Pepsi is the latest brand to launch a new "healthy" option.
Pepsi Raw is said to be made from natural ingredients and contain no artificial preservatives, colours, flavourings or sweeteners.
It is the first time that Pepsi has added a new drink to its range for more than 10 years.
The calorie content of a 300ml bottle is 117 compared to 126 for normal Pepsi.
Pepsi Raw has only natural ingredients including apple extract, plain caramel colouring, coffee leaf, tartaric acid from grapes, gum arabic from acacia trees, cane sugar and sparkling water. It is paler in colour and less fizzy than other cola brands.
The company hopes that the introduction of Pepsi Raw will compete for a greater share of the cola market from the leader Coca-Cola and at the same time it will capitalise on the growing consumer demand for more natural products.
The UK cola market is worth £6 billion a year and is dominated by the two companies that have been rivals for more than 100 years. Currently Coca-Cola outsells Pepsi in the UK soft drinks market. Coca-Cola held on to its position as the UK’s most valuable grocery brand in 2007.
Pepsi marketing director, Bruno Gruwez, said: "We are really proud that the UK is leading the way with the launch of Pepsi Raw, which is the most significant innovation from Pepsi UK in the last 15 years.
"Responding to consumer trends towards premium and more natural products, it contains no artificial preservatives and is made using ingredients from natural sources. By launching Pepsi Raw in bars and clubs, we hope to engage with customers in a new way and are confident that they will enjoy its sophisticated cola taste."
Initially, Pepsi Raw will only be available in selected bars and clubs in seven cities – London, Manchester, Glasgow, Brighton, Birmingham, Leeds and Liverpool, although a wider roll-out is expected later in the year.