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Instant Knockout Fat Burner Review
Read This Before You Buy

Isaac Robertson
Published by Isaac Robertson
Fact checked by Donald Christman, BHSc FACT CHECKED
Last updated: July 4, 2021

As a fitness instructor, I work with a lot of high-performance athletes on a daily basis. It’s usually a mix of bodybuilders and just average people who need some help with their health, and fitness goals.

Recently, I’ve also started working with MMA fighters, and one of my clients recently introduced me to Instant Knockout. While I’m a fan of fat burners, I’m also very cautious of all the dodgy weight loss supplements out there.

But because of the results I have witnessed, I decided to do some more research and look into the ingredients with a dietitian to put together this detailed Instant Knockout review.

What Makes Instant Knockout Unique?

instant knockout fat burning product

If you’ve followed any health and fitness page on Facebook or you just happen to read posts about muscle building, then you’ll quickly notice a load of suspicious fat burners on your news feed.

The fat burning industry is a huge business, and unfortunately, there are too many black sheep promising to help you lose weight quick.

However, my suspicions about Instant Knockout were instantly reduced when I saw that there was a lot of backing from MMA fighters and coaches like Diego Sanchez and Greg Jackson.


The company behind Instant Knockout is Roar Ambition, and their goal is to make the most effective fat burner using natural ingredients that are scientifically proven to help athletes get rid of fat, build more muscle, and support weight loss.

But it would have to work for professional athletes at the top of their game, as well as average people who just want to bulk up a bit or lose weight.

We’ll get to the details of Instant Knockout's nutritional label below, but I can say here that a lot of thought has gone into creating this product.


What Are The Benefits Of Instant Knockout?

Instant Knockout Benefits

I wanted to focus this Instant Knockout review on its nutritional label. The brand claims to have an all-natural list of ingredients that could potentially help you with weight loss without the unnecessary side effects.

I'll discuss those ingredients and what they do in detail, but let's talk about the product claims first.

1. Fat Loss

This might be an obvious benefit of fat burners, but it really can be hit and miss with these types of supplements. However, Instant Knockout contains ingredients that not only help with fat burning and losing weight but also in controlling the process that stores body fat in the first place.

2. Increased Energy Levels

When your body burns more fat, then more energy is released to fuel different parts of your body. But what I found in many different Instant Knockout reviews is that people also noticed a good increase in mental energy levels and focus.

This means that it may help with workouts by staying motivated, but also at work and school when you need your brain to work on complex problems.

  • Strong dosage of caffeine from green tea extract for mental performance and thermogenic effects for weight loss
  • 10 mg of zinc boosts testosterone production for more muscle growth
  • Nice dose of glucomannan to help as an appetite suppressant
  • Includes cayenne pepper which helps as a fat burner to shed off more calories
  • You’ll need a reminder to take 4 pills per day

OK, with all these pros and cons, we can say that Instant Knockout promises good stuff.  What about the negatives?

Are There Any Side Effects?

Side Effects - Instant Knockout Review

Fat burners and weight loss pills have had quite a bad reputation.

Sure, a lot of them may be effective at weight loss, but many can also cause upset stomach, which isn’t ideal to stay motivated on a weight loss program.

The good news is that because it is made of the most natural ingredients my dietitian has encountered, the side effects really are limited.

The one area where you may want to be careful with Instant Knockout is the 300 mg of caffeine on a full dosage which is the same amount you get in 2 large coffees.


If you’re planning out your daily intake of Instant Knockout, then you may want to skip a few trips to Starbucks.

For those dealing with side effects, check out the best stim-free fat burners or top natural weight loss supplements.

Weight Loss Ingredients And Their Effects

Now that you have a good picture of the product's benefits and side effects, let’s take a closer look at how effective the ingredients in Instant Knockout are at stimulating energy levels, fat oxidation, weight loss, and appetite supression.

1 - Caffeine Anhydrous

caffeine anhydrous2

According to my dietitian, caffeine anhydrous is one of the most closely studied thermogenic ingredients.

This is probably why Roar Ambition decided to make it a major feature on Instant Knockout's ingredients list.

While some athletes have trouble with caffeine anhydrous as a stimulant, you should note that there is very good scientific evidence [1] backing up the claim that it encourages your metabolic rate to burn fat and lose weight.

