Cellucor's C4 Smart Energy Gets a New Look, Keeps the Cognizin Coming

Nutrabolt refreshed the C4 Smart Energy cans and added a few flavors, but left the good part alone. Cognizin® citicoline sits ahead of the 200mg natural caffeine on the label, which tells you what this line is built for.

Nutrabolt is refreshing its C4® Smart Energy line with new can art and a few new flavors joining the existing lineup that includes its famous Strawberry Guava. The formula itself carries over unchanged: 200mg of natural caffeine from green coffee beans, Cognizin® citicoline for cognitive support, N-Acetyl-L-Tyrosine, and a trio of B-vitamin and electrolyte nutrients, all in a zero-sugar, zero-calorie 12 fl oz can.

Ignite Your Brilliance: C4 Smart Energy is Back

The line's "Ignite Your Brilliance™" positioning sets it apart from Cellucor's harder-hitting C4 Energy and C4 powdered pre-workout lines. Instead of leading with a big stimulant hit, Smart Energy leads with Cognizin, a branded citicoline form from Kyowa Hakko that's become a go-to cognitive-support ingredient across the energy drink and nootropic beverage space. C4 pairs it with natural caffeine and N-Acetyl-L-Tyrosine for a formula built around focus and mental output rather than pure stimulation.

The refresh comes not long after Nutrabolt CEO Doss Cunningham sat down with us to talk through C4's origin story and Cellucor's own brand rebrand, a conversation worth revisiting for anyone curious about where the C4 family of products is headed next. It also follows Cellucor's broader push into a sharper wellness identity, so this can redesign for Smart Energy fits a brand that's been actively updating its look across the board in 2026.

Let's dive into the label below, but first, check flavor availability with PricePlow:

C4 Smart Energy Nutrition Facts

Per 12 fl oz can, each with 200mg natural caffeine:

• Calories - 0

• Total Fat - 0g

• Total Carbohydrate - 0g

  • Total Sugars - 0g

    • Added Sugar - 0g

• Protein - 0g

• Vitamins and Minerals

  • Potassium - 190mg (4% DV)

  • Niacin - 30mg (190% DV)

  • Vitamin B12 - 6mcg (250% DV)

  • Sodium - 0mg (0% DV)

C4 Smart Energy® Ingredients

Each 12 fl oz can provides the following:

• Cognizin® Citicoline

  Cognizin® is a branded, standardized form of citicoline (also called CDP-choline) made by Kyowa Hakko, and it's the ingredient doing most of the work behind Smart Energy's "Ignite Your Brilliance" positioning. Once ingested, citicoline breaks down into choline and cytidine, which cross the blood-brain barrier and get rebuilt into the compound that feeds production of phosphatidylcholine, a structural building block of neuronal cell membranes. Citicoline is also linked to increased dopamine and norepinephrine activity in the brain, thought to happen through activation of tyrosine hydroxylase and reduced dopamine reuptake at the synapse,^[1] so it'll work well next to the N-Acetyl L-Tyrosine discussed below.

  The strongest human evidence sits with attention and memory. In healthy women aged 40 to 60, 250mg or 500mg per day of citicoline for 28 days significantly reduced errors on a sustained-attention test compared to placebo, with the lower dose also improving accuracy.^[2] In a 12-week trial in older adults with age-associated memory impairment, 500mg per day of Cognizin citicoline produced significantly greater improvements in episodic memory and composite memory scores than placebo.^[3] A 2005 Cochrane review pooling 14 placebo-controlled trials, mostly in older adults with cognitive or cerebrovascular impairment, found small but statistically significant benefits for memory and behavior, though it found no effect on attention specifically in that older, impaired population.^[4] More recently, a two-week trial in healthy young adults found that 500mg per day improved reaction time and working memory accuracy on N-back tasks relative to placebo.^[5]

  

  Across this research, effective doses range from roughly 250mg to 2,000mg per day, with 500mg being the most common dose in modern trials. C4 Smart Energy's label doesn't disclose how much Cognizin citicoline the can actually contains, so there's no way to confirm whether it falls within that studied range. But given the brand's positioning and the fact that it's ahead of caffeine, we're thinking it's at 250mg and will confirm if we can find out.

  Citicoline carries an excellent long-term safety record at these doses, with no serious adverse events reported across the trials above.

• Natural Caffeine (from Green Coffee Bean Extract) - 200mg

  Natural Caffeine works primarily by blocking adenosine receptors in the brain and body. Adenosine is an inhibitory compound that builds up during wakefulness and promotes fatigue, so blocking its receptors increases the availability of stimulating neurotransmitters including dopamine and norepinephrine.^[6]

  At 200mg, C4 Smart Energy's dose sits right in the range shown to reliably improve reaction time, sustained attention, and vigilance in both rested and fatigued adults, with doses of 32mg to 300mg producing consistent benefits in the research.^[6] On the metabolism side, a 2023 meta-analysis of 94 studies found caffeine produces a small but statistically significant increase in fat metabolism, an effect that didn't really scale with dose above roughly 3mg per kilogram of body weight.^[7] This lines up with C4's own on-can qualifier that the fat-loss claim applies alongside a calorie-reduced diet and an active lifestyle, not as a standalone effect.

  The FDA classifies caffeine as Generally Recognized As Safe at intakes up to 400mg per day for healthy adults, twice what's in a single can here.^[8] A separate systematic review of 381 studies reached a similar conclusion, finding that up to 400mg per day in healthy adults isn't associated with cardiovascular, behavioral, or other adverse effects.^[9]

  

  Long story short? A can will feel good. Two cans throughout the day is the max, and will probably get you into the higher-end Cognizin studies too.

