Finding a zero-sugar energy drink that actually delivers on flavour without that dreaded artificial chemical aftertaste can feel like a gamble. Enter C4 Energy. 

Already a powerhouse in the sports nutrition world, C4 has successfully disrupted the UK functional beverage aisle by translating high-performance pre-workout formulas into refreshing, grab-and-go cans. Packed with performance-driven ingredients like beta-alanine for endurance and a solid hit of clean caffeine, these drinks don't just fuel your workouts or midday slumps—they challenge the status quo on how good sugar-free energy can actually taste. 

Whether you are chasing the pure candy nostalgia of their official Millions sweets collaboration or looking for a sharp, zesty citrus kick, here is our definitive, taste-tested ranking of the top C4 energy drink flavours available in the UK.