I took BPC157 preworkout because it seems to reduce inflammation to the injury and make the workout better. If you really want to speed things up then post workout is a good idea as well.
If you use HGH then inject the BPC157 prior to the HGH. There appears to be synergy in doing this. 250mcg before and after training is a good protocol. I had good results with once a day though. I used 250-500mcg per day.