Sermorelin taken one to two nights per week may increase deep sleep but reduce REM sleep.

“I'll just be completely forthcoming I've taken cellan on and off for the last couple of years I typically will take it anywhere from one to two nights per week and I stop taking it almost completely I'll still take it every once in a great while but the reason I stopped taking it is that I noticed that it made the sleep in the early part of my night very very deep very robust but then I would wake up wide awake or I would sleep till morning and then at least according to my eight sleep sleep tracker or my whoop sleep tracker I wasn't getting nearly as much rapid eye movement sleep as I normally would”