Lips thin over time due to several factors. The natural aging process leads to a gradual loss of collagen, elastin, and hyaluronic acid, which are essential for keeping lips plump and hydrated. Sun exposure accelerates this breakdown, causing lips to lose volume and develop fine lines. Smoking also contributes by restricting blood flow and damaging collagen fibers. Additionally, repeated facial movements and genetic factors can influence how quickly lips lose their fullness.
