Ex-Martial artist and PT James Dixon puts this thermogenic fat burner to the test in our Instant Knockout review. Find out how he got on with it years ago and if he still rates it today after his latest round of testing…

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Weight loss can be hard. The deck often feels stacked against us. Even if you get your diet plan and lifestyle streamlined for weight loss (which you need to do as your main priority if you’re looking to shed body fat), there are numerous challenges that can get in the way.

A weight loss regime can affect your mental wellbeing, including your mood, anxiety, and energy levels, as well as often negatively impacting your metabolic health.

This is where fat burners come into play. They aren’t magic pills. They aren’t designed to cause your body to lose weight no matter what. What they do is simply undo many of the negative side effects of living in a calorie deficit whilst making your weight loss journey as a whole more manageable and more efficient.

There are some fantastic products out there, too, some genuinely brilliant fat burners. We’re going to look at one of these today, in the form of Instant Knockout Cut, one of the best, most potent fat burners on the market for those looking to live an active lifestyle.

Quick Verdict: Instant Knockout

instant knockout package
Instant Knockout is one of the best thermogenic fat burners on the market. It isn’t for the faint hearted. The energy boost you get from its caffeine content is intense. This can be great for some. It can unhealthy for others. However, if it works for you, you’re in for a real treat.

The formula is packed full of intelligently combined ingredients all included to aid your weight loss efforts in multiple different ways. It will, of course, give you a big energy boost. This includes overcoming much of the brain fog and lethargy associated with undereating. It will also elicit greater rates of thermogenesis. It works as a wonderful appetite suppressant and fibre source, making a calorie deficit easier to maintain and healthier to keep up.

In short, it ably mitigates many of the side effects associated with a calorie deficit, whilst making that calorie deficit easier to maintain and more effective.

About Instant Knockout

Instant Knockout isn’t for the faint hearted. It’s designed for those who want to go full throttle. In fact, it doubles up nicely as a potent pre-workout supplement – it’s full to the brim with stimulants and ingredients aimed to give you a massive energy kick.

girl using instant knockout cut

The creators, Roar Ambition (one of my favourite supplement companies), have put it together with high-powered workouts and optimal athleticism in mind, making it perfect for those who don’t want to sacrifice physical output during their weight loss journey.

Instant Knockout is somewhat erroneously targeted at fighters – MMA competitors, boxers, martial artists, etc. The packaging makes this quite obvious.

The bottle is, after all, a clenched fist! I don’t call this erroneous because it’s no good for them.

Quite the opposite.

It’s perfect for anybody looking to put a good session in on the heavy bag or go five rounds without letting up. Everything included in its formula is there to give fighters the edge.

Rather, I call it erroneous because this seems somewhat limiting. You don’t need to be a martial artist to benefit from it. Far from it. If you live an active lifestyle and want to keep it up as you enter a calorie deficit, during which you are literally denying your body sufficient energy, you will benefit from using Instant Knockout.

instant knockout package

Swimmers, sprinters, footballers, gym-rats, strength athletes, HIIT fanatics, and many more will make good use of it, as long as their training is on the explosive side.

As we will see, Instant Knockout delivers on its promises. It is designed to give you a good boost of energy whilst suppressing your appetite and increasing the rate at which you burn fat (thermogenesis, see below), which it does well. A lot of this is courtesy of a large dose of caffeine, taken from various sources. In fact, you get about five shots of espresso’s worth of caffeine in each serving.

This makes it potentially unsafe for some, and will likely cause some minor side effects in most, but there is no arguing with its efficacy.

Caffeine isn’t just a stimulant, of course. It’s also one of the best thermogenic compounds going. There are a host of other thermogenic ingredients included in the formula (again, see below), alongside a good vitamin and mineral complex aimed at keeping you healthy, strong, and efficient as you lose weight, as well as one of the best appetite suppressing fibres going.

