Did the Cosmelan-peel formulation change? Was told it was reason local spa stopped offering Cosmelan peel.

Just called the spa where I got a Cosmelan peel a couple of years ago and was told the spa no longer offers it because the formulation changed and/or some of the ingredients have been flagged by the FDA. Can someone confirm this? Thanks! I'd like to get a second Cosmelan peel but not if the formulation has changed.