Greens co-leader Metiria Turei said the party caucus had decided to remove Mr Browning's responsibility for the natural health portfolio.
The portfolio would be merged into the health portfolio, which is held by Kevin Hague.
Mrs Turei said the demotion sent a signal that the Green Party took an evidence-based approach to health issues, especially public health issues.
She said the move was about "rebuilding confidence" in the party.
Mr Browning last week signed a petition started by Australian Fran Sheffield which called on the World Health Organisation (WHO) to "End the suffering of the Ebola crisis. Test and distribute homeopathy as quickly as possible to contain the outbreaks".
Mr Browning said today he did not oppose homeopathy "on a personal level" but he accepted his caucus' decision.
"We are in politics and issues come up. But I am real happy to get on with my other portfolios and you'll see me perform on those."
By Isaac Davison of the New Zealand Herald
