That's another point to consider - these hairloss treatments work to varying degrees of efficacy with those who try them. The AA/Minox combo seems to be working wonders for me, and yet LCSULLA didnt find AA all that helpful. Another reason to try the 'kitchen sink' approach. One product might work better for you than others, they may have varying degrees of synergy when working together, etc.
If your losing your hair, and you want to save it, or if you're going on a cycle and you're worrying about losing it, dont cut corners. After you've seen some regrowth, you can always drop a product here or there and see if the positive effects slow down, etc. At the very least, I would always continue using minoxidil if you are currently losing hair.