Generally speaking, when people lose weight, the collarbone will naturally stand out, but some people are born with low collarbone. But the skin of chin, neck and collarbone are all connected. Presumably, the chin skin is tight, and once the clavicle skin is tight, the clavicle should be somewhat prominent. Here is a way to reduce your chin: just look up! Be sure to lift your head hard and feel your chin and neck tighten. Stop for 5 seconds and put it down. Do it 20~40 times a day. You will see the effect in a week.