Tummy tuck 3 weeks ago and I was wondering if i can use a moisturizer?

Yes, you may apply a moisturizer to the addominal skin 3 weeks after a tummy tuck except the incision. The incision should be treated with some type of  scar care regimen to improve the appearance of the scar with time Best of luck. 

Following a tummy tuck most patients can safely use any skin care products once the incision has healed. Unless there is a problem with healing, which typically occurs after about 10 days, I advise patients that they can put anything they choose on the incision other than ultra violet light or heat.  Coconut oil would be a great choice or any of the creams that help reduce scarring.  Check with your own doctor to be sure.