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Instant Knockout

Instant Knockout

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26 Customer Reviews


Instant Knockout is a nutritional supplement that’s claimed to use all-natural ingredients to help increase your metabolism and reduce hunger cravings.

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Instant Knockout Review - Does It Work?

By Anthony Dugarte, M.D., C.S.C.S

Updated on: Mar 16, 2020

Instant Knockout is a nutritional supplement that allegedly helps address your body fat and boost your metabolism.

According to their website, Instant Knockout was originally developed for MMA fighters and boxers in need of cutting fat and retaining muscle as they prepare for weigh-ins.

Instant Knockout claims that their blend of natural ingredients accomplish help you burn fat through 3 mechanisms:

  • increasing your metabolism
  • suppressing your appetite
  • increasing your energy

They state that you can experience these benefits simply by taking 4 gelcaps daily - one first thing in the morning, one before lunch, one in the afternoon, and one before dinner.

Keep in mind, Instant Knockout suggests using their supplement in conjunction with a healthy diet and regular exercise - 2 factors that may offer weight loss on their own.

In this article, we’ll touch on the scientific support available for their blend of ingredients to help you determine if you need to add Instant Knockout to your daily routine.

Instant Knockout Ingredients: Do They Work?

In this section, we’ll touch on each of the ingredients in Instant Knockout to help you determine if the science backs up these lofty claims.

You’ll get each of the following doses in every 4 gelcaps:

Vitamin B6 (as pyridoxine HCI) 5 mg and Vitamin B12 (as cyanocobalamin) 10 mcg

You can obtain B Vitamins from meat, seeds, and nuts. They are thought to support brain and nerve health, red blood cell function, energy metabolism, and weight loss.

Vitamin B6 may offer energy-boosting effects through its role in blood sugar regulation. In a Japanese study, those with type 2 diabetes and a high dietary intake of B6 were less likely to have diabetic eye disease.

Vitamin B12 deficiency has been linked with fatigue. While supplementation may boost energy, the effects are likely less noticeable in those with adequate intake.

Zinc (as zinc oxide) 10 mg

Zinc is an essential mineral found in many of the foods that also offer B vitamins. Deficiency is common, especially in those older than 65.

Zinc levels were shown to be significantly lower in obese kids when compared to those at a healthy weight. Low levels were also found to be associated with obesity, elevated BMI, and larger waist circumference in women.

A randomized trial found that 30mg of zinc daily over 4-weeks decreased both BMI and body weight in obese subjects. These effects were also seen in obese children that were randomized to treatment with 20mg per day over 2-months.

Instant Knockout seems to offer one-half to one-third of the amount found beneficial in previous studies.

GTF Chromium (as picolinate) 100 mcg

Chromium is another mineral which is found in beef, fruits, broccoli, and whole-wheat products.

A review of 15 randomized trials found no benefit for energy metabolism at doses ranging from 10-1000mcg.

Regarding weight loss, a review of 20 randomized studies found chromium supplementation offered only mild benefit in overweight and obese individuals.

While chromium seems to offer only mild benefits, positive results are less likely as Instant Knockout offers a dose on the lower end of the spectrum.

Green Tea Extract (leaf) 500mg

Green tea is commonly added to fat-burning products as it may offer a variety of benefits related to boosting energy and sparking weight loss.

The purported benefits of green tea are actually related to its caffeine and catechin content.

When combined with 200mg caffeine, green tea at 90, 200, 300 and 400 mg doses up to 3x daily all seemed to boost energy expenditure to the same degree.

When combined with exercise, 500mg of green tea daily improved body weight, BMI, waist to hip ratio, and body fat percentage better than exercise alone.

Instant Knockout seems to offer plenty of this extract as it was demonstrated to be effective at even much smaller doses.

Green Coffee Extract (bean) 100 mg

Green coffee bean extract (GCBE) offers another source of caffeine and may help reduce appetite.

A review of 3 randomized trials with GCBE doses ranging 180-200mg over 1-4 months found that significant weight loss was achieved when compared to placebo.

Obese women treated with 500mg of GCBE and daily exercise for 2-months also found benefit; they significantly reduced their metabolic syndrome severity scores.

Cayenne Powder (fruit) 100mg

Not just used to spice up your food, cayenne peppers have been included in natural medicine for centuries.

