Thanks for that link Caroline.

I am not as old as you but have begun to develop signs of OA, mainly in my shoulders.

I would be very cautious about ozone therapy. Ozone is a powerful oxidising agent so applying it to a joint which has been damaged through OA could lead to oxidative damage to that tissue, making things worse, not better. I can't see anything in PubMed which suggests otherwise.

A couple of other thoughts, all quotes taken from the link and links therein that you gave:

"An inexpensive medical miracle created by a genius functional medicine doctor can save people the expense and pain of having knee replacements and other such operations. [my emphases]"

In my experience evidence-based health professionals don't use words like "miracle" and "genius" very often though they are often used by comp/alt medicine people.

"[Dr Shallenberger] has authored numerous papers in the international peer reviewed literature on ozone therapy and oxygen utilization."

This is wrong. A PubMed search ("Shallenberger") shows 91 peer-reviewed papers, none of which relate to ozone therapy/oxygen utilization. Again, this concerns me - why would an alleged health professional make such a unsupported claim unless s/he was hoping to sell products? I note that Dr Shallenberger's Web site includes a "Shop" in which visitors are invited to buy various things.

Hope this helps.