It truly is a great product and I love it. Had a lot of issues with my stomach from aleve and ibuprophen so the Flexcin has been wonderful for me. You can read about my story here http://www.zerojointpain.com/my-story/
If you do decide to purchase please let me know how your father does? I love to hear about others benefiting a well.
All I can say is check out these videos http://www.zerojointpain.com/videos/
These are real people, that have been on the news and done some amazing things. There are even some more vids on the site as well.
Good luck and God Bless to you and yours as well.
Chris