Their active ingredient, capsaicin, is thought to offer a number of health benefits related to increasing your metabolism.

While this effect may be possible, cayenne seems to offer only mild benefits in this regard.

In a randomized trial, those that consumed 1g of cayenne burned an extra 10 calories over the span of 4.5 hours. A review confirmed these findings; capsaicin at high doses seems to boost energy expenditure and fat burning, though only to a minor degree.

Glucomannan (konjac root) 1800mg

This natural, water-soluble dietary fiber is extracted from the roots of the elephant yam or konjac.

Like all fiber, it can absorb water and turn into a gel that takes up space in your stomach. Such absorption leads to a sensation of fullness that may reduce your calorie intake.

This effect did not lead to positive results in a randomized trial. Treatment with 1.3g of glucomannan over 2-months did not improve weight, body composition, or hunger in overweight and obese subjects.

In overweight and obese adults, treatment with 3g of glucomannan for 2-months did not result in significant weight loss or reduction in body fat when compared to placebo.

Even at doses nearly double of what is offered in Instant Knockout don’t seem to offer metabolic benefits.

Caffeine Anhydrous 300mg

Caffeine is a stimulant that has been well studied for its proposed metabolism-boosting effects.

Caffeine given to healthy subjects at 3 mg/kg before physical activity resulted in more fat oxidation when compared to those that didn’t receive caffeine. These effects were less pronounced in obese women, however.

In another study, men that consumed 300mg of caffeine 30 minutes before a meal consumed less food. However, this effect was not seen in women.

While caffeine seems to offer metabolic benefits, the potential for results seems to vary depending on the group of individuals being studied.

Black Pepper Extract (standardized to 95% PE) 10mg

This spice may offer metabolism-boosting benefits in addition to its role in the cuisine.

In overweight individuals randomized to treatment with 6mg of black pepper daily, supplementation led to reduced BMI and body fat.

Are There Any Side Effects?

Most of the ingredients included in Instant Knockout have been well tolerated even when studied at much higher doses.

It does contain 3 different sources of caffeine, however. According to the FDA, the rapid consumption of 1,200mg of caffeine can cause seizures.

In particular, caffeine anhydrous is a highly concentrated form of the stimulant; you may react differently than you have with natural forms of caffeine. This can be especially dangerous if you have a history of heart conditions.

Excess caffeine can lead to restlessness, nausea, agitation, rapid heart rate, and elevated blood pressure.

While 400mg daily is considered to be safe, consuming Instant Knockout in addition to your typical coffee, soda, or tea habits can put you at an unsafe range.

For these reasons, it is imperative to ask a physician about using this product and never consume Instant Knockout in ways other than what is recommended.

How Much Does Instant Knockout Cost and Where Can I Get It?

You can pick up Instant Knockout online from a few vendors, though pricing differs substantially.

Check out the chart below of a cost comparison (1-month supply = 120 gelcaps):






Instant Knockout

$59.00 (30 day)



See Below


$64.77 (30 day)

Free with Prime



Roar Ambition

$59.00 (30 day)





$88.17 (30 day)




You have a few more options if you purchase through the Instant Knockout Site.

They offer a 2-months supply with free delivery for $11800. The “Ultimate Shredding Stack” comes with a 3-month supply + 1 free bottle for $185.00.

The limited-time offer currently running gets you 3 bottles of instant knockout and 3 free bottles of their women’s fat burner, also priced at $185.00.

Lastly, Instant Knockout backs each purchase with a 90-day guarantee.

Available Alternatives

With so many individuals interested in burning fat, many vendors offer supplements that claim to accomplish this task.

Of the products that offer natural ingredients, you’ll often find some overlap though formulations vary vendor to vendor.

Smart Burn from bpi Sports offers both caffeine anhydrous and green tea extract in their powdered blend. A 15-day supply will run you $26.99.

You’ll recognize some of the ingredients offered in Transform from Evlution Nutrition: a 30-day supply of capsules includes B vitamins, green tea extract, caffeine, and black pepper extract for $22.49.

Though this blend is not identical to Instant Knockout, it may be a more cost-effective means of accomplishing your goal at less than half the price.

As the ingredients offered in Instant Knockout are commonly added to fat burning supplements, they can also be obtained individually. This method may be less convenient and even more expensive.

The Bottom Line

Instant Knockout does offer a blend of natural ingredients that seem to have some scientific support regarding their metabolic effects.

