First-time grocery shoppers
If you are choosing an occasional fizzy energy drink, compare the can volume, caffeine and sugars for the whole can. For a multipack, check how many cans you intend to keep.
Who needs which checks?
The most useful label details depend on whether you are choosing an occasional can, comparing sugar or checking a high-caffeine warning.
Shoppers comparing sugar
Look for the exact sugar-free or zero-sugar variant you want, then check its caffeine declaration and ingredients separately. The variant name does not establish its caffeine amount.
Shoppers checking caffeine warnings
Read the warning on the particular can if it is intended for a child, someone who is pregnant or breast-feeding, or someone sensitive to caffeine. Sugar content is not a substitute for that check.
What should you compare?
Start with the whole-can figures, then check the variant and pack quantity. Comparing only figures per 100ml can conceal the effect of a different can size.
| Priority | What to check | Your needs |
|---|---|---|
| Caffeine per can | Check the can volume and caffeine declaration. Red Bull UK lists 80mg in its original 250ml can; Monster Energy UK lists 160mg in Original Green 500ml. If a label gives mg per 100ml, calculate the amount for the full can. | I want to know the caffeine amount in the can I might drink, rather than judge it by the brand or the per-100ml figure alone. |
| Sugars and variant | Compare sugars for the full can and read the exact variant name. Monster Energy UK lists 55g sugar in Original Green 500ml; Tesco lists 19g in Relentless Origin 500ml and 19.1g in Lucozade Alert Original 500ml. Check caffeine separately on sugar-free drinks. | A sugar-free option interests me, but I also want to know its caffeine amount. If I choose a drink containing sugar, the grams in the whole can matter. |
| High-caffeine warning | Read the warning on the exact product, including who it says the drink is not recommended for. Sainsbury’s lists a 32mg/100ml high-caffeine warning for Relentless Origin; Tesco lists the same concentration in its warning for Lucozade Alert Original. | I need to check whether the warning applies to the person who would drink it, regardless of the drink’s sugar content. |
| Can and pack size | Check millilitres per can and the number of cans. Use the can volume when converting a per-100ml declaration into a whole-can amount. | For an occasional drink, I would rather choose a pack quantity I intend to use than select a multipack without checking its contents. |
Common buying mistakes
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Comparing caffeine only per 100ml
Can size changes the total: a declaration of 32mg/100ml amounts to 160mg in a 500ml can. Tesco lists that concentration for Lucozade Alert Original 500ml.
Find the whole-can amount on the label, or use the declared concentration and can volume to calculate it.
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Assuming less sugar means less caffeine
Sugars and caffeine are separate label details. Tesco lists 19.1g sugar per 500ml for Lucozade Alert Original, alongside a 32mg/100ml high-caffeine warning.
Check sugars, caffeine, sweeteners and warnings independently for the exact variant.
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Relying on a familiar name instead of the can
Variants and pack sizes can differ within a range, so a figure for one drink should not be carried over to another.
Read the ingredients, nutrition information, caffeine warning and best-before information on the can you receive.
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Overlooking who a high-caffeine warning covers
The retailer listings for Relentless Origin and Lucozade Alert Original say these drinks are not recommended for children, pregnant or breast-feeding women, or people sensitive to caffeine.
Check the exact product warning before choosing a drink for its intended recipient.
Brands and retailer references
These examples help identify the product lines and label details to compare; a retailer listing is not a substitute for the label on the can.
Red Bull
Its original energy drink provides a 250ml can for comparison with larger formats.
- Red Bull UK states that the original 250ml can contains 80mg caffeine.
- Check sugars on the exact can; a smaller serving is not, by itself, a sugar-free option.
Monster Energy
Original Green and named zero-sugar variants are distinct choices, so their labels need separate checks.
- Monster Energy UK lists 160mg caffeine and 55g sugar for an Original Green 500ml can.
- Do not apply Original Green’s figures to a different Monster variant without checking its pack.
Relentless
Origin is a 500ml sparkling energy drink listed by UK grocers.
- Tesco lists 19g sugar per 500ml for Origin; Sainsbury’s gives a high-caffeine warning of 32mg/100ml.
- The high-caffeine warning remains relevant when comparing its sugar figure with another drink.
Lucozade Alert
Alert Original is a sparkling drink sold in a 500ml can.
- Tesco lists 19.1g sugar per 500ml and a caffeine warning stating 32mg/100ml.
- The listing says Alert Original contains sugars and sweeteners; check the exact flavour’s ingredients and warning.
Tesco
Tesco is a grocery retailer, not an energy-drink manufacturer. Its category separates regular, reduced-sugar and sugar-free drinks.
- Its individual product listings provide label details for drinks such as Relentless Origin and Lucozade Alert Original.
- Use the label on the product received to confirm the current formulation and warnings.
Sainsbury’s
Sainsbury’s is a grocery retailer whose Relentless Origin listing provides a product-specific caffeine warning.
- The Origin listing states 32mg caffeine per 100ml and identifies groups for whom the drink is not recommended.
- That listing does not establish the details of other drinks or variants.
Joybuy sparkling energy drink options
These Joybuy options include 250ml, 355ml and 500ml can formats, with drinks containing sugar and variants labelled zero sugar. Check the individual can before comparing caffeine and sugars across formats.
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Monster Energy Aussie Style Lemonade 4 × 500ml
This four-can pack is a flavoured 500ml option. Compare caffeine and sugars for one whole can, and check whether four cans suit your intended use.
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Monster Energy Ultra Zero Sugar 4 × 500ml
This zero-sugar variant comes as four 500ml cans. Check its caffeine declaration and ingredients on the exact pack; zero sugar does not mean caffeine-free.
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Monster Energy Original Green Zero Sugar 4 × 500ml
The product name specifies four 500ml cans. Check the volume printed on the cans before converting any per-100ml caffeine figure into a whole-can amount.
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CELSIUS Watermelon Strawberry 12 × 355ml
The 355ml can sits between the 250ml and 500ml formats shown here. Check its whole-can caffeine and sugars, and consider whether a twelve-can pack fits an occasional purchase.
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Red Bull Energy Drink 250ml, 12-pack
For the original 250ml drink, Red Bull UK states 80mg caffeine per can. Check sugars on the exact pack before comparing it with other drinks, and consider whether twelve cans match your intended use.
Questions before you buy
Do all sparkling energy drinks contain the same amount of caffeine?
No. Red Bull UK lists 80mg in an original 250ml can, while Monster Energy UK lists 160mg in an Original Green 500ml can. Check the amount for the exact drink and full can you are considering.
Does zero sugar mean less caffeine?
No: zero-sugar wording does not establish a drink’s caffeine amount. Read the caffeine declaration and can size on the exact variant, and check its ingredients if sweeteners matter to you.
What do the warnings say about pregnancy or breast-feeding?
The retailer listings for Lucozade Alert Original and Relentless Origin say those drinks are not recommended for pregnant or breast-feeding women. For pregnancy, the NHS says caffeine from all foods and drinks counts towards its guidance of no more than 200mg a day; check the exact can and seek individual clinical advice if needed.
What matters when choosing a multipack for a first shop?
Check the number and size of cans, then read caffeine and sugars per can rather than relying on a per-100ml figure. Consider whether you intend to use the full pack, and check the best-before information on the product received.