Roar Ambition are a great company to buy from. They keep the quality of their supplements high whilst keeping costs fairly reasonable by cutting out third party vendors. You can only ever buy direct from them, so you’ll never see them in shops or other websites. This means that you get premium products without the premium price tags. 

How Instant Knockout Works

Instant Knockout is a thermogenic far burner. This means that it works by increasing rates of thermogenesis in your body.

The word thermogenesis comes from a combination of the Greek words thermos, meaning heat, and genesis, meaning creation. Thermogenesis is the creation of heat from stored energy. As your body stores energy as fat, this means using up more body fat than usual.

InstantKnockout bottle

In fact, a good thermogenic fat burner like Instant Knockout can generally increase your calorie expenditure by 50-100 calories per day. This may not sound like much. You need to eat to a 500 calorie daily deficit, which will mean around 1700-2000 for most people. A typical chocolate bar contains around 250-300 calories. This makes those 50-100 calories seem a little paltry.

However, add these to your existing deficit and you’ll see far more efficiency in your weight loss.

This isn’t the only role of a good thermogenic fat burner, either.

Quite often, as we restrict calories, our metabolisms slow down. Your body doesn’t want to use up its energy reserves. It wants to hold onto them, saving them for when they might be needed.

Therefore, it will use less and less energy in the presence of an energy deficit in an attempt to maintain fat levels. You need to undo this if you want to lose weight efficiently. Those 50-100 calories represent this.

The thermogenesis inspired by fat burners will do this. Instant Knockout will keep your metabolism working on full, allowing you to really make the most of your calorie deficit and active lifestyle.

In addition, we have already talked about energy. Not energy as stored calories, but rather your perceived energy levels.

Your ability to remain switched on where a calorie deficit may make you sluggish. Again, increased thermogenesis means an increase in energy used. This may undo a small amount of that lethargy in itself. There is also generally a fair amount of stimulant content in any given far burner (though this isn’t always the case – there are some great, low-stimulant or stimulant free options on the market).

As we have seen, this is very much true of Instant Knockout.

You get lots of caffeine, which should give you an almighty energy kick. Beware the crash – what comes up must come down, and all that. But if you need something to get you going at a key moment, this will do the job.

Fat burners are often not simply about ‘burning fat’ or eliciting thermogenesis. Improved rates of thermogenesis are all well and good. However, they can’t make up for excessive eating. You need a calorie deficit in place. This is the only way you will lose weight.

Everything else is simply there to make the deficit more effective. However, as anybody who has ever followed a restricted eating plan will tell you, it is hard to under-eat. Hunger pangs and cravings are always there, threatening to get the better of you.

Instant Knockout follows a good trend in the fat burning world by also working as an effective appetite suppressant. Its formula contains glucomannan, one of the best soluble dietary fibres going. It will swell up to fifty times its starting size in the stomach and throughout the digestive tract. This will make you feel fuller for longer.

It will also undo some of the nastier effects of restrictive eating. Most low-calorie diets are low on fibre, which is vital to digestive, gut, and cholesterol health.

There are also some neurological abilities that certain compounds possess that can help to curb your appetite. They effectively inhibit your brain from signalling to you that you need to eat. Caffeine and cayenne pepper, two key ingredients in Instant Knockout’s formula, both do this admirably.

So you have multiple attack vectors, here. Instant Knockout doesn’t simply help to ‘burn more fat’. It can do this, or at least it can boost thermogenesis, causing your body to use up fat as energy reserves. However, it also gives you a good energy kick, allowing you to live the life you want without fear of diet-induced sluggishness.

It suppresses your appetite to a fair degree through multiple mechanisms, both physical and mental. In short, it makes everything about managing a calorie deficit and active lifestyle for weight loss far more manageable and effective.

Instant Knockout Ingredients

Any supplement will only be as good as its ingredients list, of course – what else is a supplement but a (hopefully) clever mixture of relevant components? And this is where Instant Knockout shines – it has a superb, if slightly overbearing, ingredients list.

