This serum is meant for the lengths and ends, not for the scalp, so a sensitive scalp does not automatically rule it out. The main thing is to keep the product away from the roots and any irritated or broken skin. Apply it only from the mid-lengths downward, and if your hair is short or you cannot easily avoid the scalp, use a very small amount and wipe your hands rather than rubbing the product into the skin.
The formula contains fragrance components and UV-filter ingredients, which are common sources of irritation for some people. If your scalp is already sensitive, red or itchy, it is better not to apply the serum to the scalp area at all. If you have a known sensitivity to fragrance or to sunscreen-type filters, check the ingredient list before use and consider testing the product on a small area of skin first.
Discontinue use if any discomfort, redness or itching appears. If you have a scalp condition or active irritation, consult a specialist before using any leave-in product on or near the affected area. This serum is a cosmetic product for hair care and is not intended to treat or prevent any skin condition.