I use it for the lay boxes and as a substrate for my planted tanks which house day geckos, a crested gecko and a pair of fat tails. I don't think it would be a problem for leopard geckos, if it's not a problem for fat tails, but there will probably be disagreement. I would be somewhat concerned with leopard geckos that it would be too crumbly if dry and too humid if wet. I prefer tiles.