I had high hamstring tendinopathy that sidelined me for two seasons (2011-2012) but I was able to get it under control and haven't had issues since. This is only my "n of 1" but perhaps it's still helpful because I found some things that didn't work (for me) as well as others that finally did work (for me).
Mine came on only in the left high hamstring and was brought about while I was overdoing speed work during the winter (lots of fast loops on a 200 m indoor track). It came on slowly over a few months and then I distinctly remember one track session where I didn't listen to my body, over did it, and hobbled off the track. I saw an orthopedic/sports medicine guy who told me to do a lot of static stretching and take time off running and it would get better on its own. I'm now convinced that advice put me back many, many months. Simply taking time off didn't promote any healing, and lots of static stretching probably aggravated it more than anything else.
Saw a second orthopedic, they recommended a PRP injection, tried that, no change (except for my wallet).
Finally I went to a 3rd sports med person who recommended progressive eccentric loading along with some soft tissue work. The eccentrics progressed from bridges to exercises with a Swiss ball and finally Nordic hamstring curls. (I can give more specifics if you want but it mostly followed the recommendations in: https://www.ncbi.nlm.nih.gov/pubmed/20086362
). Once I was consistently doing eccentrics I was able to start jogging/running again and building up miles. It still took some time before I felt "normal" again, probably around 3-6 months, but progress was steady.
I think my recovery would've been much faster if I'd started with eccentrics and soft tissue work right from the start rather than wasting about a year doing essentially nothing and then crossing my fingers with PRP.