How long should I leave the mask on for the best result without overdoing it?

After shampooing, squeeze out excess water so the mask can adhere to the hair fibre rather than slide off. Distribute a generous amount through damp lengths and ends, then wait three to five minutes before rinsing thoroughly with lukewarm water. For hair that is very dry, thick, coloured, or frequently heat-styled, leaving the mask on for up to ten minutes allows the aloe polysaccharides and ceramides more time to form a hydrating film and reinforce the cuticle layer.

There is no advantage to leaving it on for 20 or 30 minutes; the active ingredients have already saturated the hair surface by that point, and prolonged contact can make rinsing harder or leave a slight residue on finer textures. If you accidentally leave it on longer, simply rinse well — no harm done, but no extra benefit either.