C4 Smart Energy Review – Is This Ready-To-Drink Beverage Legit?

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By Thomas Youngerman

Reviewed by Juliana Tamayo, MS, RDN - Last Updated

C4 Smart Energy Review

Walk into the refrigerated drink section at any convenience or grocery store today, and you may think you’re in a sports nutrition store. Gone are the days of energy drinks being for energy only. Now, the category is saturated with drinks featuring cognitive benefits, electrolytes, pre-, post-, and intra-workout components, meal replacements, and weight management aids. The Ready-to-Drink (RTD) category has exploded to more than $90 billion globally, and everyone, manufacturers and retailers alike, wants their piece of the action. To illustrate, I purchased the samples for this C4 Energy review in a very upscale food retailer, and the product was available in the refrigerated section, a grocery aisle, and a massive endcap display. There is no way this would have occurred just a few short years ago. 

This article will review one of the C4 RTD offerings, C4 Smart Energy. Cellucor’s C4 franchise includes powders, some forty-nine different formulas and flavors, and Carbonated and Non-Carbonated ready-to-drink beverages, thirty-eight varieties. Why select Smart Energy? Although not everyone is an athlete seeking performance components to increase strength and endurance, most people buy an energy drink for energy and probably a bit of clarity and focus. We’ll tell you how C4 performs versus its claims, review its ingredients and their function, discuss price/value, and provide our ratings. Along the way, we’ll briefly introduce you to the parent company and give just a few recommendations as to other RTDs you may wish to consider. 

C4 Smart Energy Carbonated Ready-to-Drink Beverage

Cellucor’s C4 was a pioneer in the powdered pre-workout category and today is the number one selling brand globally. The parent company, Nutrabolt, is the largest privately held business in the sports nutrition category. From its early roots with a minimal number of flavors in one size, the C4 franchise has expanded to some eighty-seven different offerings today.

Other Cellucor Reviews:

Expansion into the Ready-to-Drink segment was a logical strategy for the brand, and the Cellucor team is a savvy group. 

C4 Smart Energy is a carbonated beverage delivered in twelve-ounce cans sold everywhere, online and in stores. The product promises natural energy, enhanced mental focus, and supports fat loss, while promoting a feeling of well-being.

c4 smart energy

The Nutritional Facts Panel doesn’t tell us much, as the product has no calories, fat, sodium, carbohydrates, sugars, or protein. Nutrients include Potassium, Niacin, and Vitamin B12. Key ingredients in the formula are Caffeine, Cognizin, a patented compound, and N-Acetyl Tyrosine, an amino acid.

C4 Smart Energy contains no sugar, artificial flavors, or colorings, and the caffeine is from natural sources; however, it does contain Sucralose, an artificial sweetener and sugar substitute.  

All Cellucor products are manufactured in FDA-registered, GMP-compliant facilities. C4 Energy products are third-party tested, and NSF certified as Safe for Sport, free of banned substances. 

C4 RTDs come in carbonated and non-carbonated varieties


  • C4 Smart Energy – 8 flavors, plus Variety Packs
    • Peach Mango, Cherry Berry Lime, Blood Orange Yuzu, Watermelon Burst, Tropical Passionfruit, Strawberry Guava, Blue Raspberry, and Black Cherry
  • C4 Performance Energy – 7 flavors, plus Starburst with four flavors and one Skittle variety
  • C4 Ultimate Energy, Superbrain – 6 flavors


  • C4 Energy – 4 flavors
  • C4 Ultimate – 4 flavors

Cellucor/Nutrabolt has come a long way since its early days of sponsoring local bodybuilders and competitions. Today, C4 athletes include NFL rising stars Justin Fields and Kyle Pitts, the NBA’s Lonzo Ball, WWE wrestlers, formula driver Lindsey Brewer, and entertainer Kevin Hart, among others. Impressive!

A twelve-pack of C4 Smart Energy sells on the company website at $22.49, or $1.88 per 12-ounce can, plus shipping. Shipping is free with a subscription at the same $22.49. Variety Packs of twelve sell for the same price. Other retailers sell the product as follows:

  • Amazon – $22.49 / $1.88 can
  • GNC – $29.99 / $2.50 can
  • Vitamin Shoppe – $32.99 / $2.75
  • Walmart – $25.99 / $2.16
  • Target – $2.29 per can ($27.48 per 12-pack)
  • Safeway – $2.50 per can ($30.00 per 12-pack)
  • AJ’s Fine Foods – $2.99 can ($36.00 12-pack)

C4 Smart Energy Key Ingredients

c4 smart energy ingredients

200 mg of Caffeine

Caffeine from natural sources, green coffee beans. About two cups of coffee – less than a Starbucks Americano Espresso.

  • The Journal of American Medicine cites the benefits of caffeine as increased energy and alertness, improved reaction time, delayed fatigue, and reduced appetite. 
  • The NCBI (National Center for Biotechnical Information) further states that caffeine may improve time to exhaustion by 12% in cardio exercise.  
  • The Harvard T.H. Chan School of Public Health reports that low to moderate doses of caffeine (50–300 mg) will benefit energy, alertness, and the ability to concentrate, while consuming larger amounts of caffeine from natural sources is associated with lower death rates from all causes.


