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Instant Knockout Reviews: Do you need this fat-fighter in your corner?

This thermogenic fat burner sports a handful of well-researched natural ingredients. But is it safe and effective enough to be worth a try?

Last Updated: Jan 2, 2023
Instant Knockout

More Americans than ever are trying to lose weight these days. A solid 50% of the population tried to lose weight last year. You’re not alone if you were among them and didn’t see any changes in the mirror despite your best efforts.

Recent findings show that body composition is more complex than calories in and out — or even following a strict exercise plan. The path to progress isn’t always clear, leading many to seek supplements or meal replacements to help. Instant Knockout is one such supplement brand.

In this review, we’ll do a deep dive into the ingredients and the science behind them to help you decide if Instant Knockout is the supplement for you.

Review Summary


  • All-natural ingredients list
  • Increased energy and athletic performance
  • Vegan-friendly
  • Convenient system option using Cut + Complete
  • Buy a 3-month supply and get 1 month free


  • Fairly high caffeine content in Cut
  • Complete is more expensive than similar protein powders
  • No money-back guarantee

Bottom line

Instant Knockout can provide a helping hand as part of a weight-loss strategy that already includes a healthy diet and regular exercise. It will likely work best as a short-term boost to help you deal with stubborn fat or lose weight quickly.

Our Top Picks

Instant Knockout

Instant Knockout is a useful tool for those looking to cut fat while retaining lean muscle.

This all-natural, vegan-friendly supplement can help you burn fat and increase your energy and performance. Keep in mind that best results also combine a balanced diet and exercise regimen.

Instant Knockout Cut
Reviewed by Innerbody Research
Instant Knockout Complete
Reviewed by Innerbody Research
Instant Knockout System
Reviewed by Innerbody Research

Why you should trust us

Over the past two decades, Innerbody Research has helped tens of millions of readers make more informed decisions involving staying healthy and living healthier lifestyles.

We extensively test each health service or product we review. We try our best to give you, our readers, an unbiased exploration of at-home health options, free of marketing jargon or gimmicks. We evaluate products and services based on their adherence to quality, the latest medical evidence and health standards, and a simple question: would we buy Instant Knockout or service ourselves if it weren’t part of our job, and would we recommend it to family and friends?

Additionally, like all health-related content on this website, this review was thoroughly vetted by one or more members of our Medical Review Board for accuracy.

What is Instant Knockout?

Instant Knockout is part of Roar Ambition’s broader supplement lineup. The product came about to meet the demands of MMA fighters trying to make weight at rapidly approaching weigh-ins. Instant Knockout has two products that you can purchase separately or use as a system to help you lose weight:

Cut may help you lose weight by raising your metabolism, making trips to the gym seem easier, and fat loss more effortless. And it may suppress your appetite to help you avoid overeating. Complete is a high-quality protein powder created with real food sources that pair well with Cut.

Instant Knockout Cut

Cut is Instant Knockout’s weight loss supplement. It contains nine ingredients to fight stubborn fat that doesn’t budge with diet and exercise. It does this by naturally suppressing your appetite and boosting your metabolism to burn more calories.

Its original purpose was to help pro fighters lose weight quickly when weigh-ins were approaching. But the site promises Cut is an effective product to use in a sustainable weight loss plan.

Let’s see how true that claim is by first looking at Cut’s ingredient list to learn how it works.

Vitamin D3 (1,800 IU)

Vitamin D is essential for healthy bones and has a part in many metabolic processes. If you’re like the 41% of Americans with a deficiency, adding vitamin D could help with weight loss. One clinical study found women given 1,000 IU of vitamin D daily lost six times as much weight as a placebo group. Another study found no significant difference between women given 2,000 IU daily versus a placebo group.

Vitamin B6 (5 mg)

Vitamin B6 is a significant mood regulator. It helps create neurotransmitters like serotonin and dopamine. This can help prevent depression and give you a more stable mood if you lack B6. If a depressed mood leads you to eat more, you’ll have a harder time losing weight (a theory backed by this clinical study.) Another study found overweight women with a diet rich in B6 had more success maintaining weight loss.

Vitamin B12 (400 IU)

Vitamin B12 is linked with energy production and mood. If you’re B12-deficient, taking a supplement can help raise energy levels, giving you a boost during workouts too. The link isn’t clear yet, but this clinical study found a correlation between obesity and B12 deficiency. It also showed a negative correlation between B12 and body mass index (BMI).

Caffeine (300 mg)

Caffeine has a lot of effects beyond getting your morning started with a jolt. One clinical review showed higher athletic performance across a range of sports, including endurance and high-intensity activities. Another caffeine study showed higher caffeine intake correlated to weight loss, weight management, and smaller waistlines. Keep in mind the amount in a daily serving of Cut is the equivalent of about 3-4 cups of coffee. Be careful if you’re sensitive to caffeine.

