"Nestle is proud to be the only major confectionery company in the UK to be 100 per cent free of artificial preservatives, flavours or colours across the entire portfolio.
"To achieve this, Nestle UK and our suppliers have worked very hard ensuring we don't compromise and we maintain the same quality and taste of all our brands."
The changes were made in response to consumers demanding fewer artificial ingredients, Nestle said.
In 2010, Nestle announced it would stop buying palm oil from suppliers linked to plantations or farms that was contributing to deforestation.
The company said it had already set a goal to ensure that by 2015 all of the palm oil it uses comes from sustainable sources.