Salves, ointments and creams have been used through the years to treat many conditions topically. These preparations combine a medicinal herb (or combination of herbs) with an oily base to be used externally. Creams are light and slightly oily, and are designed to blend with the skin's secretions to allow the active ingredients to penetrate the skin. The heavier and oilier salves and ointments are designed to apply protective remedies to the skins surface and require a much longer time to penetrate.