For a first food shop, start with a clearly labelled sugar-free or zero-sugar drink, then check the sugars figure and caffeine per whole can. Red Bull lists 80 mg of caffeine in its 250 ml Sugarfree can, while Monster lists 150 mg in 500 ml Ultra and 160 mg in 500 ml Energy Zero Sugar; consider your other caffeine sources and whether the pack size suits you before choosing.
If you do not want to pick up a sugary variety by mistake, compare the claim on the can with its sugars figure and ingredient list. Check caffeine separately: a sugar-free claim says nothing about whether the drink contains it.
Red Bull states that its 250 ml Sugarfree can contains 80 mg of caffeine. That is a smaller stated amount per can than Monster lists for its 500 ml Ultra and Energy Zero Sugar varieties, at 150 mg and 160 mg respectively.
Monster describes Ultra and Energy Zero Sugar as zero-sugar options, but lists different caffeine amounts for their 500 ml cans. Check the particular variety and account for caffeine from other drinks rather than treating zero sugar as a caffeine choice.
For a first food shop, establish which sugar claim you need, check caffeine for the entire can, then choose a flavour and pack size you are prepared to buy.
| Priority | What to check | Your needs |
|---|---|---|
| Sugar claim | Read the exact claim, the sugars figure per 100 ml and the ingredients. The Advertising Standards Authority distinguishes a no-added-sugars claim from a claim that a drink contains no sugar. | I want to avoid added sugars, so I need to check more than the flavour name or the presence of a sweetener. |
| Caffeine per can | Compare the whole-can amount, not just the can size or a per-100 ml figure. Red Bull lists 80 mg per 250 ml Sugarfree can; Monster lists 150 mg per 500 ml Ultra can and 160 mg per 500 ml Energy Zero Sugar can. | A smaller caffeine serving matters to me, especially if I also drink coffee, tea or cola. |
| Variety and sweeteners | Check the named variety and its ingredients. Monster describes Ultra as lighter tasting and its Energy Zero Sugar variety as original-style; a sweetener in the ingredients does not establish that no sugar was added. | I would rather choose the flavour I intend to drink than assume every zero-sugar variety tastes alike. |
| Pack size | Check the number of cans as well as the volume of each one. A multipack contains several servings, even when each can is comparatively small. | For my first shop, I may want fewer cans while I decide whether the flavour and caffeine serving suit me. |
Zero-sugar cans can still contain substantial amounts of caffeine. Red Bull states 80 mg per 250 ml Sugarfree can, while Monster states 150 mg per 500 ml Ultra can and 160 mg per 500 ml Energy Zero Sugar can.
Read the amount for the entire container and consider caffeine from other drinks or supplements before choosing a multipack.
A drink can contain both. Relentless lists sucrose and glucose in Cherry, and sucrose in Guava, alongside sweeteners in the researched varieties.
If avoiding added sugar is your requirement, check the ingredient list and sugars figure on the exact drink.
The Department of Health and Social Care describes an under-16 restriction for high-caffeine energy drinks in England, and Newcastle City Council gives April 2027 as its start date. That does not establish the same rule for every UK nation or every retailer.
Check the retailer's current age-verification requirements and the rules where the purchase takes place.
Red Bull Sugarfree is a 250 ml sugar-free energy-drink option.
Monster's Ultra and Energy Zero Sugar varieties offer distinct zero-sugar options in 500 ml cans.
Lucozade describes its Zero range as zero-sugar soft drinks in several flavours.
Relentless varieties need checking individually against a no-added-sugar requirement.
Tesco's energy-drinks category provides a grocery-shopping reference for sugar-free and zero-sugar varieties.
These options are zero-sugar energy drinks in 250 ml or 500 ml cans, sold as multipacks. Compare caffeine per can and the number of cans when deciding what fits a first shop.
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An original-style Monster option if you want zero sugar and are choosing a 500 ml can. Monster lists 160 mg caffeine per 500 ml Energy Zero Sugar can; consider other caffeine sources. This pack contains four cans.
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Monster describes Ultra as a lighter-tasting zero-sugar variety. It lists 150 mg caffeine per 500 ml can, so check whether that serving suits you alongside other caffeine sources. The case contains 24 cans.
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A smaller can for shoppers comparing caffeine per complete serving: Red Bull states 80 mg per 250 ml can. Sugarfree contains sweeteners, and this is a 12-can pack rather than a single-can trial. The product warning advises against use by children, pregnant or breastfeeding women, and people sensitive to caffeine.
No. The Advertising Standards Authority explains that a no-added-sugars claim concerns added sugars and foods used for sweetening; it does not mean the finished drink contains no sugar. Read the exact claim, the sugars figure and the ingredient list on the can.
No. Monster lists 150 mg caffeine per 500 ml Ultra can and 160 mg per 500 ml Energy Zero Sugar can; Red Bull lists 80 mg per 250 ml Sugarfree can. Check the amount for the whole can separately from its sugar claim.
Yes. The European Food Safety Authority's 2015 assessment discusses caffeine intake from all sources, not energy drinks alone. For healthy non-pregnant adults, it reports no safety concern at single doses up to 200 mg or habitual intake up to 400 mg per day; these figures are not a target to consume. Include coffee, tea, cola and supplements when considering your total.
Choose a multipack if you are comfortable with both the flavour and caffeine amount per can, and the number of cans suits your plans. If you have not tried a variety, check the pack count before committing to a case.