16 days post lipo. Tightness at back of thigh, severe pain when I stand up for first couple of minutes. Normal?

I suggest RF treatments, massage, and to continue compression for this time.  Please see an expert.  Best, Dr. Emer.

Thank you for sharing your question and I am sorry to hear of your recovery difficulties.  Though nothing replaces an in-person examination for more definite diagnosis, you are likely either experiencing swelling of your thigh tissues or cramping of your leg muscles.  Both can give patients the feeling of "tightness" and make it difficult to move early in the morning.  I would voice your concerns to your surgeon and continue use of a compression garment for symptom control.  Hope this helps.