2 - Green Tea Extract

green tea extract2

I used to force myself to drink some green tea every day. It’s just not a taste I enjoy, but I totally understand the antioxidant benefits it provides.

But, when I found that you can get a fat burner that contain green tea extract, I jumped on the opportunity.

Instant Knockout only contains a small amount of caffeine from its green tea extract, but I found a very interesting study that highlighted a direct link to body fat oxidation [2].

3 - Cayenne Pepper Seeds

Cayenne Pepper Seeds2

Cayenne pepper is a well known thermogenic, but what I found more interesting was the company’s claim that it “boosts insulin sensitivity helping improve the way you store carbs.”

Not surprisingly, at this stage of my research, I was able to find supporting studies of this [3].

4 - Zinc


This metal influences a lot of processes in your body from immune health to stabilizing effects on your metabolism.

Moreover, moderate intake of zinc helps to increase testosterone levels [4].

I saw quite a few review comments where athletes actually had some hormone level tests done before and after taking Instant Knockout.

In all cases, there was a positive impact on T-count.

5 - Green Coffee Bean

green coffee bean with chlorogenic acid

Apart from containing a significant amount of green tea extract, Instant Knockout also has green coffee bean extract.

The benefit of this ingredient comes from the fact that a lot of nutrition is lost during the coffee roasting process. I found one very interesting study that showed that green coffee bean extract helps in burning fat and improving heart health [5].

It also contains a good amount of chlorogenic acid which acts as an antioxidant.

6 - Glucomannan


This product contains glucomannan extract sourced from the konjac root, which was new to me.

Unlike most of the other ingredients, this is not included based on an ability to burn fat in an effective way.

Instead, glucomannan helps to suppress appetite by delivering a good amount of dietary fiber to make you feel fuller for longer.

7 - Chromium


This is not a mineral I was overly familiar with, and I hadn’t seen it before in supplements except in this one.

Instant Knockout contains GTF chromium as picolinate, which acts as a protein that boosts insulin action.

My dietitian pointed out that increasing number of clinical reviews and meta analyses are being conducted to fully identify its effects on body weight [6].

It is also linked to controlling appetite, and many of the reviews I read highlighted a lack of hunger as a great positive of Instant Knockout.

8 - Piperine

This is another one of the very versatile Instant Knockout ingredients that has a lot of nutritional value.

It’s included in many products, and my dietitian goes as far as saying it is required to make absorption rates higher for both macro and micronutrients.

Piperine (from black pepper) can enhance the absorption or bioavailability of certain compounds, such as curcumin from turmeric.

9 - Vitamin B6

Vitamin B6

We all know how important vitamins are, and your daily nutrition intake has to cover a very wide range of them.

Vitamin B6 has been added due to a claimed link to the way cells repair and reproduce, which is an important factor in muscle building [7].

Just check if your multivitamin also contains B6, as you may want to avoid taking too much.

10 - Vitamin B12

Instant Knockout contains more vitamin B12 than you need every day.

Most people will link this vitamin to influencing your red blood cell count, but vitamin B12 also helps with fat oxidation and metabolism [8].

When Should You Take Instant Knockout?

box of instant knockout

Every time I recommend weight loss supplements like fat burners, one of the first questions is always “what time of day should you take them?”

Instant Knockout is designed to provide maximum nutrition value throughout the day by splitting your intake into 4 pills.

This spreads out the fat burning effects and delivers a more constant stream of extra energy.

One thing I noted in a few reviews about Instant Knockout and other was that athletes suggested setting a reminder on your phone or get into the habit of taking a capsule every time you eat a meal.


Some also mentioned that because of the caffeine from green tea extract, you might have to avoid taking it too late in the day.

Is it Suitable For Women?

For women, weight loss is often a higher priority than muscle gain. The good news is that Instant Knockout is not specifically a muscle building product. This means that women can take full advantage of effective fat burning properties for increased energy and weight loss.

One thing I would caution, though, is that the amount of caffeine in Instant Knockout is quite high when the full volume is taken each day. You may want to start with just 2 or 3 capsules a day.

Up to 400 milligrams (mg) of caffeine a day appears to be safe for most healthy adults. That's roughly the amount of caffeine in four cups of brewed coffee, 10 cans of cola or two "energy shot" drinks.

-Mayo Clinic

Where Is The Best Place To Buy Instant Knockout?

I always recommend buying directly from the Instant Knockout's official website. It is the only place that it’s officially available, and with so many counterfeit products on the market, there are too many health risks you could expose yourself to.

