How Melanin Overproduction Darkens the Lips Excess melanin production is one of the main reasons for lip darkening, particularly in people who are regularly exposed to extrinsic and intrinsic stimulants like sun exposure, hormonal fluctuations, smoking, or medications
Physiol 128:105658 [DOI] [PMC free article] [PubMed] [Google Scholar] 168.Smets J, Baeyens F, Chaumont M, Adriaens K, Van Gucht D
The competition Reusable respirators The 3M Rugged Comfort Quick Latch reusable respirator, a former pick, is widely used and highly rated, but its complex features are a hindrance rather than a help
Or having to wait for someone while they run outside for a quick cigarette, which is never really quick, because a few puffs are never enough, and the idea of wasting a full-length cigarette just for 3-4 drags is a no-no to them