Processing times vary by formula: quick-deposit conditioners may take about 5 minutes, many products list 15, 25, or 30 minutes, and some permanent creams can require up to 35 minutes. Follow the development time listed on the product.
Apply the mask to clean, dry hair and saturate strands for even coverage. Leave it on for the product's recommended development time (for example, 15 minutes), rinse until the water runs clear, then style as usual.