Our Opinion on Protein Works Thermopro Burn (Updated)

A photo of fire crackling at night representing the theme of the article titled ThermoPro Burn Review.
Photo by Miriam Espacio


  • Natural formula
  • Good selection of thermogenic ingredients
  • Caffeine gives an energy kick
  • Might help you lose some weight if you’re consistent in the long run
  • Costing $11.35 per bottle of 90 capsules (price can be higher depending on discounts)


  • Stimulant combination creates an illusion that it works better than it really does
  • Potential side effect risk from combining bitter orange+caffeine
  • Missing some core ingredients
  • Some unproven ingredients wasting capsule space
  • Green coffee extract, cayenne pepper, white kidney bean, and other key players are underdosed


Is Thermopro Burn by Protein Works a good weight loss supplement? If you’re on a budget, it’s a solid pick. Thanks to the stimulants caffeine and bitter orange, you should experience a lift in your energy levels and mood. This will also result in an increased metabolic activity. There’s also l-tyrosine in Thermopro Burn which helps to boost mental focus.

Now, is Thermopro Burn the best fat burner we’ve seen? We wouldn’t go that far. You get what you pay for here. Lack of key appetite suppressants like glucomannan and 5-HTP, along with some unproven and/or underdosed compounds in Thermopro Burn drag it behind the most effective weight loss formulas on the market. Obviously, those are also more expensive. If ThermoPro Burn is your budget limit, it’s worth trying—it could give you decent weight loss results.

What do we recommend?

>Top 5 Fat Burners of This Year<

What is Thermopro Burn?

Thermopro Burn is a natural performance supplement that contains 15 different ingredients. Produced by the U.K. company Protein Works,Thermopro fat burner is said to be a 2-in-1 kind of supplement – a pre-workout and a fat burner.

On one hand, Thermopro Burn can boost your mental & physical performance by reducing fatigue and boosting energy production. On the other hand, it helps with your calorie-controlled diet by boosting your metabolism.

Thermopro burn is officially available on Protein Works’ website, but some third-party websites also sell it. The product is available in multiple countries including in the USA, UK, and Pakistan.

The questions we aim to answer in-depth today is, does Thermopro Burn really work, and what do studies say about its ingredients? How safe it is to use?

See for yourself:

How to Use Thermopro Burn

1 to 3 capsules daily. Because of the potent nature of Thermopro™ it’s important to assess your tolerance first, so we advise starting with 1 capsule daily before training and then progress from there if required. More experienced users may take 3 capsules before training or spaced evenly throughout the day. 

WARNING: Before supplementing with Thermopro™ consult with a medical professional since the formula is VERY POTENT. Do NOT use if you are pregnant or prone to dehydration and stop or reduce the dosage if sleeplessness, tremors, dizziness, nervousness, headaches or heart palpitations occur. Thermopro™ was purposely created as a powerful, stimulant that should only be taken by healthy adults, aged 18-50 years old to help break training plateaus.

Contains caffeine. Not recommended for children or pregnant women’ in accordance with Article 13(1) of Regulation (EU) No 1169/2011, 156mg/1pill – 468mg/3 pills.

Thermopro Burn: The Ingredients

Here are the ingredients in Thermopro Burn;

  • Vitamin B12 – 200mcg
  • Biotin – 200mcg
  • Vitamin B5 – 6mg
  • Chromium – 60mcg
  • L-Tyrosine – 200mg
  • Caffeine – 150mg
  • N-Acetyl-L-Carnitine – 100mg
  • Bitter Orange Peel – 100mg
  • Green Tea Extract – 50mg
  • L-Phenylalanine – 25mg
  • White Kidney Bean Extract – 24mg
  • Cayenne Powder – 5mg
  • Green Coffee Extract – 4mg
  • Guarana Extract – 1.8mg
  • Black Pepper Extract – 1mg

As shown on the label:

At first glance, the formula of Thermopro Burn looks good. There are quite a few basic vitamins (B5, biotin) in the supplement, but also some well-known fat-burning plants such as green tea extract and guarana extract.

What’s more, the ingredient label of Thermopro Burn by Protein Works is completely transparent; meaning, we can clearly assess the dosages of each ingredient for safety and effectiveness.

Let’s take a closer look.

B-Complex Vitamins

Thermopro Burn contains 3 different B vitamins – B5, Biotin, and B12. All of the B vitamins are essential for our body, which means we need to obtain them through our diet as our body can’t make them on its own. Alternatively, you can also supplement with B vitamins if your diet doesn’t supply adequate amounts.

