I have used Sam e for SAD combat anxiety and mild depression. I would say that it works fast and it works very well for me. I would highly recommend it although the 400mg gave me stomach pains so I cut them in half. It is possible to purchase 200mg tablets from other stores. Be sure to use Nature Made and take a B complex vitamin when you use Sam e. Take it in the morning at least 1/2 hour before breakfast with lots of water.