L-Theanine (100 mg)

L-theanine is caffeine’s partner in health. When paired, L-theanine creates a sense of focus and can reduce any anxiety caused by caffeine. According to this clinical study, you may experience increased cognitive function and less stress. One animal study found that l-theanine suppressed fat accumulation and weight increases in mice.

Green Tea Extract (500 mg)

Green tea boasts plenty of benefits like keeping skin healthy, being rich in antioxidants, and protecting your brain’s health. Thanks to two components (green tea catechins and caffeine), green tea extract might help with weight loss, too. A clinical study found a connection between green tea consumption and weight loss.

Cayenne Pepper (100 mg)

Capsaicin, a compound that creates a spicy sensation in peppers, brings a host of health benefits. According to this clinical study, it has use as a weight loss and anti-obesity aid. Capsaicin helps you regulate your appetite by giving you a feeling of fullness sooner. You may also spend slightly more energy (even at rest), allowing you to burn more calories.

Black Pepper Extract (10 mg)

Black pepper contains a compound called piperine, the key to this additions’ purported health benefits. Researchers have studied piperine to measure benefits like nutrient absorption and encouraging healthy digestion. But, one animal study showed reductions in fat mass, body weight, and cholesterol in rats. The dosage was much higher than the contents of Cut (40 mg/kg of weight). So how effective black pepper can be in humans remains uncertain.

Glucomannan (1,800 mg)

Glucomannan is an extract from the roots of the konjac plant, popular in east and southeast Asian cooking. Though glucomannan has some popularity as a weight-loss supplement, results on its effectiveness are conflicting. One clinical study found no difference in weight loss between subjects taking 4,000mg of glucomannan daily and a placebo group. Another study found a loss of 5.5lbs on average over an 8-week trial. The good news is glucomannan was well tolerated in all studies and should be safe for most people.

Does Instant Knockout Cut work?

Like all supplements, Instant Knockout Cut can provide widely varying results for different people. But most people who try Instant Knockout will experience effects to help them meet their goals. You can expect to feel more energy and some appetite suppression. These, in turn, help you to power through to your goals. So don’t expect the pounds to melt off by themselves. Cut helps you do the work necessary to meet your goals.

Who should try Instant Knockout Cut?

People looking for a short-term boost in weight loss or energy would benefit most from trying Cut. Thanks to their hefty caffeine content, the ingredients should give you a performance boost in the gym (both from natural caffeine and green tea extract). That also means people who already lead an active lifestyle might benefit most.

Anyone deficient in vitamins D3, B6, or B12 will experience better results too. So a trip to the doctor to check your levels is recommended.

You can also take vitamin and mineral tests from various at-home testing companies. Innerbody readers get exclusive discount codes for vitamin tests through these companies:

Instant Knockout Complete

Instant Knockout Complete is a protein powder and meal replacement. They’ve designed Complete to work in tandem with Cut using food-based protein in a low-calorie package. The idea is to make weight loss as easy as possible by pairing Cut with one meal that makes you feel full while including essential nutrients to keep you going strong.

Each serving includes 35 g of protein, 35 g of carbs, and 13 g of dietary fiber in 400 calories.

Check out the full ingredients list below.

Plant Proteins

Instant Knockout Complete uses soy and peas to provide 35 g of protein per serving. Plant-based proteins like these may be gentler on your stomach and cause less bloating than a traditional whey protein powder.

Golden Flax and Chia Seeds

Flaxseed is a nutrient-packed, fiber-rich addition to Complete’s formula. Besides being a low-calorie source for essential vitamins, flaxseed may help you lose weight. A clinical study of 45 women resulted in significant weight loss and reduced belly fat.

Similar to flax, chia seeds contain healthy fats, protein, fiber, and other nutrients in a low-calorie package.


MCT stands for medium-chain triglycerides. But don’t be fooled by the scientific name. Most companies naturally source MCT from coconuts. MCTs may offer benefits like improved brain health, appetite control, and weight loss, and one clinical study found potential for MCT in maintaining weight loss.

Oat Flour

Oat flour is a healthy source of carbs, superior to common bread and rice. Each carbohydrate falls on a scale called the glycemic index (GI). Foods with a high GI change your blood sugar levels quickly. High GI levels cause the energy crash you may experience after a big bowl of pasta. Oat flour has a very low GI, avoiding these crashes (a score of about 37 compared to 50+ for typical bread and rice).

Organic Brown Rice

Organic brown rice is one more alternative to protein isolates packed with nutritional value. A clinical study found that brown rice contains enough essential amino acids and branched-chain amino acids (BCAAs) to work in place of other protein sources.

Does Instant Knockout Complete work?

