Which role does witch hazel serve in cosmetic formulations?

Witch hazel is primarily known for its role as an astringent in cosmetic formulations. An astringent is a substance that helps to tighten and constrict body tissues, which can help to reduce oiliness and minimize the appearance of pores. This property is particularly beneficial for individuals with oily or acne-prone skin, as it helps to remove excess oil and can soothe irritation.

Witch hazel is derived from the bark and leaves of the Hamamelis virginiana plant and is often used in toners, lotions, and other skincare products. Its astringent qualities make it effective in promoting a clearer complexion by controlling excess oil production and providing a refreshing feeling to the skin.

The other roles mentioned do not accurately describe witch hazel. It is not primarily considered a moisturizer, as it doesn't provide hydration in the same way humectants do. Additionally, witch hazel does not function as a coloring agent, which is typically found in products designed to impart color. Lastly, it does not serve as a thickener in formulations, which usually involve other ingredients specifically designed to enhance texture and viscosity.