You get a good vitamin and mineral complex with Instant Knockout. These include B6 and B12, chromium picolinate, and zinc. These are all linked with various mechanisms for weight loss, as well as playing key roles in hormone stabilisation and optimal output (especially zinc, and especially for men).

These set a good baseline for the real work to begin. It begins with green tea extract, one of my favourite supplements. It’s a fantastic thermogenic ingredient in its own right, with a wealth of clinical data backing up its efficacy. It will also aid concentration and focus, which can both be impaired by on a low-calorie diet.

Most of its benefits revolve around the catechins it contains, a powerful form of antioxidant. They are absorbed by your body, where they lead to an increase in the hormone norepinephrine. Norepinephrine is one of the key hormones related to fat burning. Too little of it can lead to otherwise unexplained weight gain. Optimal levels will mean optimal fat burning.

Green tea also contains a small amount of the amino acid l-theanine, one of my favourite nootropic (brain health) ingredients. It has been linked to improved attention and focus, as well as a drop in anxiety and stress.

The thermogenesis continues with green coffee bean (beans that haven’t been roasted). In being left in their raw form, green coffee beans retain their chlorogenic acid, which is what we’re looking for here.

Green coffee bean’s chlorogenic acid helps to diminish glucose storage in the liver. This glucose is your body’s preferred energy source. While there is glucose in your system, it won’t use fat for energy. However, clearing this glucose out will force your body to burn fat for energy. 

This has been born out in clinical studies. In one, three-month study, obese participants took instant coffee enriched with chlorogenic acid every day. They lost an average of 12 lbs, or 5.4 kg, compared to control groups.

Then we come to the big guns, beginning with cayenne pepper, one of the best-known, most well-studied thermogenic compounds going. Of course, you can eat it in any hot dish, giving you a lovely, fiery kick. However, for optimal results, supplementation is always a good idea. This way you get plenty of capsaicin, its active ingredients.

Capsaicin is what gives chillies their heat. It can also lead to increased temperatures in your body itself, eliciting thermogenesis and turning stored fat into heat. Or, rather, raising your body’s temperature so that the body has to use more energy to cool itself and thereafter regulate its temperature.

This, in a nutshell, is what we’re looking for from a thermogenic ingredient, and capsaicin does it admirably.

Clinical data back this up, showing that capsaicin consumption can help to boost your body’s overall daily energy expenditure – energy measured as calories, of course. Capsaicin goes further, however. It isn’t here simply for its thermogenic properties. It has also been shown to suppress your appetite and increase satiation, meaning that you feel fuller for longer.

This satiation is backed up by glucomannan, one of the best, healthiest appetite suppressing fibres going. It’s sourced from the konjac root, so you may see it listed elsewhere simply as ‘konjac root’. And you will see it plenty of places – any thermogenic supplement not using it is missing out, wasting a great opportunity.

It swells in your stomach, as all fibre does.

However, glucomannan is particularly absorbent. It can swell to around fifty times its starting size. This means you have to drink plenty of water, both to make it work fully and in order to avoid dehydration. But if you do, you’ll be onto something good.

This swelling serves a couple of roles. Firstly, it increases satiation as it sits in your stomach, filling you up. Secondly, it improves your digestive health, bulking out your stools, and your stomach flora, nourishing it with good quality fibre. 

Glucomannan has been shown to lead to an average weight loss of .5 lbs over an 8-week period with no other variables (exercise, diet, and so on) changing.

Then there is caffeine, the main event in Instant Knockout’s formula. It isn’t the best ingredient on the list. Realistically, if it just contained glucomannan, capsaicin, and perhaps green tea, it would work well. However, caffeine elevates the whole lot, especially when dosed as it is here.

Caffeine serves two key roles in Instant Knockout, or perhaps even three – it is also a mild appetite suppressant. However, we’re mainly looking at it for its energy giving and metabolism boosting properties.