This is also the only way you can take advantage of the money-back guarantee, as well as some very good bulk-order prices. Since I ordered my first supply of Instant Knockout, I now always go for the “Ultimate Shredding Stack” from the official website to save money.

If the Instant Knockout doesn't work for you or simply want to try a month supply,  you can always take advantage of their 90-day money-back guarantee.

 Other popular fat burners:


instant knockout faq banner

Do You Take Instant Knockout With Food?

Yes, you should aim to take Instant Knockout with food. This is generally a good approach for all supplements like a fat burner to reduce the chance of an upset stomach and make the product more effective.

Is Instant Knockout a Thermogenic?

Yes, Instant Knockout is a thermogenic, which means it increases your core body temperature slightly by boosting your metabolic rate which results to possible weight loss.

It contains green tea extract, cayenne pepper, and green coffee bean extract which are known for their thermogenic effects that may help you lose weight.

How Do You Take Instant Knockout?

Take 1 pill of Instant Knockout 4 times per day with meals and snacks. Because it’s in pill form, it’s easy to adjust your intake up or down as required to achieve your weight loss goals.

Does Instant Knockout Fat Burner Work?

Yes, Instant Knockout fat burner does work, and you can see this in all the positive product reviews online. Of all the fat burning supplements available right now, this is the one that has the most scientific research backing up its powerful effects.

Can I Stack Instant Knockout With Other Supplements?

Yes, you can stack Instant Knockout as fat burner with other supplements. However, because the recommended serving of Instant Knockout has about 300 mg of caffeine, you have to be mindful of the caffeine content of the products you plan to stack it with.

How Long Does It Take For Instant Knockout To Work?

It varies as some users lose weight in just a few weeks while others take a month or longer. It is recommended to give the product 30 to 60 days to assess whether or not it works for you.

Is Instant Knockout FDA-Approved?

Like any other fat burns, Instant Knockout is not FDA-approved. However, it is regulated by FDA which works against adulterated or misbranded dietary supplements.

Is Instant Knockout Worth The Investment?

After 3 months of trying the product out for this Instant Knockout review, analyzing the content with a nutrition expert, and reading through hundreds of reviews, I have to say that this fat burner is my personal favorite, and the one I recommend to my clients.

The weight loss effect is noticeable, and I have tried it during 2 cutting phases, where each time I reached my goals a few days early.

You can purchase 3 bottles of the product and get a free bottle plus free shipping from their official website.

Once you have tried it out for a few weeks, make sure you get in contact with us on social media or use the contact page on this site.

Instant Knockout Box

Instant Knockout

Our #1 Recommendation

  • Strong dosage of caffeine for mental performance
  • Boosts testosterone production
  • Nice dose of glucomannan
  • Includes cayenne pepper which helps with fat burning and weight loss
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9 thoughts on “Instant Knockout Fat Burner Review
Read This Before You Buy

  1. Thanks to this instant knockout review, I’m now leaner and stronger! Gotta say that this fat burner is legit!

  2. I have shed over 30 pounds using this product and with the right gym sessions and regime, I was able to gain so me muscles too. This one is legit. I highly recommend it. I experienced a little bit of a reaction during the first few days, I could not sleep! But eventually my body adjusted to it and I felt great. It gave me more energy and I felt the burn everytime I do my routine. My friend who’s into fitness even commended me because I work too hard and give it my all when I am in the gym! All because of this product. I love that it does it what it’s supposed to do and more

  3. Hey Isaac. It has been a while since I last visited your post. By the way, thanks for your awesome breakdown of this wonderful product. I have been using it for a little while now since I saw it in your website. What I have noticed while using this product is that with the high caffeine dosage, I can’t drink a cup of coffee in the morning and take this at the same time without stomach issues. I received an advice from my friend a couple of days ago saying he can help me out with my stomach issues. I look forward to reading more from you. Thanks in advance!

