How often should I use a deep conditioning hair mask?

Across the reviewers we read, most recommend once a week for normal to dry hair and once every two weeks for fine or low-porosity hair that gets weighed down easily. Color-treated or bleached hair often benefits from twice-weekly use, but specialist haircare communities warn that overusing protein-heavy masks (including bond builders) can leave hair stiff or brittle, so rotating with a protein-free moisture mask is a common recommendation.