It is a thermogenic ingredient, nearly as potent as capsaicin. It’s been proven to increase energy expenditure in the same way, even at rest, all things being equal. Take it in large quantities and your body will likely end up using far more calories than it otherwise would.

Then there is the energy side of things. Caffeine works in a couple of ways.

Firstly, it prompts the fight or flight response, boosting adrenaline and raising your heart rate. Secondly, it interacts with a neurochemical called adenosine, which is a waste product of the energy system. Your body uses adenosine triphosphate for energy, powering most of its major processes.

The adenosine component is then released back into your system. From here, it binds to your brain’s nerve cells. It triggers a rest response, causing your brain to wind down and, eventually, fall asleep.

Caffeine has a similar structure to adenosine. It binds to the brain’s nerve cells instead, leaving the adenosine floating free. The brain therefore doesn’t slow down. Whilst there is caffeine present, it stays energetic. As do your body’s cells, which leads to the boost in energy and metabolic function.

This doesn’t last indefinitely. The adenosine is still there. When the caffeine is used up, it will flood the brain, leading to that energy crash we all know. However, for the duration, you will have more energy and a heightened metabolism, allowing you to get on with what you need to whilst burning through extra fat.

Using Instant Knockout

Instant Knockout very much does what it says on the tin. I’ve used it before. As an ex-martial artist, fitness expert, and supplement lover, it has always very much been on my radar. I tried it again for this Instant Knockout review and nothing much had changed – it’s still incredibly potent!

Firstly, I don’t really train in martial arts anymore. My current regime revolves around weightlifting, HIIT, yoga, and walking.

I used Instant Knockout as a pre-workout on my weightlifting and HIIT days, scheduling the gym for half an hour after my first dose of the day. The rush was intense – I was buzzing all the way to the gym and home again. It enabled me to push myself as hard as I wanted even whilst cutting a few hundred calories from my daily diet.

It was less helpful with yoga. Peace of mind doesn’t come too easily when you’re on this much caffeine. However, take it early in the day and practice yoga in the evening and you’ll be fine. I was.

And that calorie deficit was easy to come by. I hate under-eating. I take great pleasure from cooking and eating plenty. However, with a decent dose of glucomannan, as much as I might have missed the large meals, I didn’t crave more food. I was fine on what I was eating, with no hunger pangs until just twenty minutes or so before my next meal each time.

My digestive health was also sound, which isn’t always the case on a restricted eating plan, and which was very, very welcome.

All this combined with a good thermogenic kick to give me a decent amount of weight loss. I managed to shift 3 kilograms of bodyweight in one month, which is around seven pounds or so. Given I’m pretty lean to begin with, that’s good going. Those with more to lose will likely experience far more pronounced results, especially in the first few weeks.

It’s not cheap, but then few fat burners are. It is, however, an incredibly good use of your money. It will do exactly what you need it to do, giving you some genuinely fantastic benefits.


I would happily recommend Instant Knockout to a few types of people. If you’re active, healthy, have no issue with caffeine and haven’t suffered with caffeine sensitivity, and if you’re looking to lose a bit of weight whilst keeping up an active lifestyle, it is perfect for you.

Do note that you should reduce your caffeine consumption elsewhere. I’m a prolific coffee drinker and I toned this down when using Instant Knockout. If you don’t, you’re getting into unsafe territory.

If you struggle with blood pressure or heart concerns, if you’re sensitive to caffeine, or if you have any digestive concerns (which caffeine may irritate), then I would steer clear. In fact, if you have any underlying health concerns at all, I would consult your doctor before taking Instant Knockout.

There are some great low-stimulant or stimulant-free thermogenic options out there. They may be more appropriate for your needs.

Anyone else, anyone who can safely, comfortable take it, go for it. It’s a very good supplement, well-blended, potently dosed, with a great deal of scientific underpinning. There are few thermogenic supplements out there that can compete Instant Knockout.