• N-Acetyl-L-Tyrosine

  N-Acetyl-L-Tyrosine is a soluble form of L-tyrosine, the amino acid the body uses to build the catecholamine neurotransmitters dopamine and norepinephrine. Under normal, unstressed conditions, the enzyme that converts tyrosine into these neurotransmitters is already close to saturated, so simply adding more tyrosine doesn't do much. During physical or psychological stress, though, catecholamine-producing neurons fire more and deplete their local tyrosine pools faster, which is when extra tyrosine appears to matter most.^[10]

  A review of the tyrosine literature concluded it reliably improves cognitive performance, especially working memory and cognitive flexibility, when people are under acute stress or demanding cognitive load, but shows little benefit at rest.^[10] In a military combat training study, cadets given a substantial 2 grams of tyrosine per day for five days performed significantly better on memory and tracking tasks than those given a placebo drink.^[11] We won't have that here, but it's good to know for those who are investigating the ingredient.

  The doses used in this research range from roughly 2 grams up to 150mg per kilogram of body weight (over 10 grams for a 70kg adult), far above what a beverage can typically deliver. C4 Smart Energy's label doesn't disclose an amount, so this section should be read as background on the ingredient rather than a claim that the can matches these clinical doses.

• Niacin (as Niacinamide) - 30mg (190% DV)

  

  Niacin, listed on the label as niacinamide, is vitamin B3. It's the metabolic precursor to NAD+ and NADP+, coenzymes involved in hundreds of reactions that convert food into usable energy, including glycolysis and the TCA cycle. At 30mg (190% of the Daily Value), C4 Smart Energy's niacin dose is a standard nutritional-support amount, well within an established B-vitamin panel rather than the gram-level doses used in cardiovascular research that doesn't apply as much at this level.

• Vitamin B12 (as Cyanocobalamin) - 6mcg (250% DV)

  Vitamin B12, sourced here as cyanocobalamin, is a cofactor in red blood cell formation and the methionine cycle, which supports normal energy-yielding metabolism. At 6mcg (250% DV), the dose comfortably covers the adult RDA of 2.4mcg. Most B12 research showing measurable effects on energy or fatigue uses far larger doses, generally 500mcg to 1mg or more, and a meta-analysis of 16 RCTs at those higher doses found no consistent benefit for cognitive function or fatigue in people who weren't deficient.^[12] At the level in this can, B12 is standard nutritional fortification, not a performance dose.

• Potassium (as Potassium Citrate) - 190mg (4% DV)

  Potassium is the body's primary intracellular electrolyte, and most American diets fall well short of the 4,700mg daily target.^[13] At 190mg, C4 Smart Energy contributes a modest amount toward that daily gap, and we'll take it anywhere because everyone's so short of the number these days.

  The blood pressure and metabolic research on potassium generally uses supplemental doses in the range of 1,500mg to 2,500mg or more, so the amount here is best understood as a minor nutritional contribution alongside the can's other electrolyte and B-vitamin content, not a clinically significant electrolyte dose on its own. But what has been found from the research is that it's not about dropping sodium so much as increasing potassium. Since this gets you nearly 200mg more and no sodium, that's a huge win. Sodium's of course easy to get in your food.

Flavors Available

Here's an up-to-date list of all flavors of C4 Smart Energy:

Who It's For

• Focus-first energy drinkers: People who want an energy drink built around mental output rather than a big stimulant hit will find Smart Energy's Cognizin-led formula a different approach than C4's harder-hitting pre-workout-style energy lines.
• Sugar-conscious consumers: With zero sugar, zero calories, and no artificial colors or flavors on the label, it fits shoppers looking for a cleaner can without giving up flavor variety.
• Desk workers, students, and gamers: The combination of natural caffeine, Cognizin, and N-Acetyl-L-Tyrosine targets the kind of sustained attention and mental multitasking these use cases call for.
• Flavor fiends: Let's be honest -- these flavors are insanely underrated. Strawberry Guava is on another level.

Conclusion: A Familiar Formula, A New Can

Nutrabolt CEO Doss Cunningham joins the PricePlow Podcast to talk Cellucor's rebrand, C4 Energy growth, the Bloom investment, and building the Proctor & Gamble of supplements and welness in Episode #222.

C4 Smart Energy's relaunch is about presentation more than formula. The can gets a fresh look and some new online-only flavor exclusives, but the ingredients driving the "Ignite Your Brilliance" positioning carry over: 200mg of natural caffeine, Cognizin citicoline, N-Acetyl-L-Tyrosine, and a supporting cast of B-vitamins and electrolytes, all in a zero-sugar can.

What differentiates Smart Energy within Cellucor's broader C4 lineup is the cognitive framing. Where C4 Energy has leaned into big flavor collaborations and C4 Sport powder targets NSF-certified athletic performance, Smart Energy is positioned for people who want to feel sharp, not just wired. The caveat worth keeping in mind is that Cognizin and N-Acetyl-L-Tyrosine amounts aren't disclosed on the label, so shoppers who want to compare doses against the clinical research will need to dig deeper. With that said, we believe this is the 250mg Cognizin dose and will confirm if we can.

Check PricePlow for current pricing and availability on C4 Smart Energy, and sign up for Cellucor and C4 price alerts to get notified as new flavors hit the shelves.