Quick answer: for studying, pick a drink with a moderate caffeine dose (75 to 150mg) and under 5g of sugar, and sip it at the start of a study block rather than late at night. Caffeine contributes to increased alertness and improved concentration, but sleep is what turns revision into memory. Energy drinks are for over-16s only.
Study drinks compared
| Drink | Caffeine | Sugar | For a study session |
|---|---|---|---|
| Mug of coffee | About 100 to 140mg | None, unless added | Cheap, quick, hot |
| Tea | About 75mg a mug | None, unless added | A lighter lift, easy to repeat |
| Red Bull (250ml) | 80mg | 27.5g | Quick hit, sugar slump later |
| Monster Energy (500ml) | 160mg | 55g | Nearly two days' free sugars |
| PÜRCHARGE (330ml) | 125mg | 3.8g | Still, sipped through a study block |
Figures from UK retailer listings, October 2026. Recipes change, so check the can.
How to drink for a study day
- Start of your hardest block: one caffeine drink, sipped over the first hour.
- Every hour: a short break and a glass of water.
- Cut-off: no caffeine in the six hours before bed.
- Limit: keep total caffeine under 400mg a day, coffee included.
What about all-nighters?
Caffeine can keep you awake, but sleep is when your brain stores what you revised. An all-nighter before an exam usually costs more than it gains. If you're behind, a few focused hours and a full night's sleep beat cramming until 4am.
Where PÜRCHARGE fits
For university students and adults studying, not school pupils. Each still 330ml can has 125mg of caffeine from green coffee, 3.8g of sugar, stevia, green tea extract (a natural source of L-theanine), enXtra®, rhodiola, Panax ginseng, electrolytes and nine vitamins. Vitamins B6 and B12 contribute to the reduction of tiredness and fatigue. Not for under-16s, pregnant or breastfeeding women. Max two cans a day.
See our focus drink page, or read energy drinks without jitters.
FAQs
What is the best energy drink for studying?
One with a moderate caffeine dose and little sugar, sipped at the start of a study session. Coffee and tea work too.
What is the best energy drink for students in the UK?
For over-16s, a low-sugar drink with a clearly stated caffeine dose. Under-16s shouldn't have high-caffeine drinks at all.
Should I drink an energy drink before an exam?
Only if you're used to caffeine. Try it on a revision day first, have it an hour before, and don't drink more than usual: nerves plus extra caffeine can make you shaky.