  4. Just wanted to say that thank you as always for your in-depth analysis of this amazing product. Since postage, I have been using this product for about 2 months now. Within that span of time, I went from 250 to 210 pounds! It was a great milestone for me because usually it takes me longer to lose so much. To give a background of what I have been doing, I rarely worked out or went to the gym. I just ate healthier, all the fruits and vegetables and less of those junk. I walked 4 miles every other day, and just was sensible about everything I did or ate. I believe it works great for losing stubborn belly fat as my friends have noticed a great loss in my abdomen area and in other smaller noticeable areas of my body. Which is kind of great since it has been a long time that I wanted to get rid of those. Furthermore, most notably though and focused in the stomach. I used to have a very big belly and it protruded out significantly. I don’t really drink heavily though that’s why it makes me wonder why I had it. However, I do notice while on it during my weight loss journey that it did sometimes cause minor weight gain by at most 2 pounds. But really, if you’re at least casually active, you should be able to work that off easily enough. I would recommend if you are a bigger person who may not be as big as I am or was would notice any significant reduction. It will probably take more time if you are already a leaner or fit individual according to my friends who are way, way lighter than me. At my current weight of 210 pounds, it has been harder and extremely slow to lose any more of my weight but I am trying hard to continue to lose the weight and slim down. After all, it has worked for me and I have proven it myself. So let’s keep ourselves posted guys. Once again, thanks Isaac!

  5. I’m a 26 year old woman and I’ve been using this magical product for about 6 months now. I found this product online but was a little sketchy until Isaac wrote down his thoughts on it. This pushed me to purchase it doubt-free. When I started using it, I was at around 63kg. Now as of writing this, I am bouncing around 53kg. I couldn’t be more happier than this that I can maintain almost near my ideal weight. To top it off, I lost that much with minimal exercise and limited diet. I guess any pills will work best especially coupled with a healthy diet. I live on a tiny island nation with little to no access to healthy food so for me, maintaining to eat a healthy diet really needed a significant input of an effort which has been worthwhile so far. I started seeing definite changes to my form in the second month. Initially I did suffer from sleeping problems due to caffeine sensitivity. Normally, I don’t drink coffee even when I have to keep myself awake during midnight. However, 6 months later, it’s not so much of an issue now. My biggest sticking point is 4 times a day can be hard to remember sometimes. This is definitely not a joke. As far as I can remember, I probably have wasted my first month because I’d forget to take it later in the day… But overall, I’m happy with the results. I have more energy during the day, and losing those unwanted curves has motivated me to keep on doing strenuous physical activities.

  6. Isaac has been my go-to when it comes to this topic. I started taking this pills not so long ago. I was going to the gym maybe 6 times a week before, but I was doing that before I started taking these pills. Definitely, I saw an impact when I ate sweet stuff. I had no idea why. To begin with, I did not even like the taste of it. Because of that, I totally stopped eating it. Also, for some reason, I always felt full. I noticed that my body fat percentage went from 23% to 19% over a 2 month period. Occasionally, I stop using this product because of limited stocks. Since then, I stopped taking them and noticed that my appetite has gone up a bit. But I do feel more controlled when it comes to eating sweet stuff. Would definitely take these again as a quick fix for a holiday body as they give energy during exercise and stop my uncontrollable cravings! Thanks Isaac.

  7. I ordered this product a little hesitantly, after trying various products previously which all promised fantastic results immediately but rarely work, and instead saw myself gaining weight which I really hated. I found the price was not overly excessive, especially for a month’s supply. I was definitely sold on your thoughts Sir Robertson as you have always been honest with what you say. Initially not expecting much, I started on day one with my morning pill just before breakfast. Within ten minutes I felt full without taking a bite. This was rather strange. Naturally, I was a little surprised as I did not expect the appetite suppression to take effect so quickly. I continued throughout the course, sticking strictly to my diet and consuming the four pills daily. I have since started the same plan again to really pin down the difference on and off this wonderful product. All in all I would highly recommend this product to anyone struggling to stick to a plan. As much as discipline is important, a well-engineered product makes a world of a difference. I am glad I listened to this author.

  8. I decided to try this product after trying several other products that failed my expectations. And after tons of research, I took the leap after I came upon this website. I am a new reader of Isaac but I have never read anything like this before. So I bought it immediately. Boy am I glad I did! I will admit the first couple of days I was on such a high, it was hard to sleep. I eventually got used to it and continued with my weight training. I eat pretty well so I really didn’t change my diet. I had increased energy, stopped eating out of boredom and felt so much stronger at the gym. I was on fire! Even after the first 2 weeks on this product, I saw results. I was in awe! If you are contemplating on trying it out I highly recommend it. Thank you Isaac for bringing out this product. You have really assisted me in reaching my goals.

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