However, some of these ingredients lack strong support, while others were found effective at doses much higher than those provided in this supplement.

Also, Instant Knockout contains 3 different sources of caffeine. While this stimulant may offer metabolism-boosting benefits, it can be unsafe when taken in excess.

Refrain from use other than as directed, do not ingest at bedtime, and be mindful of other sources of caffeine you consume like coffee or soda.

At HighYa, 25 users rated this product with an average of 1.3 out of 5-stars. Unhappy customers cite a lack of results and a failure to honor the 90-day guarantee as reasons for their poor experience.

When you combine this information with the hefty price tag, you may want to seek fat-burning help elsewhere.

As Instant Knockout suggests use with 2 proven methods of weight loss, diet and exercise, you may want to start with these lifestyle changes before adding a supplement like this.

Nonetheless, if you’re still interested in using this or any similar products, always speak with your doctor first.

Customer Reviews

1.3 Stars out of 26 Reviews
5 Star:0% 4 Star:7% 3 Star:3% 2 Star:0% 1 Star:88%
15% Recommend This Company
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Posted on Nov 23, 2021

Instant Knockout, Roar Ambition

By Ginny R., London, United Kingdom, Verified Reviewer

Avoid this company and product! After the first tablet, I developed a headache that persisted over four days. It left me feeling very ill, tired, gave me a persistent headache, and despite my symptoms, Roar Ambition refused to refund me. Exceptionally poor customer experience. Useless and dangerous product.

Length of Use: Less than 3 months

Bottom Line: No, I would not recommend this to a friend

Pros and Cons

No “pros” were specified in this review

Misleading information

False advertising

Poor customer service

Helpful Review? 1 Person Has Voted

Posted on Oct 15, 2019

Fraud, scam, never buy it

By Santosh A., India, Verified Reviewer

I ordered this product from their website, it was for free delivery for buying 3 products together, and it cost me 6000 rupees more as custom charge, on delivery, and when I tried to contact their support, they stopped replying me,

Very bad experience, it even took one month for delivery.

And also this supplement doesn't found so effective, it looks fake, it doesn't give that much kick, or strength in work out just like we found strength in normal pre-workout. Even musblaze pre-workout is best than this supplement.

Never ever buy this supplement, it's a waste of money.

In case if support doesn't respond to your query contact Roar Ambition company's CEO on LinkedIn.

Bottom Line: Yes, I would recommend this to a friend

Helpful Review? 2 People Have Voted

Posted on Feb 28, 2019

Misleading/false advertisement

By Sophia P., Detroit, MI, Verified Reviewer

This product has not done anything it says it does. I have taken it for three weeks with no increase in energy and absolutely no weight loss. I am an active person who works out five days a week with a healthy diet and this supplement did not help one bit! I contacted customer support for a refund. They told me the refund was only for a three-month supply, not a one-month purchase. Their 90-day money back guarantee is false advertisement! Do NOT buy this product! It's a waste of hard-earned money!

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 5 People Have Voted

Posted on Jan 7, 2019

Misleading return policy. SCAM!

By Holly Z., Holland, MA, Verified Reviewer

I purchased a four-month supply, thinking if it didn’t work, no big deal I would get a refund. WRONG! The refund timeframe starts from when the product is delivered, which is great if you start it then. I contacted the company around 70 days of being on the product because it didn’t seem to be working for me (I thought the return policy was "return within 90 days for a refund"). I was told you have to use the product for 90 days BEFORE they will issue a refund. Ok, so I figured I would contact them again when I was finishing up my third bottle. Well, I missed a pill here and there and that added time to my third bottle, no biggie right? Yeah, well, since I didn’t start the bottles right away when I received them because I wanted to start on a specific day, that added to my time and when I contacted the company again after my "90 days," they informed me that the time frame for a return is after 90 days from delivery but before 120 days before delivery. I missed the 120 days by a little bit and was refused a refund.

You only have 30 days to contact them, hear back from them and arrange the return. SCAM. They don’t stand behind there product, and they make the return process really difficult and misleading. The first time I contacted them for a refund and was told I needed to be on it for 90 days they should have mentioned the 120-day cut off period. Instead they lead me to believe I had time. Crappy company. Crappy product. Crappy customer service.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 7 People Have Voted

Posted on Nov 4, 2018

Crap product, does nothing.

