There are various causes of having dark lips-

• Genetics, smoking, lip licking, dryness, sun exposure, dark lipsticks, pregnancy, and medical conditions like B12 deficiency or thyroid issues.

To prevent darkening,

• Avoid lip licking, keep lips moisturized with SPF lip balms, use gentle exfoliation, opt for lighter non-matte lipsticks, and consider treatments like topical creams, chemical peels, Qswitch NDYAG laser, lip boosters, lip fillers , lip micropigmentation.