RSR38 said:
Is it pointless to use the stronger version even if my scalp tolerates it well? Could I do more harm than good? Are there any studies of Retin A that used different strengths and had any increased benefit or negative consequences for higher dose?
The Bazzano study is the only one I'm familiar with which tested Retin-A for our special purpose, so I'm not aware of any that tried different strengths. You could very well do more harm than good, if you are not VERY VERY CAUTIOUS about increasing the dose. Stop immediately (temporarily), if you start to get any kind of irritation.