By Phil M., Rochester, NY, Verified Reviewer

Don't bother, save your money. I purchased a bottle and didn't lose anything. I watched my diet, got some exercise, more than usual, and there was no weight loss. I went to get my refund, but because I ordered and didn't start the plan for a few weeks after receiving it, I had surpassed the 30-day money back guarantee. That's kind of a crappy policy, that it has to be returned within 30 days of invoice date.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 4 People Have Voted

Posted on Oct 20, 2018

Horrible customer service

By Jake M., Dundee, Scotland, Verified Reviewer

I had ordered two boxes of Instant Knockout through PayPal and without asking for the delivery address it picked up the billing address, which is my home country. The same day I informed them of the mistake and they initially said that I had to reject the parcel from my home country. Later they said that they will have to wait for the shipment to return and only then will they deliver to my residence address.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 3 People Have Voted

Posted on Sep 25, 2018

This product doesn’t work, waste of money

By Isse Y., London, England, Verified Reviewer

It is a waste of money, it doesn’t work. Instead, I got heartburn and sleepless stress. When you call them, they will ignore you. Once they get their money, you will never get a refund. The 90 days refund is rubbish and a scam.

Be careful, don’t waste your time and money.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 6 People Have Voted

Posted on Aug 2, 2018

Expensive product, zero results

By Javier S., Raleigh, NC, Verified Reviewer

I was a one-time buyer. I think I ended up buying it deceived by the strong marketing campaign this product has. It's what you can see on the company's website. However, I realized the product does not work at all and I decided I would not buy it again.

The product is expensive in proportion with the amount, and last but not least, because you do not feel any of the benefits you are supposed to receive, like losing weight easier (it doesn't boost your energy levels either). I felt restlessness, anxiety and I could not sleep.

They didn't give me back what I paid for a product that caused me losses and bad health consequences, so that read thoroughly their policies if you want to take the risk.

I felt very disappointed about Instant Knockout, so I decided to share my experience with people interested in this product.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 8 People Have Voted

Posted on Jun 8, 2018

90-day guarantee is scam

By Angel G., Florida, Verified Reviewer

I bought this product thinking that I had nothing to lose. WRONG!

Some pieces of advice:

1) 90-day guarantee only applies to purchases of three boxes or more and they refund you everything minus $35 and whatever you have to pay in shipping.

2) It didn't do anything for me. I kept working out and eating right then added the pill and felt absolutely no change.

3) When you request a refund, they will ignore your first contact so be prepared to have to contact them again.

4) You can't call them because they are located in London and don't answer the phone.

5) The only thing they are guaranteeing is that they are making money whether you like the product or not.

Hopefully, this reaches enough people that it helps someone avoid the same pitfall I fell into.

Good luck.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 10 People Have Voted

Posted on Apr 28, 2018

Do not buy this junk

By Cody Bryan, Tampa, FL, Verified Reviewer

After ordering Instant Knockout, I waited until the next day to take the "recommended dose." After taking the four daily capsules, I became nauseous and had very bad heartburn and felt uneasy jittery. The next day I contacted only through email because there is no phone number for customer service. I was told by Joanne that per the company terms and conditions that I could not get a refund. She said it was "very clear" in the terms and conditions page.

Bottom line, do not order this product. It is nothing more than a scam to deceive you out of your money. She was no more concerned about my experience than the man in the moon. Save your hard earned money.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 8 People Have Voted

Posted on Feb 3, 2018

An honest review

By Patrick McCartney, Ireland, Verified Reviewer

Before buying this product, I searched and searched the internet for reviews, and of course, all I found were reviews on how amazing this product was. That was me SOLD. I was excited and could not wait until it arrived.

In fairness, I have only been taking the pills for about three weeks, but there is no difference. Nothing; "sweet Fanny Adams." I am overweight (19 stone) and need all the help I can get, and I was hoping this was something that could help me shift a few pounds as well as healthy eating and working out hard in the gym.

I promise you, don’t buy this product, it’s expensive nonsense. However, I will say that two weeks before buying Instant Knockout, I bought Roar Ambitions 4gauge pre-workout powder and it’s amazing. It does work. But as for Instant Knockout, it’s a hard lesson learned.

Bottom Line: No, I would not recommend this to a friend

Helpful Review? 19 People Have Voted
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