A couple of winters ago in Granby I as struggling to sleep for the 3rd night in a row. That combined with hard days of activity was draining and frustrating. Surfing at 2am I searched on "altitude sleep" and discovered melatonin. I had certainly heard of that before but never thought about it as something for me. However, I was desperate and so went the next day to a vitamin shop and picked some up. I don't use it at home but it is now standard for me at altitude. I presume that if I stayed at altitude for a couple of weeks it would no longer be necessary, however, I never have that luxury.
I’ve never needed it, but it sure helped Yaya sleep. There don’t appear to be any negative side effects as long as you make sure you really do have a good block of time to sleep (it’s not easy to wake up from if your sleep gets cut short).
I'll think about giving it a try next time. More likely, I'll completely forget about it until after I've had a few nights of bad sleep.