This is a rinse-off treatment, so use it after shampooing. Squeeze or towel-blot the hair so it is damp but not soaking wet, then work a small handful through the mid-lengths and ends. Massage the remaining product lightly into the scalp and roots, where the ginger root oil may create a gentle warming sensation. Leave it on for about 5 minutes, then rinse thoroughly.
For frequency, a practical starting point is once or twice a week, replacing your usual conditioner or mask on those wash days. The formula is silicone-free, so it softens and detangles without leaving a heavy coated finish, which can be useful if you wash often or have fine hair. If your hair feels weighed down, use it less often; if it feels dry, you can apply your regular leave-in conditioner after rinsing.
Pay attention to your skin's response, especially because ginger oil is a warming essential oil. Avoid the eye area and stop if irritation or allergy appears. If you know you are sensitive to warming skincare ingredients, do a small patch test behind the ear before the first full application.