Just my opinion here, but using Xandrox 15 once a day is NOT a substitute for using minoxidil twice a day.
Even if you are on the Xandrox 15, you still need to get in that morning app of minoxidil if you are serious about expecting regrowth.
This is perhaps the BIGGEST lesson I have learned about hairloss treatments... Using minoxidil twice a day is critical for regrowth. And believe me, I have been on the sh*t for a LONG time, even dabbling in various forms of designer minoxidil such as Xandrox 15, and have tinkered enough to know that the key to minoxidil regrowth is the twice a day application.
Once a day for maintenance, twice for regrowth
Sounds corny, but it is TRUE.