The product is a leave-in spray, so it stays on the hair and is not rinsed out. The manufacturer suggests two main ways to use it: spray onto damp hair before blow-drying, or apply onto dry lengths when you want more shine and easier styling. In both cases, aim the spray at the lengths rather than the roots if you have fine hair or a sensitive scalp, because leave-in products can build up quickly at the scalp.
Start with one or two light sprays and distribute them with your hands or a wide-tooth comb. You can always add more, but it is difficult to remove excess once it is on the hair. The formula contains acids and fragrance, so overapplying is not recommended, especially on very fine hair or a sensitive scalp. Avoid spraying into the eyes. If your hair is extremely dry or freshly lightened, use a smaller amount first and check how the lengths respond before adding more.
Because this is a leave-in finishing product, it does not replace your usual rinse-out conditioner. Use it after washing, before heat styling, or as a quick refresh on dry hair between washes. If you use a hairdryer, straightener or curling tools, apply it before the heat step so the light film from Polysilicone-29 is already on the strands.