J-plasma or tummy tuck? My belly got really wrinkled and loose after pregnancy (Photo)

J plasma will be helpful, but you will get you best and tightest abdomen with the tummy tuck. The tuck can tighten your weak muscles, remove excess fat and pull down the stretched tissue and remove a good portion of skin. The tuck is much more involved and does take longer to heal.

Hi! In reviewing your picture, an abdominoplasty (or tummy tuck) will be the best procedure for you. An abdominoplasty will address several things- muscle weakness (diastasis recti) and create a "snatched" waistline, an innie belly button, low set incision, elimination of the skin redundancy present from the level of the belly button to your pubic region, as well as a pubic lift.
-Dr. Satey

From your photo I would recommend a tummy tuck. This would remove excess fat and skin as well as correct abdominal wall laxity. The result will be a flatter, tighter tummy. Liposuction and J-Plasma would not be able to give you comparable results.