A patented, trademarked, and clinically validated form of citicoline to support mental focus, attention, and recall. Although the brain represents only 2% of a human body’s weight, it consumes up to 20% of its energy when at rest, and citicoline is nature’s way of keeping the brain’s energy-producing centers firing. Numerous clinical studies validate Cognizin’s benefits in memory and recall, motor speed, and attention. They may help modulate appetite for weight management.

N-Acetyl Tyrosine

A form of the amino acid L-tyrosine that helps to support mental health during stressful activities. L-tyrosine is a precursor for dopamine and norepinephrine, which, when depleted under stress, may compromise cognitive function. L-tyrosine helps alleviate stress-induced cognitive decline by restoring their levels in the brain.

B Vitamins

Smart Energy contains more than 100% of the Daily Recommended Value of important B vitamins, B12 and Niacin (B3). 

What to Expect from C4 Smart Energy

First, let’s start with taste because if it doesn’t taste great, why bother?


With eight flavors, there is something that will suit everyone. I have tried several, and although all are good, the Strawberry Guava and Peach Mango are delicious. The Tropical Oasis Variety Pack would be a great option for those seeking a good place to start. It includes the two flavors mentioned, the Blood Orange Yuzu, excellent, and Tropical Passionfruit.

c4 smart energy

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C4 Smart Energy

  • Ingredients include caffeine, cognizin, n-acetyl tyrosine, and B vitamins
  • Formula features natural caffeine from green coffee beans
  • Benefits energy, performance, and more

How Much Energy Can You Expect from C4 Smart Energy?

We think you’ll be pleasantly surprised by the gentle boost of clean energy from C4 Smart Energy. I drink three to four cups of black coffee every morning, and my go-to pre-workout supplement has 300 mg of caffeine anhydrous, so my tolerance for caffeine is substantial. I’ve used C4 Smart Energy before a cardio workout and resistance training and noticed a nice energy boost from its 200 mg of natural caffeine in both instances. 

C4’s natural caffeine from green coffee beans is a nervous system stimulant that increases energy and delays fatigue. Further, caffeine may aid in weight and body fat reduction, enhance athletic performance, and many other potential health benefits. Caffeine is also associated with heart health and longevity – smart. 

With Smart Energy, there were no noticeable jitters as with some stimulants in supplements. There was no crash once the energy wore down. 

c4 smart energy in hand

C4 Smart Energy Benefits

C4 Smart Energy is positioned to address morning grogginess and midday slumps, elevate mental focus for multitasking or gaming, and aid in fat loss – when used in conjunction with a calorie restriction diet and an active lifestyle. As indicated, I noticed a nice energy bump and a sense of clarity when taking C4 Smart Energy, sufficient to re-energize me and help my writing. However, I used this C4 variety pre-workout, both cardio and resistance training.

Typically, for cardio, I skip the pre-supplement and use electrolytes and water for hydration and to fuel my rides. The C4 provided a bit of extra energy and motivation to start my ride, and I completed my normal session, ten miles in 95° plus with lots of hills. I can’t say that fatigue was delayed by 12% (as reported by the NCBI), but I completed the ride feeling good.

C4’s impact on resistance training was a revelation. First, the energy from the natural caffeine was on par with my powdered pre-workout supplement, as previously noted, with 300 mg of caffeine anhydrous. I also was as focused and possibly more motivated as I began my session, surprising as my typical pre-workout contains Huperzine A and Alpha GPC, two nootropic compounds. As the training session progressed, I noticed less vascularity and muscle pumps versus my normal, due no doubt to the lack of nitric oxide components such as arginine, citrulline, or beetroot. Finally, completing the session was challenging, as my muscles fatigued without a creatine, beta-alanine, or BCAA compound.

The product delivers as promised and perhaps exceeds expectations to some degree. Although great for my pre-cardio, it was apparent that the ergogenic compounds found in other pre-workout supplements are essential for resistance training.  

C4 powders and the C4 Performance Energy drink contain more ingredients required for an effective pre-workout, such as Beta-alanine, Citrulline, and Betaine in the C4 Performance Energy RTD, plus Creatine in the powder.

Other popular brands of RTD drinks include: 

  • Mr. Hyde or Bucked Up – for hard-core intensity training
  • Reign Body Fuel or Amin.O Energy – for energy with BCAA support
  • Xyience and Bang – for energy and focus, Bang also has EAAs (Essential Amino Acids)

In Summary: C4 Smart Energy Review

Cellucor/Nutrabolt is a respected player in the sports nutrition space and adheres to best practices in manufacturing, testing, and third-party certifications. Although I paid a premium for the product given where it was purchased, it is competitive in the category at $1.88 – $2.50 per can online and in other stores. The taste of the Strawberry Guava was excellent. I will purchase it again as a great pick-me-up and to help me refocus on groggy afternoons or use pre-cardio for a little extra energy. Hopefully, on future rides, the delayed fatigue benefit of caffeine will come into play. 

Overall Rating:
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Thomas Youngerman

Thomas Youngerman is an entrepreneur and author in the health and wellness space with extensive experience in the supplement industry. He has owned multiple sports nutrition stores and served as the Category Manager and Director of Business Development for a regional chain of nutrition stores. Thomas created a successful line of men’s healthy aging supplements that was distributed in GNC, The Vitamin Shoppe, and Kroger, and later sold to a West Coast corporation. Thomas was previously a certified nutrition coach. He has a strong understanding of nutrition, supplement formulations, DSHEA, cGMP, and FDA regulations.