I keep growing my moustache, then shaving it off. I use an oxygen concentrator at night because of COPD. The little tubes that protrude into my nose, causes the hairs on my moustache to turn up and tickle my nose. After about 5 to 7 weeks, the hair begins to really bother me. I just shaved my moustache down to about a sixteenth of an inch long about 3 days ago. Now I'm good for several more weeks. lol