Low Intensity/Level Laser Therapy works great on tendonitis-type issues:
Low Level Laser Treatment of Tendinopathy: A Systematic Review with Meta-analysis.
Eccentric exercise accumulated review (you might want to find/buy the whole paper or the studies used in it):
Chronic tendinopathy: effectiveness of eccentric exercise.
You might find it less expensive to invest in your own laser. This one
is not intended
for human use, but it works exactly the same, much like veterinary pharmaceuticals...