Instant fixes. There is no scarcity of purportedly magical solutions out there for fat loss. Yet, no product can deliver overnight success. There is no substitute for proper exercise and a good diet when it comes to weight loss. That said, fat burners can be an important ally along your weight loss journey. They ensure your exercise and nutrition inputs go further. But all fat burners are not the same. 

As two of the better known brands in the fat loss space, Leanbean and Instant Knockout have proven to be among the more effective fat burners in the market. Still, they do not contain identical ingredients in identical quantities so they will not have an identical effect. Which of the two is better? We take a look at the attributes of each while comparing pros and cons to see which one comes out on top.

What is Leanbean?

Made with women in mind, Leanbean is a fat burner that incinerates excess body fat, suppresses appetite and drives natural metabolism. It improves your focus and lifts your energy levels during your gym time to ensure you achieve your envisioned shape and weight faster. 

Leanbean is grounded on a meticulously selected set of all-natural ingredients that speed up your weight loss while protecting you from weight loss deficiencies.


Ultimate Life Limited is a UK-based wellness and weight loss brand that was founded in 2015. Despite a narrow product range, the company has built a reputation for manufacturing effective weight management products for women that have been well received in the marketplace. Other than Leanbean, Ultimate Life also makes Powher.

Leanbean Key Features

  • Incinerate excess body fat.
  • Block hunger pangs and cravings.
  • Protect from weight loss deficiencies.




What is Instant Knockout?

It’s not always easy to tell what a supplement can do from looking at its name alone. That’s not the case for Instant Knockout though. Also known as Instant Knockout Cut, this fat burner was originally made for the world class athlete.

It has stuck to its sporting roots in the delivery of quick fat loss results. That does not exclude the average fat loss enthusiast from tapping into its capabilities.

Instant Knockout doesn't just help you lose weight but also has the ability to sculpt the muscles of your abs, pectorals, legs and arms. It speeds up your metabolism by precipitating an energy shortfall that draws on the breakdown of stored fat to meet the energy need. Instant Knockout strengthens the impact of the time and effort you put into the gym thereby propelling you to the physique you want, faster.


Roar Ambition is a UK sports supplements company whose range of products are designed to deliver better weight, strength, fitness, speed, focus and overall health. Founded in 2012, it is run by seasoned Internet marketers. Other Roar Ambition products include TestoFuel, Hunter Burn, Prime Male, Hourglass Fit, Hunter Test and Hunter Focus.

Instant Knockout Key Features

  • Incinerate excess body fat.
  • Block hunger pangs.
  • Sculpts muscles.





Common Ingredients



Instant Knockout


Small quantities within the 50 mg green coffee extract

300 mg per daily serve

Vitamin B6

1.7 mg per daily serve

5 mg per daily serve

Vitamin B12

2.4 mcg per daily serve

10 mcg per daily serve


3000 mg per daily serve

1800 mg per daily serve

Black pepper

5 mg per daily serve

10 mg per daily serve

Note on ingredient quantities

Leanbean’s and Instant Knockout’s supplement facts sheet do not characterize their ingredient servings in the same way. An initial glance at the two sheets would appear to show Instant Knockout exceeds Leanbean on every shared ingredient.

However, Leanbean refers to one serving as two pills. Yet, the manufacturer recommends you take two pills three times daily. Instant Knockout refers to single servings of four pills which is the total number of pills you should take per day. Except in this case it is one pill four times a day. 

So for a like for like comparison of daily servings, it is necessary to convert each stated ingredient to the true uptake per day. In this case, we multiplied Leanbean’s listed quantities by three when populating the table above. 

Other than their shared components, the two product’s ingredients are markedly different.

Unique Ingredients in Leanbean

  • Garcinia cambogia –  Suppresses appetite.
  • Green coffee – Continues chlorogenic acid and other antioxidants.
  • Turmeric – A milder stimulant alternative to caffeine that is  thermogenic and contains an antioxidant.
  • Acai berry – Rich in antioxidants and suppresses appetite.
  • Zinc – Boosts immunity, lowers inflammation, facilitates protein synthesis and contributes to fat and carb metabolism.
  • Choline –  Facilitates metabolism of excess fat, the transportation of fat cells as well as the removal of unhealthy cholesterol.
  • Chloride – Aids the digestion process and supports production of the stomach’s hydrochloric acid.
  • Chromium – Supports healthy metabolism of major nutrients and the optimization of blood sugar.

