What is the primary effect of elastin on the skin?

Elastin is a crucial protein in the skin that contributes significantly to its elasticity. The primary effect of elastin is to allow the skin to stretch and then return to its original shape. This elasticity is essential for maintaining the skin's youthful appearance, as it enables the skin to adapt to movements and flex without losing its structural integrity.

As we age, the production of elastin decreases, which can lead to sagging and the formation of wrinkles. Thus, elastin plays a vital role in how the skin responds to physical changes, ensuring it remains supple and resilient. When considering the other options, while they relate to important functions of the skin, they do not define elastin's primary role. Preventing water loss is more closely associated with the skin's barrier function, promoting firmness is largely the role of collagen, and stimulating collagen production is a different process that is not directly linked to elastin itself.