Any ingredient that has a drying effect on your skin will have an even worse effect on your scalp!
Fatty alcohols like stearyl, myristyl and cetyl are moisturizing; other types of alcohol are drying, such as denatured alcohol, propanol, ethanol and isopropyl.
Be sure to check the list of ingredients in the hair products you buy and avoid the ones with drying alcohols.
Salicylic acid can be found in products that treat flaking scalps, but these products should be used sparingly – no more than once per week. Menthol is another ingredient to use in moderation; while it can have a cooling, refreshing and invigorating effect (like peppermint), it can also cause itching in sensitive scalps.