Unique ingredients in Instant Knockout

  • Vitamin D3 – Improves fat loss, maintains muscle mass, boosts skeletal strength and supports cardiovascular system health.
  • Green tea – Contains catechins that accelerate the burning of excess fat.
  • Cayenne pepper – Slashes excess weight and suppresses appetite.
  • L-theanine – Supports fat loss, improves focus, boosts immunity and lowers cardiovascular risk and strengthens natural immunity.

Side Effects

Both Leanbean and Instant Knockout are made from research-backed ingredients. Neither has known side effects as long as the supplement is taken as per the correct dosage. 

Instant Knockout does contain substantial amounts of caffeine. Though the quantity is within safe range for daily consumption, it may negatively affect individuals that are caffeine-sensitive. Signs of caffeine toxicity include sleeplessness, seizures, restlessness, irregular heart rate, hormonal imbalance, headaches, dizziness and anxiety. 

When taking Instant Knockout, it is recommended that you reduce your intake of caffeinated beverages especially if you are caffeine sensitive. If you experience signs of caffeine toxicity after you start using Instant Knockout, stop immediately. 

Irrespective of the fat burner you go with, consult your doctor first to confirm you are in the clear. This is particularly important if you are breastfeeding, pregnant, are on medication or have been diagnosed with a long term health condition.

Price and Offers


180 pills - 30 days


  • Discounts on bulk orders.
  • Free shipping on most orders.
  • 90-day money back guarantee.

Instant Knockout

120 pills - 30 days


  • Discounts on bulk orders.
  • Free shipping on most orders.
  • 90-day money back guarantee.

Price-wise and offers-wise, the two products are evenly matched.

Pros and Cons



  • Stimulates metabolism and incinerates excess body fat.
  • Blocks hunger pangs.
  • Enhances activity focus and boosts workout energy.
  • Protects from weight loss deficiencies.
  • Produced in facilities that satisfy BRC, FDA and GMP requirements.
  • Vegan and vegetarian friendly. Also contains no gluten.


  • Made with women in mind so may not deliver the same fat loss benefits in men.
  • For best results, pair Leanbean with an appropriate exercise and diet regimen.

Instant Knockout


  • Incinerates excess body fat by speeding up metabolism thereby precipitating an energy shortfall.
  • Blocks hunger pangs.
  • Sculpts abs, pectorals, legs and arms muscles.
  • Boosts energy during and after intense exercise sessions.
  • Produced in facilities that satisfy FDA and cGMP requirements.
  • Vegan and vegetarian diet friendly.


  • Contains high amounts of caffeine. For caffeine sensitive persons, this may mean experiencing one or more symptoms of caffeine toxicity such as sleeplessness, seizures, restlessness, irregular heart rate, hormonal imbalance, headaches, dizziness and anxiety.
  • For best results, pair Instant Knockout with an appropriate exercise and diet regimen.

Final Verdict

There is no guarantee that just because a friend or relative experienced remarkable success using a particular fat burner that you will enjoy the same. Differences in each individual’s chemical composition, physiological process, health, weight and lifestyle implies no two people will experience identical results. 

Still, one product will always have an edge if you run an objective comparison of any two fat burners. In this case, Leanbean does come across as the overall better supplement.

First, it contains miniscule quantities of caffeine compared to Instant Knockout. Caffeine can have unpleasant effects in sensitive individuals. This includes sleeplessness, seizures, restlessness, irregular heart rate, hormonal imbalance, headaches, dizziness and anxiety. Leanbean instead goes for the caffeine-thin green coffee and the milder stimulant turmeric.

Second, while Leanbean contains less vitamin B6 and vitamin B12 than Instant Knockout, it does have a much higher amount of the powerful weight loss ingredient glucomannan. Glucomannan is a soluble fiber that serves an appetite suppressant.

Editor's Choice: Leanbean




About the author 

Tim Rockwell

As a certified fitness instructor and health coach, I have helped countless people lose weight using safe and effective supplements. My own personal journey to better health has been an inspiring one, and I am passionate about helping others achieve their goals as well. Whether you are looking to improve your overall wellness or simply want to shed a few pounds, I can help you reach your goals with the right supplement regimen customized specifically for you. Contact me today to get started on your healthy new future!

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