When you’re deficient in B vitamins like B12 and B5, you may experience a lack of energy and focus during the day. A lack of some B vitamins can also contribute to slower metabolic function and poor blood sugar regulation, which translates to weight gain.

Luckily, most of us already get plenty of B vitamins through our diet, as most foods contain them. The only groups of people who can be potentially deficient are the elderly, those with genetic disorders, and strict vegans.

In other words, unless you’re deficient (which is unlikely), you probably won’t experience any notable benefits from the B-complex vitamins in Thermopro Burn.

Chromium – 60mcg

Chromium is a trace mineral that our body needs for many things, one of which is blood sugar regulation. When your blood sugar levels stay more stable, so do your energy levels throughout the day. By extension, you will be more focused and have fewer sugar cravings. This makes chromium one of our favorite ingredients in fat burners – it doesn’t really help you burn fat, but it contributes to the prevention of extra weight gain.

L-Tyrosine – 200mg

L-tyrosine is a non-essential amino acid, which means you don’t need to get it from food. Among its functions, l-tyrosine acts as building blocks for neurotransmitters in your brain, called “catecholamines.” The three catecholamines are dopamine, epinephrine (adrenaline), and norepinephrine (noradrenaline).

By supplying your brain with the raw materials to synthesize these neurotransmitters, l-tyrosine can help your brain work better – more specifically, it assists in elevating your focus, tolerance to stress, and social functioning. Especially during stressful situations.

It is an all-around useful nutrient to supplement, even though it doesn’t have any weight loss benefits per se.

Caffeine – 150mg

Most of us are familiar with caffeine in one form or another, whether that’s coffee, an energy drink, tea, or dark chocolate – these are all good sources. Many of us love caffeine because of how it makes us feel – boosting our focus, concentration, energy levels, and mental & physical performance.

But did you know that caffeine is also a natural fat burner? It does this by amping up your adrenaline and noradrenaline production. These two are stress hormones that, when elevated, raise your metabolic rate. In turn, your body starts burning more calories and breaking down stored fat cells in the body more easily.

N-Acetyl-L-Carnitine – 100mg

L-carnitine is a semi-conditional amino acid. It has been shown to be helpful for liver diseases and brain function among others. However, despite the hype, the claims that l-carnitine is an effective fat burner are not fully supported by evidence. Even in the studies that found some beneficial effects, l-carnitine was in many cases too weak to produce substantial weight loss.

Still, this doesn’t mean that carnitine is a useless supplement. Especially since it comes with the “N-Acetyl” part in its name, which is the form of carnitine that can easily enter your brain. There, it assists in energy production in your cells (specifically, your mitochondria).

Our body makes some l-carnitine on its own, so supplementation is often unnecessary. However, there are some cases such as hard weight training, where muscles get depleted of l-carnitine, where supplementation can help replenish it more quickly. And therefore contribute to faster muscle recovery.

But, again, if we’re talking about fat burning specifically, l-carnitine is not on the list of the best ingredients you should look for. Far from it!

Bitter Orange Peel – 100mg

Judging by its name alone, Bitter Orange Peel can sound like a harmless natural compound. It really is not!

Bitter orange peel contains the active compound “Synephrine,” a stimulant that is similar in structure and effects to the banned substance “Ephedra”.

Synephrine from bitter orange is known to elevate blood pressure, increase blood circulation, and boost energy levels.

Due to its harsh effects, you’ll often hear of people getting negative reactions from Bitter Orange Peel. Let alone when you combine it with other stimulants like caffeine (more on that in the side effects section). It is not the best choice for a fat burner in our opinion. There are safer and more effective natural ingredients out there.

If you have a condition, please check with your MD before ingesting bitter orange.

Green Tea Extract – 50mg

Green tea extract is a fantastic choice. Green tea is full of EGCG, an antioxidant that is studied for its general health and weight loss benefits. It works by boosting thermogenesis, your body’s natural metabolic process – resulting in more calories being burned.

Green tea is also a fairly safe ingredient. It contains very little caffeine so unless you’re sensitive to stimulants in general, it shouldn’t cause you side effects.

There is one issue here, though – its dosage. 50mg per serving is in our opinion too low for effective fat burning. If you want the best effects, you should aim to take at least 200mg of green tea extract. Some of the market-leading fat burners use around 400mg per serving.

L-Phenylalanine – 25mg

Phenylalanine is an essential molecule that your body needs to get from foods such as bananas, dairy, and meat. It is similar to l-tyrosine in the sense that it is being used by your brain to produce dopamine – a chemical that affects your focus, mood, and energy levels.

