Hello, Thank you for asking your question at health care magic. Weight gain is a very common side effect of Paxil. Since you have gained almost 20 pounds while on paxil, the issue need to be addressed. If a patient comes to me with this complaint, I will recommend switching to another medication for anxiety which do not cause weight gain like welbutrin (Buproprion), Effexor(Venlaflaxine). Effexor was initially used as an antidepressant ,but now the FDA has approved its use as an anti anxiety medication too. Welbutrin is also an antidepressant, but trial and error has now proved its effectiveness for treatment of anxiety too. Mean while follow healthy eating habits and regular exercise to manage weight. I recommend that you consult with your doctor to discuss regarding different medication options and its side effect profile, so that he/she can decide upon a medication best suited for your individual needs. Hope I was able to answer your question Please feel free to address any more concerns Regards, Dr.Lekshmi