THIN OR ASYMMETRIC LIPS
Asymmetric or thin lips are caused due to the underdevelopment of one or both lips resulting in an uneven, thinned appearance.
Visually, full lips are a sign of femininity, and if your lips are thinner than usual, you may feel that they look unappealing or cause you to feel less confident. Thin or asymmetric lips may be due to genetic factors, where the lips have just naturally underdeveloped.
However, they could also be caused by the natural ageing process, trauma to the lips, or metabolic conditions. If your lips are thinning as you age, this occurs due to a loss of collagen around and within the lip area, and the tiring of the muscles around the mouth as we get older.