The health and skincare company said the review would not include North America, and will be across its consumer, pharmaceutical and medical device businesses and brands.
GroupM and UM picked up the business in 2012 when it was said to be worth £200 million. GroupM created Primus within MEC to handle the account in the UK, France, Germany, Russia, Central and Eastern Europe.
UM handles the account in Spain, Italy, Portugal, the Middle East, North Africa, Pakistan and the Balkans.
A spokeswoman from Johnson & Johnson said: "Our goal is to ensure we have the best media capability in strategy, planning and buying against evolved business strategies and marketing frameworks for Johnson & Johnson’s business sectors and brands around the world."