This serum is designed as a leave-in product, so it is meant to stay on the scalp and hair after washing. The usual order is to use it after shampooing, on towel-dried or dry hair, before styling. Start with a small amount, because the formula is concentrated and a little goes a long way.
Part the hair into sections so the scalp is visible, then apply the serum directly to the root area rather than the lengths. Use your fingertips to massage it in with gentle circular movements. This helps the product spread evenly and gives the scalp a fresher, more energized feel. You do not need to rinse it out.
After application, you can comb through the hair if you want a more even distribution, but the serum is mainly aimed at the roots. It can be used after every wash or every other day, depending on how your scalp feels. If your hair is fine or you prefer a lighter finish, use less. If your scalp feels dry, a slightly larger amount is fine. The texture absorbs quickly, so you can style right away.
For best results, use it consistently as part of your hair routine. It is a cosmetic product, so the effects are about appearance and feel rather than a medical change. If you use other scalp products, apply them in a separate step so the serum is not diluted.