Instant Knockout Reviews: How Effective Is It? Formula, Pros, and Cons

Updated on March 11, 2024
Woman with weight loss pills and measuring tape at home, closeup

If you’re on a weight loss journey, you understand the challenges of shedding stubborn fat while preserving lean muscle mass. That’s where Instant Knockout comes in – a popular fat burner that claims to accelerate fat metabolism, boost energy levels, suppress appetite, and promote a toned physique.

But are these claims true, and what exactly makes Instant Knockout stand out in the crowded market of weight loss supplements?

Our review dives into its formula, breaking down the key ingredients and their intended benefits. We also examine potential side effects and user reviews, giving you a well-rounded view of what to expect.

What is Instant Knockout?

Instant Knockout is a weight loss supplement manufactured by Roar Ambition, a well-known fitness supplement brand in the UK. Initially developed for professional boxers and MMA fighters, Instant Knockout is now available for anyone looking to lose excess body fat.

The supplement is made with natural thermogenic ingredients and other essential nutrients to support fat-burning 24/7 while preserving muscle mass.

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How Does Instant Knockout Work?

Instant Knockout targets key functions in the body to facilitate weight loss and body composition management. Here’s a breakdown of how it works:

Firing Up Metabolism

The formula of Instant Knockout is designed to accelerate the thermogenic process in the body, which helps increase fat metabolism. By boosting your metabolic rate, Instant Knockout enables you to burn fat more efficiently without drastic changes to your diet or exercise routine.

Boosting Energy Levels

Sustaining energy levels is crucial during weight loss journeys, especially when following a calorie-restricted diet. Instant Knockout contains ingredients like caffeine and L-theanine, which not only enhance mood and cognitive function but also provide a sustainable energy boost. This allows you to maintain optimal performance during workouts and daily activities.

Curbing Appetite

One of the challenges of weight loss is controlling cravings and maintaining a calorie deficit. Instant Knockout includes Glucomannan, a dietary fiber that keeps you feeling full for longer, reducing the chances of unhealthy snacking and overeating. By curbing your appetite, Instant Knockout supports your weight loss goals.

Instant Knockout Ingredients

Instant Knockout is formulated with a powerful blend of nine natural ingredients, each carefully selected for its fat-burning properties. Here are the key ingredients in Instant Knockout:

  • 1800mg Glucomannan: Participants who took glucomannan experienced an average weight loss of 5.5 lbs over eight weeks, alongside significant reductions in serum cholesterol and LDL cholesterol [1].
  • 500mg Green Tea Extract: Analysis from two studies who took green tea showed a weight loss range of 0.6 to -1.6 kg, a BMI change of 0.2 to -0.5 kg/m^2, and a waist circumference reduction of 0.3 to -1.7 cm among 184 participants [2].
  • 300mg Caffeine Anhydrous: A meta-analysis of thirteen trials involving 606 participants indicated that caffeine intake could aid in reducing weight, BMI, and body fat [3].
  • 100mg L-Theanine: Mice treated with l-theanine (100 mg/kg/day) showed enhanced adaptive thermogenesis, browning of white adipose tissue, and increased energy expenditure [4].
  • 100mg Cayenne Powder: Subjects taking 4 mg of cayenne pepper showed a body fat percentage decrease of 5.91 percentage units more than those on placebo after 12 weeks [5].
  • 10mg Black Pepper Extract: Participants who took black pepper in a study demonstrated increased absorption of nutrients such as selenium, vitamin B complex, beta-carotene, and curcumin [6].
  • 45 mcg Vitamin D3: Obese subjects with vitamin D deficiency showed improved weight loss outcomes and reductions in fat mass when combining vitamin D supplementation with a weight loss diet [7].
  • 5mg Vitamin B6: A study suggested that vitamin B6 supplementation could help decrease BMI and improve body composition and obesity-related biochemical factors [8].
  • 10mcg Vitamin B12: Found to be negatively correlated with body mass index in studies linking low Vitamin B12 levels with obesity and overweight [9].

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Instant Knockout Benefits

While the manufacturer does not provide an official list of benefits, the formulation and user testimonials suggest several advantages of using Instant Knockout. Here are the key benefits you can expect:

Rapid Weight Loss

Instant Knockout’s thermogenic formula helps accelerate fat metabolism, leading to faster weight loss. Ingredients like green tea, caffeine, and B vitamins have been proven to enhance thermogenesis, resulting in increased calorie burning and fat loss.

Enhanced Athletic Performance

Hitting a plateau during your weight loss journey can be frustrating. Instant Knockout may help combat this by strengthening muscles, improving mood, and boosting physical endurance.

With increased energy levels and improved athletic performance, you can push yourself harder during workouts and achieve better results.

Smoother Cutting and Toning

Instant Knockout’s blend of nutrients supports fat burning and fulfills the body’s nutritional requirements. This could help you stay healthy and energized during the cutting phase when you’re reducing your calorie intake.

Increased Metabolism

Instant Knockout might stimulate thermogenesis, boosting your metabolism and helping you burn more calories throughout the day.

