C4
C4 Smart Energy Drink
The delicious sugar-free energy drink, C4® Smart Energy, is powered by InnovaTea® Naturally Derived Caffeine (from Green Tea) and brain-boosting Cognizin® Citicoline to deliver energy, focus, and mental performance to help you conquer any task—from work to play, gaming to studying, partying to planning.
Our verdict: Ranked #74 of our top 109 ready-to-drink coffee — a strong medium pick with cherry notes, earning a 4.4★ average across 616 Amazon ratings.
BrewRank is reader-supported. When you buy through links on our site we may earn an affiliate commission — it never affects a score.
Key facts
- Roast
- Medium
- Origin
- Multi-region blend
- Process
- Roasted
- Size
- 12 oz
- Price / oz
- $1.87
- Best for
- Drip
Flavor notes
The Coffee Score review
The delicious sugar-free energy drink, C4® Smart Energy, is powered by InnovaTea® Naturally Derived Caffeine (from Green Tea) and brain-boosting Cognizin® Citicoline to deliver energy, focus, and mental performance to help you conquer any task—from work to play, gaming to studying, partying to planning. Our team spent hands-on time with the C4 Smart Energy Drink to see how it holds up against the rest of the ready-to-drink coffee we've tested.
Across repeated sessions we evaluated it on the categories that matter most: quality, consistency, value, and how likely we are to reach for it again. Ranked #74 of our top 109 ready-to-drink coffee — a strong medium pick with cherry notes, earning a 4.4★ average across 616 Amazon ratings.
From the roaster
- ENERGY TO OVERACHIEVE - Formulated with 200mg of InnovaTea Naturally Derived Caffeine produced from tea leaves that delivers anytime energy and alertness. Conquer any task from work to play, gaming to studying, partying to planning to pre workout
- SUGAR-FREE BEVERAGE FOR MEN & WOMEN - Zero sugar, zero calories, and zero carbs in every delicious serving, with no artificial colors or dyes
- DELICIOUS FLAVORS UNLIKE ANYTHING ON THE MARKET - Icy Blue Razz, Black Cherry, Cotton Candy, Electric Sour, Freedom Ice, and Peach Mango Nectar
- PACKAGING MAY VARY* - New Look, Same C4 Smart Energy!
What we liked
- Strong overall Coffee Score of 8.2/10 — ranked #953 of 1193 (80% percentile).
- Distinct flavor profile: Cherry.
- Community agrees — a Coffee Lovers Score of 8.8/10 from 616 ratings.
How we graded this coffee
Grading frameworkThe Coffee Lovers Score
Averages 4.4★ from 616 verified Amazon shoppers.
-
Michelle Candler Verified purchase ★★★★★
Crisp Energy and Amazing Watermelon Flavor
This C4 Smart Energy in watermelon is exactly what I want in a clean energy drink. The flavor is bright, refreshing, and not overly sweet, and the sugar‑free formula keeps it light. The energy boost is smooth and focused — no jitters, no crash, just steady alertness that lasts.
-
Pam Wood Verified purchase ★★★★★
Energy drink that works!
One of the best tasting energy drinks I've had! Gives me energy without the gutters or the crash like some others I've tried. Will order again!
-
AvidShopper333 Verified purchase ★★★★★
Effective and Light Taste!
This is more of a fresh watermelon flavor than a candy. Watermelon flavor is so many other energy drinks are. The ingredients are straightforward. I do feel like I was more focused and it is fairly good value for the money. No sugar or respectable amount of caffeine and it was very effective.
-
J. Diaz Verified purchase ★★★★☆
Cucumber flavor, not watermelon as advertised
Not a bad flavor just not watermelon flavor. It tastes almost exactly like a cucumber energy drink instead. Rebrand it to cucumber summer slam or something. Tastes nothing like watermelon though.