I am a 32 yo, 5'6" female, weighing 255 lbs (sometimes 253 depending on the day!). I was on Phentermine for 4 months, beginning in February 2015. I have lost almost 20 lbs since then (starting weight was 273- my heaviest ever). Since Phen alone is only approved for short-term use, my doctor has switched me to Qsymia. I went immediately from taking 37.5 mg of Phentermine to the 2 week starter dose (3.75 mg) of Qsymia (Phemtermine/Topimax). I lost MAYBE 2 lbs. I'm wondering if my previous tolerance/plateau with Phentermine (since I literally was on Phen one day and started the low dose of Qsymia the next) may be the reason I'm not really seeing a drastic weight loss immediately (like I did with Phentermine and like I see other people claiming with Qsymia). I am eating as I was on the Phentermine, but I'm hoping that today, when I start the 7.5 mg of Qsymia I begin to see more results. I've heard amazing things about Qsymia and I was pleased with Phentermine, but Qsymia is long-term, too. Has anyone else encountered a slow start to Qsymia, but then a steady weight loss? I'm afraid my tolerance to Phentermine may hinder my Qsymia preogress- and it's EXPENSIVE!! Thanks for any input!! :)