Appetite Control

The inclusion of glucomannan and other appetite-suppressing ingredients may help curb cravings and prevent overeating.

Enhanced Energy Levels

With its carefully selected ingredients, Instant Knockout provides a sustained energy boost that can improve your workouts and keep you motivated.

Improved Focus

The combination of caffeine and other stimulants in Instant Knockout can enhance mental clarity and focus, helping you stay on track with your fitness goals.

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Who Is Instant Knockout Best For?

Instant Knockout is best suited for individuals who are actively engaged in fitness, bodybuilding, or weight loss journeys and are looking for additional support in achieving their goals. Here are the key groups of people who may find Instant Knockout beneficial:

  • Athletes and Bodybuilders: Instant Knockout is designed to help individuals optimize their performance by supporting fat loss and providing an energy boost. Athletes and bodybuilders looking to enhance their physique and definition may find it useful.
  • Fitness Enthusiasts: People committed to regular exercise and fitness routines can use Instant Knockout as a supplement to support their weight loss and body composition goals.
  • Individuals on Weight Loss Journeys: If you are actively working towards losing weight and reducing body fat, Instant Knockout may aid in boosting metabolism and promoting fat burning.
  • Adults in Good Health: Instant Knockout is suitable for adults in good health who are seeking to optimize their overall well-being and physical performance. Its natural formulation provides an effective means of supporting metabolic health and energy levels.

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Who Should Avoid Taking Instant Knockout?

Instant Knockout may not be suitable for everyone. Individuals in the following categories should consider avoiding or consulting a healthcare professional before using Instant Knockout:

  • Pregnant or Nursing Women: Women who are pregnant or breastfeeding should avoid using Instant Knockout, as the safety of certain ingredients during these periods is not well-established.
  • Individuals Under 18 Years: The product is formulated for adults, and individuals under 18 should avoid using it as their nutritional and energy needs may differ.
  • Those with Medical Conditions: Individuals with pre-existing medical conditions, especially those related to heart health, high blood pressure, or sensitivity to stimulants, should consult a healthcare professional before using Instant Knockout.
  • Sensitivity to Caffeine: People who are highly sensitive to caffeine should be cautious, as Instant Knockout contains caffeine from natural sources. Excessive caffeine intake can lead to side effects like jitteriness and insomnia.
  • Allergies or Sensitivities: Individuals with known allergies or sensitivities to any of the ingredients in Instant Knockout should avoid its use.
  • Medication Interactions: Those taking prescription medications, especially for conditions like hypertension or thyroid disorders, should consult a healthcare provider to ensure there are no potential interactions with the supplement.

Instant Knockout Customer Reviews

Before investing in any of the best weight loss supplements, it’s always helpful to hear from those who have already tried it. Instant Knockout has received positive feedback from many customers who have experienced significant results.

Users have reported increased energy levels, reduced appetite, and noticeable fat loss. These testimonials highlight the effectiveness of Instant Knockout when combined with a proper diet and exercise regimen.

Real customers have shared their positive experiences with Instant Knockout. Here are a few testimonials from users:

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Fabio Passos started CrossFit a year ago to get in shape. After finding Instant Knockout online, he tried it and saw significant improvements within a month. He continues using it four times daily, now in the best shape of his life at 41. Passos highly recommends Instant Knockout for rapid fitness results.

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AYB from Hungary shared their positive experience with Instant KO Cut. Initially skeptical, they noticed increased definition and appetite suppression within two weeks of use. Despite previous struggles with cravings, Instant KO Cut effectively curbed their appetite. With a healthy diet and regular exercise, AYB achieved their fat loss goals.

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Dosage: How to Use Instant Knockout for Best Results

To achieve the best results with Instant Knockout, it is recommended to take four capsules spread throughout the day. It is advised to take one capsule in the morning, before lunch, one in the afternoon, and before your evening meal

This dosage ensures that your body consistently receives the active ingredients, maximizing their effects on metabolism, appetite suppression, and energy levels. Additionally, combining Instant Knockout with a balanced diet and regular exercise routine will further enhance your fat-loss journey.

Potential Side Effects of Instant Knockout

Instant Knockout claims to be well-tolerated due to its 100% natural and transparent formula. However, you may still experience mild side effects, like nausea, headache, or stomach ache, especially when starting a new fat burner.

It is always recommended to monitor your body’s response and consult a healthcare professional if you have any concerns.

Where to Buy Instant Knockout

Instant Knockout is available for purchase on its official website. While you may find it on third-party websites like Amazon, it is recommended to buy directly from the official website. This is to ensure the authenticity and quality of the supplement.

The official website offers various packages, including discounts, free shipping, and additional bottles, depending on your purchase.

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FAQs on Instant knockout

Here are answers to a few commonly asked questions regarding Instant Knockout:

Can Both Men and Women Use Instant Knockout Effectively?

Instant Knockout is designed for both men and women. Its formulation aims to support fat burning and enhance energy, making it suitable for individuals of any gender engaged in fitness and weight loss journeys.

Where Is the Best Place to Purchase Instant Knockout?

