Research has shown huge potential with adult stem cells. One supplement I have used is called StemEnhance which uses an organic algae to help the body to naturally release stem cells to heal itself.
I've heard of this being effective for a wide range of conditions. I would suggest your son trying it for 3 or 4 months. He can also probably take a dosage of 6 to 9 tablets rather than the 4 suggested. This is still safe. Any questions, let me know.
www.stem-cell.co.uk