack another stimulatory supplement alongside your pre-workout; this is a sure-fire way to develop an immediate (and possibly very dangerous) health issue.

There are several additional supplements related to weight / fat loss that may be worth adding to your stack (if not already found within the pre-workout).

African mango, or Irvingia gabonensis, is a fruit-bearing tree that is native to western and central Africa. Irvingia gabonensis seed kernel extract has been proposed to promote weight loss by inhibiting adipogenesis (the creation of new fat cells) whilst also reducing levels of leptin (the hunger hormone).

Chromium is an essential trace mineral which can help regulate blood sugar levels. Large scale review studies have shown chromium to be of benefit in those looking to lose weight and body fat. Whilst the affect isn’t practically huge, every little count with weight / fat loss and having one further additional contributor (which is safe in the dosages used in these studies; 137 to 1000mcg a day for up to half a year) could round out your weight / fat loss “puzzle”.

One other compound worth mentioning (trust us, there are way, way more, but most have very little to no human evidence to support their use) is Garcinia cambogia. It is a fruit-bearing tree that grows throughout Asia, Africa, and the Polynesian islands and contains compounds proposed to inhibit lipogenesis, suppress food intake, and reduce weight gain.

Other supplements you could consider stacking would be those mentioned in relation to performance enhancement; creatine, beta-alanine, betaine etc. The added performance benefit and enhancement may confer in great energy expenditure through increased activity, increased effort or even greater resting metabolic rate (thanks to increasing in lean muscle mass).

A final nod should be directed towards electrolyte supplementation. Many of the thermogenic pre-workouts will act as diuretics and so having an electrolyte may help stave off any nasty cramps and or decreases in exercise / general performance. You could alternatively increase your dietary intake of electrolytes; bananas, watermelons, beans and nuts are all great sources!

Thermogenic Supplement FAQs

  • Should I Take a Thermogenic?

Whilst they are definitely not a necessity they may benefit. More experienced trainers / dieters may see the benefit over those with less experience.

  • Are Thermogenics Dangerous?

This depends entirely on how they are used. There are obvious side effects to consider (dehydration for example) however sticking to recommended dosages should make them relatively say. Exceeding the dosage carries risk however and even before using you should consider speaking with your respective healthcare professional (as you should do when considering the use of any stimulant containing products).

  • Should You take Thermogenics Before Working Out?

This would be optimal as they will help to increase energy expenditure both during and after your workout (as well as possibly promoting increased recovery). You may also consider taking them on non-training days to help keep your NEAT elevated, however consider lowering the dosage if you don’t feel you need the whole amount.

  • Do Thermogenics really work?

Whilst we can’t say definitively yes for all products (as some brands produce much higher quality products than others) they will, in principle, be of benefit.

  • Do Thermogenics give you energy?

Those containing stimulatory ingredients, such as caffeine and caffeine like compounds (guarana for example), will give you a sense of increased “energy”.

  • Can Pre-workout help lose weight?

They can help of course, but certainly won’t make up for poor dietary practices and or lack of exercise. They are the “cherry on top”, not the whole cupcake.

  • Are all fat burners thermogenic?

Not necessarily. Many of these products benefit function in other ways, such as inhibiting the creation of fat cells, improving satiety, improving exercise performance etc.

  • Is Taking More Thermogenics better?

No, in fact, it may be dangerous. Always stick to the recommended dosages and don’t be tempted to double up on various products hoping to get twice the benefit; you’ll likely just land yourself a hospital visit.


Thermogenic Pre Workouts provide you with the double-whammy of enhanced fat burn and greater workout intensity.

The best product in our round up review is DeFine8 from MuscleWerks.

DeFine 8 does not come loaded down with the stimulant side effects that are common with many thermogenics.

Instead, it delivers a clean, sustained energy flow to power you through your workouts.

At the same time, it will boost your metabolism for a 24 -hour fat burn along with an appetite suppressant effect.

To top it off, you have your choice of 10 delicious flavors.

The thermogenic pre workout market is set to become the next big thing in the supplement industry.

Here are the keys points to remember when negotiating your way through the market:

  • Look for a product that provides clean energy and enhanced metabolism
  • Avoid artificial flavors and fillers
  • Avoid proprietary blends
  • Look for these key ingredients:
    • Caffeine
    • Green Tea Extract
    • Capsaicin
    • Conjugated Linoleic Acid