Check with your podiatrist, he should know since he's the one prescribing them. Medical supply store can also be a reference. There are many websites that have information on where to buy.
Check with the local medical supply store affiliated with your local hospital/ medical group. This would be the most convenient place to check, outside of the prescribing doctor's office.
You can find them at footlevelers. com or you can try a store that specializes in orthopedic shoes. The Sand Dollar shoe store where I live carries them.
