For an adult choosing a sparkling energy drink during revision, compare caffeine in the whole can before deciding on size or sugar content: Red Bull UK lists 80mg in its 250ml Original and Zero cans, while Monster Energy UK lists 150mg for a 500ml Ultra can and 160mg for a 500ml Original Green can. Zero sugar does not mean less caffeine, and the figures for those named drinks should not be assumed to apply to other flavours. If refreshment is the main aim, an energy drink is not necessary; for children, choose a drink without a high-caffeine warning instead.
If you plan to drink the whole can while revising, its total caffeine matters more than the brand name or a per-100ml figure viewed on its own. Include tea, coffee and other caffeine-containing drinks when considering what else you will have that day.
A zero-sugar version can meet a preference for a drink without sugar, but it still needs a separate caffeine check. The can size and the exact variant both matter.
Check age-related warnings before treating an energy drink as an exam snack. Relentless says its White Citrus drink is not recommended for children; Sainsbury's says it does not sell high-caffeine energy drinks to under-16s. The Department of Health and Social Care has announced an under-16 sales restriction for high-caffeine energy drinks in England from April 2027, not a current UK-wide rule.
Start with the drink you would actually finish, then compare its caffeine, sugar formulation and warnings against what you want from a revision break.
| Priority | What to check | Your needs |
|---|---|---|
| Caffeine per can | Check the caffeine total for the exact can size and variant. Red Bull UK lists 80mg per 250ml can for Original and Zero; Monster Energy UK lists 150mg per 500ml Ultra can and 160mg per 500ml Original Green can. Account for other caffeine-containing drinks too. | I want to know how much caffeine is in the can I might finish, rather than compare brands by name alone. |
| Sugar formulation | Compare sugars for the serving you intend to drink, alongside caffeine. Red Bull UK lists the same 80mg caffeine per 250ml can for Original and Zero; Monster Energy UK describes its 500ml Ultra as zero sugar with 150mg caffeine. | If I choose zero sugar to avoid sugar in the drink, I still need to check its caffeine separately. |
| Age and warnings | Read the warning on the exact pack and check the retailer's age policy. The UK Department of Health and Social Care describes a high-caffeine labelling requirement for qualifying drinks; England's announced under-16 sales restriction is scheduled for April 2027. | When buying for a younger reviser, I would choose a drink without a high-caffeine warning rather than assume revision changes the age guidance. |
| Sparkling format | Confirm that the specific drink is sparkling or carbonated, then check its own ingredients and label. Lucozade describes its Energy range as sparkling and containing glucose; that description alone does not establish the caffeine amount of an individual variant. | I may want a fizzy drink for a break without choosing solely on the basis of an energy-drink name. |
The two describe different things. Red Bull UK lists 80mg caffeine per 250ml can for both Original and Zero, while Monster Energy UK lists 150mg per 500ml can for its zero-sugar Ultra.
Use the sugar information to compare sugar, then check caffeine in the full can separately.
For the named variants, Monster Energy UK lists 150mg or 160mg caffeine in a 500ml can, while Red Bull UK lists 80mg in a 250ml can. A per-100ml comparison alone can obscure what finishing each can means.
Compare whole-can amounts for the exact products you are considering, particularly if you will also have tea or coffee.
Relentless says its White Citrus drink is not recommended for children, people sensitive to caffeine, or pregnant or nursing women. Sainsbury's has its own under-16 sales policy for high-caffeine energy drinks.
For a child or younger teenager, choose a drink without a high-caffeine warning and check the retailer's policy before ordering.
A range may contain different formulations and can sizes. Lucozade describes its Energy range as sparkling and containing glucose, but that range description does not give a caffeine amount for every variant.
Check the exact pack for caffeine, sugars, ingredients and warnings before choosing it.
These references describe particular drinks or ranges, not every product made by each brand.
Red Bull UK lists 250ml Original and Zero cans, allowing a comparison at the same can size.
Monster Energy UK lists 500ml Original Green and zero-sugar Ultra cans with different stated caffeine totals.
Lucozade describes its Energy range as sparkling and containing glucose.
Relentless describes White Citrus as a carbonated citrus-flavour energy drink.
These options cover smaller Red Bull cans and larger Rockstar and Monster cans for adults comparing a sparkling drink during revision. Check each exact pack rather than applying one variant's caffeine figure to another.
No image available
For an adult comparing smaller cans during revision, this pack contains twelve 250ml cans. Red Bull UK lists 80mg caffeine per 250ml can for Red Bull Energy Drink; check the pack's sugar information alongside that amount.
No image available
For an adult choosing a zero-sugar version in a smaller can, this pack contains four 250ml cans. Red Bull UK lists 80mg caffeine per can for Red Bull Zero, so the zero-sugar choice still calls for a caffeine check.
No image available
If you are considering a larger sparkling can for a revision break, this pack contains twelve 500ml cans. Check caffeine and sugars for this exact flavour and whole can before comparing it with a smaller option.
No image available
This four-pack is an option for adults considering a larger lemonade-flavour energy drink. Check caffeine and sugars on the Aussie Style Lemonade pack itself; figures for Monster Original Green or Ultra should not be applied to this variant.
No image available
For an adult considering a larger zero-sugar can, this pack contains four 500ml cans. Check the exact pack label for caffeine per can before choosing it; zero sugar does not establish the caffeine amount.
Compare the amount in the whole can you intend to drink, then consider tea, coffee or other caffeine sources that day. Red Bull UK lists 80mg per 250ml can for Original and Zero; Monster Energy UK lists 150mg per 500ml Ultra can and 160mg per 500ml Original Green can. Check the exact variant rather than transferring those figures to another flavour.
No. Red Bull UK lists 80mg caffeine per 250ml can for both Red Bull Zero and Red Bull Energy Drink. Monster Energy UK lists 150mg per 500ml can for its zero-sugar Ultra, so compare sugar and caffeine as separate label details.
The answer depends on where and from whom they are buying; there is no single current UK-wide rule stated here. The Department of Health and Social Care has announced an under-16 sales restriction for high-caffeine energy drinks in England from April 2027. Separately, Sainsbury's says it already does not sell high-caffeine energy drinks to under-16s under its retailer policy.
It flags a drink covered by a caffeine labelling requirement, not a recommendation to use it for studying. The UK Department of Health and Social Care states that drinks other than tea or coffee containing more than 150mg caffeine per litre require a warning label. Read that warning and the caffeine declaration on the exact pack, especially when buying for a younger reviser.