A synthetic vitamin supplement. Vitamin A (also known as retinol) maintains the immune system and allows certain tissues to heal after taking damage. It also appears to support healthy skin and reduce the size of sebaceous glands, reducing the chances of acne breakouts and some other common types of skin irritation.

Retinyl palmitate is included in some lubricants and massage liquids as a skin-friendly supplement. It is considered a safe ingredient, and side effects are uncommon.