Carboxytherapy can dramatically improve the appearance of dark under-eye circles. Although sometimes caused by darkened pigment, or a hollow depression below the lower eyelids [tear trough deformity], the majority of dark under-eye circles are caused by poor circulation beneath the lower eyelids [vascular pooling. Injecting a small amount of carbon dioxide gas just beneath the skin of the lower eyelid, circulation was increased and dark under-eye circles were markedly improved. The treatment takes only five minutes, and is virtually painless and risk-free. A series of 2-8 treatments spaced one week apart is all that is required to achieve a great result.