Coffee drinkers may be getting more or less caffeine than they anticipated, with levels varying "wildly" between popular high street chains, a new study by Which? has found. The consumer group analysed caffeine content in a range of drinks from Caffe Nero, Costa Coffee, Greggs, Pret A Manger and Starbucks, revealing significant differences between chains and between drinks.

Key findings

A medium cappuccino from Costa contains 325mg of caffeine, almost three-and-a-half times as much as the same drink at Starbucks, which has 89mg. The caffeine content of Costa's cappuccino is equivalent to around four cans of Red Bull. The second and third-highest cappuccino caffeine levels were found at Greggs and Caffe Nero, at 235mg and 221mg respectively.

Costa also tops the list for other drinks, with its espresso shot containing 100mg of caffeine per serving and its flat white containing 241mg. In contrast, Starbucks's espresso shot has 45mg of caffeine per serving, and its flat white has 89mg.

The study also looked at matcha drinks, which have grown in popularity in recent years. Costa's hot matcha latte contained the highest caffeine content at 99mg, followed by Starbucks at 57mg and Pret at 28mg.

Changes since 2023

While Costa's caffeine content for cappuccinos and single-shot espressos has not changed since Which?'s last study in 2023, Caffe Nero's has noticeably increased, with its cappuccino now containing around double the level of caffeine than before. Starbucks continues to serve the least caffeine overall across its drinks, but its caffeine levels have increased in its espressos, cappuccinos and filter coffees over the past three years.

Expert advice

Which? said its research showed customers should "pay attention" to the differences in caffeine levels across high street retailers, particularly for those who are advised to restrict their intake for health reasons, including pregnancy. Jessica Carson, a Which? health and wellbeing expert, noted that caffeine content varies widely from chain to chain and advised customers to be mindful of where they shop and what they order to avoid unwanted side-effects.