For authenticity and quality assurance, it is recommended to purchase Instant Knockout directly from the official website. This ensures that you receive a genuine product and can take advantage of any special offers or guarantees provided by the manufacturer.

What Results Can Be Expected From Using Instant Knockout and in What Timeframe?

Results may vary, but users often report increased energy levels, improved metabolism, and enhanced fat loss when using Instant Knockout. The timeframe for noticeable results can depend on factors such as individual metabolism, diet, and exercise routine. Consistent use, coupled with a healthy lifestyle, is key.

How Effective Is Instant Knockout for Fat Burning?

Instant Knockout contains ingredients known for their potential to boost metabolism and promote fat burning. Many users find it effective in supporting their weight loss goals, especially when combined with regular exercise and a balanced diet.

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How Much Caffeine Is Contained in Instant Knockout, and What Are the Implications?

Instant Knockout contains caffeine from natural sources like green tea extract. The exact amount is not disclosed but is formulated to provide an energy boost without excessive stimulation. Individuals sensitive to caffeine should be mindful of their overall daily intake.

How Long Does Instant Knockout Take to Work?

The time it takes to experience the full effects of Instant Knockout can vary. Some users report increased energy shortly after consumption. Others report noticeable changes in body composition may take weeks or months, depending on factors like diet and exercise.

Is Instant Knockout Legit?

Yes, Instant Knockout is a legitimate product designed to support fat loss and enhance energy levels. It is produced by a reputable company and has gained popularity within the fitness community.

Is Instant Knockout FDA Approved?

Instant Knockout is among the best OTC weight loss supplements, and FDA approval is not mandatory for such products. However, it is manufactured in FDA-approved facilities, ensuring quality and adherence to the Current Good Manufacturing Practice (CGMP) regulations.


After a thorough analysis of Instant Knockout, it is evident that this fat burner offers promising results. With its natural composition, Instant Knockout helps accelerate fat metabolism, boost energy levels, and suppress appetite. 

The combination of ingredients supports weight loss, enhances athletic performance, and promotes a toned physique. However, as with any supplement, it is essential to listen to your body and consult a healthcare professional before starting any new regimen.

Remember, weight loss is a journey that requires commitment, a balanced diet, regular exercise, and a holistic approach.

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  1. Walsh, D. E., et al. “Effect of Glucomannan on Obese Patients: A Clinical Study.” International Journal of Obesity, vol. 8, no. 4, 1984, pp. 289–293,
  2. Rogers, James, et al. “Capsaicinoids Supplementation Decreases Percent Body Fat and Fat Mass: Adjustment Using Covariates in a Post Hoc Analysis.” BMC Obesity, vol. 5, 2018, p. 22, doi:10.1186/s40608-018-0197-1.
  3. Jurgens, Tannis M., et al. “Green Tea for Weight Loss and Weight Maintenance in Overweight or Obese Adults.” Cochrane Database of Systematic Reviews, vol. 12, no. 12, 2012, p. CD008650, doi:10.1002/14651858.CD008650.pub2.
  4. Khalaf, N. A., et al. “Antioxidant Activity of Some Common Plants.” Turkish Journal of Biology, vol. 32, no. 1, 2008, pp. 51–55,
  5. Tabrizi, Reza, et al. “The Effects of Caffeine Intake on Weight Loss: A Systematic Review and Dos-Response Meta-Analysis of Randomized Controlled Trials.” Critical Reviews in Food Science and Nutrition, vol. 59, no. 16, 2019, pp. 2688–2696, doi:10.1080/10408398.2018.1507996.
  6. Peng, Wan-Qiu, et al. “L-Theanine Activates the Browning of White Adipose Tissue through the AMPK/α-Ketoglutarate/Prdm16 Axis and Ameliorates Diet-Induced Obesity in Mice.” Diabetes, vol. 70, no. 7, 2021, pp. 1458–1472, doi:10.2337/db20-1210.
  7. Mason, Caitlin, et al. “Vitamin D3 Supplementation during Weight Loss: A Double-Blind Randomized Controlled Trial.” The American Journal of Clinical Nutrition, vol. 99, no. 5, 2014, pp. 1015–1025, doi:10.3945/ajcn.113.073734.
  8. Haidari, Fatemeh, et al. “The Effect of Pyridoxine Hydrochloride Supplementation on Leptin, Adiponectin, Glycemic Indices, and Anthropometric Indices in Obese and Overweight Women.” Clinical Nutrition Research, vol. 10, no. 3, 2021, pp. 230–242, doi:10.7762/cnr.2021.10.3.230.
  9. Baltaci, Davut, et al. “Association of Vitamin B12 with Obesity, Overweight, Insulin Resistance and Metabolic Syndrome, and Body Fat Composition; Primary Care-Based Study.” Medicinski Glasnik: Official Publication of the Medical Association of Zenica-Doboj Canton, Bosnia and Herzegovina, vol. 10, no. 2, 2013, pp. 203–210,

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Leonard M. Moore

Leonard is a registered dietitian fueled by a profound passion for both nutrition and writing. With a strong background in dietetics, he blends his expertise with his creative flair to craft engaging and informative content.