Maryland Cosmetology State Practice Exam

Which ingredient is commonly found in moisturizers to help hydrate the skin?

1. Salicylic acid

2. Hyaluronic acid

3. Tea tree oil

4. Coal tar

The correct answer is: Hyaluronic acid

Hyaluronic acid is widely recognized for its exceptional ability to hydrate the skin, making it a popular ingredient in moisturizers. It is a naturally occurring substance in the body that retains moisture, holding up to 1000 times its weight in water. This property not only helps to keep the skin hydrated but also promotes elasticity and a plump appearance, which can be beneficial for all skin types, especially dry or dehydrated skin. In contrast, the other ingredients listed serve different purposes: salicylic acid is primarily used for its exfoliating properties and is effective in treating acne; tea tree oil is renowned for its antibacterial and antiseptic qualities, often used in acne treatment products; and coal tar is used mainly for its therapeutic benefits in treating conditions like psoriasis and eczema, rather than for hydration purposes. Therefore, hyaluronic acid stands out as the key ingredient specifically focused on moisturizing and hydrating the skin.