I tried the Optifast and it did help get me started. I ended up only completing 5 weeks on the program. I lost 21 pounds. I've been off of it for a month now. I gained 8 lbs back originally even though I stuck at 1500 calories or less a day. I'm down 4 of those pounds again.
The drinks and bars are tasty and take a LOT of guess work out of eating habits. I think if I was single, it would have been easier to complete the program fully. It was too hard for me to still prepare food for my husband and son though.
I don't know where you are, but the center I went to was part of the local hospital. From my talking to a lot of people each week, what the team didn't tell me outright was that only 5% of Optifast patients keep it off. That's what made me decide I needed to just make healthier choices on my own.
I wish you a ton of luck! It does work to lose weight, that's for sure.