Can shape up oil (not pills) products help to reduce belly or thighs fat? is there any side effects if i use it daily? thank you.

No: There aren't any over-the-counter lotions, creams, or oils that reduce belly or thigh fat. Those products may make skin softer and smoother, but the only way to reduce fat is to use up the fat as fuel. Fat is the body's way of storing fuel. If one eats fewer calories than her body uses each day, they her body will use the stored fat and thus decrease fat in her body.