I'm using Citra by Nail Tek. Says on the bottle that it's formaldehyde free. I've been using it for a few weeks now, trimming off the peeling ends as they grew out. Last weekend I gave in to my need for color and put polish over a couple coats of the Citra. The peeling nails looked good before I did that, so hopefully I'll have something good to report when I remove the color. I'll try to remember to update as I go.