Where can I buy over-the-counter tummy tightening cream?

All I can find are tightening creams for the face, which may not work on my belly and will only come in small containers. A lot of sites online say to use over-the-counter tummy tightening creams to tighten skin on the stomach, but where the hell do I get them?? Is there a health store I could go to? I'd prefer to physically get it from a store, not order online. Please help, and ONLY answer if you know. Yes, I'd be using it in addition to diet and exercise. I have loose skin and stretch marks from having my son 3 years ago.