Thinning Lips

Your lips begin to thin for the same reason your skin begins to sag with time: a natural decline in collagen. Young lips are full because young skin contains plenty of collagen and naturally-occurring hyaluronic acid, which keeps your lips moist and plump from the inside out. Lip size and shape are genetically determined, but all of us tend to get thinner lips over time. If your lips are naturally smaller, you may start to notice thinning in your late 20s and 30s. This is when collagen and hyaluronic acid production start to slow down.