Drink comparisons · Evidence-led guide
Monster Original vs Ultra: does sugar-free change caffeine?
The short answer
The recorded UK 500 ml servings are 160 mg for Original Green and 150 mg for Ultra White. That difference belongs to these two formulations; “sugar-free” is not a rule for caffeine content.
Inspect the documented servings
These values come from the linked catalogue records. A source-backed record is not a measurement of your drink or a guarantee of a current recipe.
| Drink / market | Serving | Caffeine | Per 100 ml | Evidence / action |
|---|---|---|---|---|
| Monster Energy Original GreenUK | 500 ml can | 160 mg | 32 mg (calculated) | Manufacturer listedVerified source record · Reviewed 2026-08-21Use this dose · Compare |
| Monster Ultra WhiteUK | 500 ml can | 150 mg | 30 mg (calculated) | Manufacturer listedVerified source record · Reviewed 2026-09-04Use this dose · Compare |
Bars use the selected measure; numbers remain visible in both units. No bar is drawn for an undocumented concentration. Per 100 ml = serving caffeine × 100 ÷ documented volume.
Compare the same market and volume
These two records use UK 500 ml cans. A smaller can can have a lower total without a weaker concentration, while another market can use a different formulation. Check both fields before comparing a number from a search result with your can.
Separate the size effect from the recipe effect
At equal volumes, the recorded difference is 10 mg. The corresponding concentrations are calculated from each record below. That is a caffeine comparison only, not a score for health, performance or suitability.
Do not generalise to the whole Ultra range
Ultra White is one product. This guide does not claim to test every Monster flavour or establish the lowest-caffeine can sold in the UK. The manufacturer pages did not expose their numerical fields during the September recheck; the prior review dates remain visible and current packaging takes precedence.
Sources and scope
- Monster Energy UK product informationUK Original Green product page. Source reviewed 2026-08-21.
- Monster Energy UK Ultra product informationOfficial UK product page; Monster notes figures are based on 500 ml and can vary by region. Source reviewed 2026-09-04.
Educational information, not medical advice. Published, calculated and approximate values have different limits. Check the current product label or recipe when an exact amount matters.