Beta-sitosterol is for enlarged prostate as men get older.
Regharding stretching, I have multiple lower back muscle injuries. I’d advise exerstretching rather than static stretching.
Just tossing this out - the best stuff I know of for prostate problems is a traditional Ayurvedic formula called Gokshuradi guggulu. Many men I know have totally solved BPH - got numbers down, all symptoms gone, etc. It has other uses as well.