White Kidney Bean Extract – 24mg

White Kidney Bean is another good choice. This ingredient is rich in certain compounds which slow down the absorption of foods in your intestines, which helps with mood swings, blood sugar spikes, and consequently – weight regulation.

Cayenne Powder – 5mg

Cayenne pepper might sound like a weird compound to add to a fat burner. However, when you look at its properties, it’s clear cayenne is one of the best natural fat burners on the market.

Cayenne pepper contains the key compound capsaicin, which heats your core body temperature. In order for your body to regulate its temperature back to normal, it has to burn more calories – which ultimately contributes to weight loss.

Green Coffee Extract – 4mg

Don’t worry, this isn’t yet another source of caffeine in Thermopro Burn! Green coffee bean is just what the name implies – a raw coffee bean in its unroasted state. This type of coffee bean is extremely low in caffeine but high in chlorogenic acid, which is a compound that is known to reduce sugar cravings.

Guarana Extract – 1.8mg

We usually wouldn’t be too happy about guarana here, due to the fact that it is a potent source of caffeine when you already have too many stimulants in the supplement. But, due to its extremely low dose of 1.8mg in Thermopro Burn, guarana won’t do much for you here. Neither in terms of energy, no fat loss!

Black Pepper Extract – 1mg

Black pepper extract is included in Thermopro Burn not because it has much of a weight loss effect – it doesn’t – but because it assists in the digestion, absorption, and utilization of other ingredients. Black pepper extract is a good choice in most cases, we’re just not sure if bitter orange peel and caffeine need to be any stronger than they already are! Probably not.

Our Thoughts on the Ingredient Profile

Thermopro Burn is a decent ingredient profile. It has a few ingredients that have the potential to increase your metabolism and help you lose some weight in the long run. More so if you combine it with a calorie-controlled diet and a disciplined exercise regimen.

That said, Thermopro Burn might not be the safest fat burner we’ve reviewed. It has Bitter orange+multiple sources of caffeine which are responsible for its energizing effect. But this might be too much for people sensitive to stimulants.

While Thermopro Burn can be a decent option for those looking for a stimulant pill, there are definitely more effective and safer fat burners available on the market.

Editor’s Pick:

The Five of the Best Fat Burners of 2024

Customer Reviews

We haven’t been able to find independent/impartial Thermopro Burn reviews online due to the product being officially available only on its website, where it has a near-perfect score.

Does Thermopro Burn Have Side Effects?

Thermopro Burn is a product that contains bitter orange peel, a stimulant known to cause a variety of negative side effects. When combined with other stimulants like caffeine, the risk obviously increases. Some potential side effects people sensitive to stimulants can experience from Thermopro Burn include:

  • Energy crash after the effects wear off
  • Nausea
  • Diarrhea
  • Anxiety
  • Insomnia
  • Heart palpitations
  • Elevated blood pressure

For those who tolerate stimulant compounds well, Thermopro by Protein Works shouldn’t be causing any problems.

Thermopro Burn Review Summary

Thermopro by Protein Works is a fat burner that does work, but it also comes with the risk of potential side effects.

So, is it the right product for you? At the end of the day, it depends on whether you’re OK with stimulants or not.

If you are an experienced user of pre-workout or fat burner supplements, then Thermopro Burn should be fine for you. The combination of caffeine, Bitter Orange, Green Tea Extract, and Cayenne Pepper should give you a metabolic boost where you will experience some weight loss if you’re consistent over the long term.

But is Thermopro fat burner the safest and most effective weight loss supplement out there? We don’t see it that way. It is possible to get safe and good results without relying on the controversial Bitter Orange Peel. Instead, Thermopro Burn could’ve included a natural appetite suppressant like glucomannan which would potentially make the supplement more effective at curbing appetite and combating food cravings.

It is cheap, though, so if you aren’t looking for anything better at the moment, it’s hard to argue against Thermopro Burn. For our current recommended alternatives, see the link below:

-Click for Top 5 Fat Burners of This Year-

Further reading:

1 Comment

  1. Hi I just got a tub of thermopro as a gift with an order. I’ve never taken any fat burners. I train 3 to 4 times a week a mix of cardio and strength I’m currently trying to cut weight (post pandemic) yes thats still my excuse lol I’m going to stick to my normal training schedule and only has 45 capsules of which I will take 1 a day. I’d be happy to provide an update over the usage period I notice you said in the article you’ve had trouble finding impartial reviews.

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