A standard 250ml can of Red Bull has approximately 27g of sugar — a little over 6 teaspoons. Worth checking the can yourself, since exact figures can shift by region and formulation.
That's a meaningful amount for a single drink, and it's part of why energy drinks can leave people with a crash later — the sugar spikes blood glucose quickly, and what goes up quickly tends to come down the same way.
Sugar-free versions exist, but a lot of people don't love the taste trade-off, or still want caffeine without reaching for a can at all.
Neuchu is sugar-free and gives you a fixed 50mg of natural caffeine per piece with no drink involved. You can find it here.