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Instant Knockout

Instant Knockout

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25 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 25 Reviews
5 Star:0% 4 Star:8% 3 Star:4% 2 Star:0% 1 Star:88%
16% Recommend This Company
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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

Posted on May 31, 2017

Worst fat burner ever, plus refund lie

By Marie Lacour, Houston, TX, Verified Reviewer

I am a professional fitness enthusiast. I have taken fat burners, amongst other supplements many times over the years, cycling as needed. I must say, this product had zero effect. In fact, I gained weight and fat while taking this product on a strict diet. I contacted the Instant Knockout company customer service and was told refunds are only issued within 30 days of purchase. The 90-day satisfaction guarantee is a lie.

I am looking into proceeding with a lawsuit against the company for false statements. Feel free to contact me if you have any questions.

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

Helpful Review? 18 People Have Voted

Posted on Aug 19, 2016


By Sean M, San Francisco, CA, Verified Reviewer

Don't waste your time! I tried Instant Knockout for a week and, because of its extreme amount of caffeine, I felt continuously dizzy and lightheaded. Very unhealthy feeling.

Then, to top it off, as the review states above, the "refund" policy is a total lie. There are so many hoops involved taht you'll never meet their criteria for a refund. I would love to know how many refunds they've actually given. My guess is ZERO! Save your money.

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

Helpful Review? 15 People Have Voted

Posted on Jun 27, 2017

Lies! Product doesn't work, and false refund "guarantee"

By J D, Australia, Verified Reviewer

It is a waste of time and money, with a false advertisement of "hassle free 90-day money back guarantee." I have been given the runaround. I sent the unused products back (registered post cost me $35 Australian) and won't be given a refund because I didn't send the empty bottles (who knew you had to keep empty bottles).

I took this product for three months with healthy eating and three boot camp sessions a week. It didn't have any affect at all! Three kg in three months is a joke considering my BMI equals obese.

Not happy at all, and the company is a joke! Avoid at all costs.

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

Helpful Review? 15 People Have Voted

Posted on Jan 22, 2016

So far so good

By Michael Heavey, Dublin, Ireland, Verified Reviewer

Having been through a sedentary period over the last few months I recently decided to get back to a more active lifestyle and to shed the 14 lbs or so of unwanted weight that I have accumulated.

I was particularly anxious to ensure that any weight loss is limited to fat and that muscle tone and mass remain unaffected. Previous experience has taught me that this is easier said than done. With that in mind, having researched different products, I purchased a one month's supply of Instant Knockout. As an MMA fan I was persuaded by the endorsement of the great trainer Greg Jackson of JacksonWink gym.

I took claims of increased energy and appetite suppression with a pinch of salt. My only hope and expectation was fat reduction and muscle mass retention.

Thus far, the product has met my expectations. I am losing 3-4lbs per week and am happy that muscle mass appears unaffected.

I was pleasantly surprised that the appetite suppression claim seems to be accurate although I accept this may well be a placebo effect from my generally positive reaction to the product to date.

As my one month supply is now running out I was on the point of ordering another month's supply when I came across this site and the reviews. They give me pause for thought but, in truth, since my experience has been a positive I will probably go ahead and make the order. I will have achieved my target already but I would like to have a bottle on hand in the event I need to do this again in the future.

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

Helpful Review? 14 People Have Voted

Posted on Jul 13, 2016

Another failed promise

By KNovell, Jacksonville, FL, Verified Reviewer

I am totally dissatisfied with the product. I recently ordered 2 bottles, used as directed, worked out regularly and even ordered two different Paleo meal plans to be sure I stayed on track. I experienced absolutely NO RESULTS except feeling that I was eating cleaner.

Totally disappointed again with this and other weight loss pills. I'm questioning whether the outcome of the 90 day guarantee and if that's even legit.

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

Helpful Review? 14 People Have Voted

Posted on Jul 31, 2016


By Ryan, CT, Verified Reviewer

Complete rip off. No added benefits other than having to pee 10 times a day and throughout the night. Returned the product after 90 days and they are refusing to offer a refund because I did not return the free items. Dispute opened with AMEX. Avoid this product and company at all costs!

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

Helpful Review? 14 People Have Voted

Posted on Apr 20, 2017

Worst customer service ever

By Mok, Paris, France, Verified Reviewer

I ordered on March 8th, and I still didn't receive my package. The first package was sent back to U.K. for "unknown reasons." The customer service representative said I have to contact the carrier to know the reason of this nondelivery. Me, the customer paying for the delivery? I couldn't believe it. Then it took a week for the company to send another package, which now has been lost.

I have no feedback from them, no excuses, no compensation and now no answers. They killed my plans, as I'm following a program and needed this product, and I'm going on holidays in two weeks. You should avoid this company, I mean it. I asked for a refund but received no answers from them after multiples emails. Apparently, they have enough customers to ignore you when something wrong happens; I hate that.

Luckily, I used PayPal, and I'll claim a refund directly from them. I ordered another product which has very good reviews from "transparent labs."

Even if I didn't try the product, Instant Knockout does not deserve a single star. Go away from this company!

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

Helpful Review? 14 People Have Voted

Posted on Feb 13, 2016

Waste of money

By Sam, Memphis, TN, Verified Reviewer

All what you read above are true, this is a complete waste of money. I saw no energy boost what so ever and my appetite is exactly the same....trust me don't waste your money.

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

Helpful Review? 13 People Have Voted

Posted on Jul 30, 2016

Does not work - refund scam.

By Rachel, Fort Worth, TX, Verified Reviewer

Does not work! Maintained healthy eating and daily workouts, nothing. Then because I threw away my empty bottles I can't get my money back. I will be more than happy to share my horrible experience with EVERYONE I come in contact with, that their associate insinuated that if you didn't keep your trash bottles then you have sold the product. Absurd.

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

Helpful Review? 13 People Have Voted

Posted on Feb 7, 2017

Please be careful

By Mary, County Fermanagh, Ireland, Verified Reviewer

Please be careful, this product does not do what it says, and neither does the company.

These made me feel sick, jittery and very anxious. When I emailed the company, I received a reply that basically said: "tough, unless you continue to take it for 90 days, get lost."

Please be aware that you are buying something that can have bad side effects and doesn't work. Roar Ambition is a suitable name. They're ambitious and don't care about people's health, and they "roar" that they will only give you money back if you continue to take a product that makes you ill.

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

Helpful Review? 13 People Have Voted
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