My derma asked me to apply 2%minoxidil twice a day, but online I was reading an article which says I should wait for 24 hours to apply minoxidil. How both things are possible? I am confused now. I have started using 0.2 derma and 0.5mm. I use 0.5 mm twice a week and 0.2 thrice a week. Can I apply minoxidil after waiting 15-20minutes of derma rolling