Instant Knockout Complete works well as a meal replacement thanks to its formulation based on real-food sources. You’ll get a low-cal shake that’s loaded with essential nutrients to keep you moving and may lower your overall calorie intake. But everything that happens between your meals is important, too. Ordering Complete with Cut can make calorie counting convenient and easy, but it won’t do the hard work for you.

Who should use Instant Knockout Complete?

Anyone wanting the convenience of a weight loss supplement packaged with a matching meal replacement should consider adding Instant Knockout Complete to their order. Its list of all-natural, vegan-friendly ingredients is loaded with an impressive 35 mg of protein, 35 mg of carbs, 13 mg of fiber, and a ton of vital nutrients in a low-cal package.

That said, it’s a lot more expensive than similar protein powders, making Complete feel like a luxury more than an essential. If you don’t mind shopping around a bit or already have your favorite protein powder, you might want to skip Complete.

Instant Knockout pricing

Instant Knockout’s pricing is pretty straightforward. You can get a single order of either Cut or Complete for $65, but comparing costs can get tricky when you consider that one order of Cut lasts 30 days, and one order of Complete only lasts 14. To make it easier, take a look at this handy price breakdown:

Instant Knockout Cut

Instant Knockout Cut is available in 1, 2, and 3-month supplies. When you order the 3-month supply, the company includes a fourth bottle for free, bringing down the price per serving.

  Cost Cost per bottle Cost per serving
One bottle $65 $65 $2.17
Two bottles $130 $65 $2.17
Four bottles $195 $48.75 $1.63

Instant Knockout Complete

Instant Knockout Complete is available in 1-, 2-, and 3-bag quantities. There are no extra bags and no savings introduced as the size of your order increases.

  Cost Cost per bottle Cost per serving
One bag $65 $65 $4.64
Two bags $130 $65 $4.64
Three bottles $195 $65 $4.64

Instant Knockout System

The Instant Knockout System includes both Instant Knockout Cut and Instant Knockout Complete in a 1- or 2-month supply. Because each supply comes with 30 pills and 28 meals per month, we split the difference and calculated the cost per day by 29 days.

  Cost Cost per day
One-month supply $195 $6.72
Two-month supply $375 $6.47

If you’re still feeling confused, we don’t blame you. One thing we’d love to see Instant Knockout fix is their serving allotment. There’s no reason they should sell a 28-day supply of meals alongside a 30-day supply of pills. Simply increasing the serving count in Complete by two meals would make it easier to manage your weight loss supplies.

HSA, FSA, and health insurance

Instant Knockout’s supplements are not applicable for HSA, FSA, or health insurance.

Shipping from Instant Knockout

Instant Knockout offers free shipping on US-based orders over $90. If your order comes in under $90, you’ll pay $8.95 for USPS priority post.

Is Instant Knockout a good value?

Compared to many fat burners out there, Instant Knockout Cut is a good value. The price is similar to a lot of weight loss supplements. But, where other products lack any scientific backing, Cut doesn’t. The natural ingredients and safety could make Cut one part of a short-term weight loss strategy driven by intense exercise.

Is Instant Knockout safe?

It’s tough to recommend Cut as part of a long-term weight loss plan because of the heavy caffeine content. We count the total at about 340 mg per serving, counting green tea extract. That’s within safe levels, but not by much (under 400 mg is ideal).

Overuse of caffeine could cause some adverse side effects like anxiety, cardiovascular problems, and disrupted sleep patterns. If you experience jitters, nervousness, or irritability, caffeine could be to blame.

Instead, try Cut if you’re planning a short period of intense weight loss. Follow this with a healthy diet and exercise regimen to maintain your loss afterward.

Besides that, Complete’s food-based approach to protein powders should prove safe for nearly anyone.

How we evaluate health services

At Innerbody Research, we customize our evaluation criteria depending on the type and nature of the health-related service or product. But in general for health products and services, we have five broad areas that we explore in our evaluations, including:

Quality: How well does the company deliver its core service(s) to the customer? For testing services, does the company adhere to the latest and most advanced testing technologies and achieve a very high degree of accuracy? For non-testing telemedical or teletherapy services, is the quality of the service high enough that we would recommend it to loved ones without hesitation? If not, why not? For health products, does the product or device meet a high level of safety? Is it manufactured with high-quality standards? Has it – or have its ingredients – been subjected to studies that confirm effectiveness?

User-friendly: How intuitive and convenient is the service or product? Does the device, program, app, or website achieve a good degree of user-friendliness for its customers?

Value: Are you getting your money’s worth? Are there any hidden costs or charges? Does the company offer discounts?

Privacy: If health data is stored, will your data be stored securely? Are payments secure? Does a company market your information?

Customer support: Particularly in situations where ‘one size fits all’ doesn’t make sense, how well does the company help to make the service or product ideal for you or address your individual needs?

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