I have not tried it but a lot of people will tell u that u should do it all natural which is in truth the hardest way and probably the most effective, long term, if u are committed enough and have enought willpower - who does.
I have personally been thinking about trying these and have done a bit of research on them. First, thing I hear is always have a doctor supervise u, but in truth once u notice any of the symptoms listed as dangerous reactions, u should stop taking them right away. U might also notice some minor ones which are fine for some but check them for urself to see if their fine for u. One thing I didn't like that was listed, in reliable websites, is stuff like hair loss can occur; no sudden effect from taking the pills ( which is possible but can be due to low dosage or personal issues), it can cause insomnia, and the fact that it can show up as an Amphetamine on drug test - may be significant career wise- (the chemical make up is similar but while not technically one it is one in nature and in my opinion it's one plain and simple, so take it if u like, as I may, but be very very careful).
From what i've read, it works by making u feel as if u are not hungry. U also need to know that these things, and i say this cause it's true, that they are addictive. Once, u get off them u could feel depressed and have such symptoms after getting off any thing that is addictive. Also, a lot of people who take them do gain weight back after stopping (which u will have to stop after a max of 3 months), so forming good nutrition and exercise habits and keeping them up throughtout and after are of vital importance. It seems more benefical to me to stay on them at most about a month to 6 weeks and get off them for a while, then go back on later after u made some decent lose without the pills, if u have to go back on. They are good to get u going though, cause they can give u a kick in energy, and since ur seeing results it may make u realize that losing weight is possible. Lastly, u can become tolerant to these things, some do so rather quick after a month, others take longer. Some lose significant weight quick throughout, others only the first week or two and then they lose more slowly at about 2 lbs a week thereafter.
Remember to check it out on sites like webmd and other such reliable sites to be very sure u know what u are taking into ur body.
So if u are using it as a mircale drug then don't take it cause it will fail u and u will only end up heavier and worse than u are now, that's the honest truth. If u are already working out and eating health right now, and tried a lot of stuff in the past to lose weight but that failed, then they can be very useful. If u are going to workout and eat healthier during, then they can still be valuable but without the diet and exercise throughtout its useless. Also don't forget since ur on them feeling less or no hunger seems easy but since u need to get off them it can get scary once u do, cause how will u do without them. That's why working out and eating healthy before getting on them is a lot better for your long term success. If u are not going to eat at all and/or eat healthy when taking them, and exercise, then u are settig urself up for failure plus worse than u were before results. The point is to have success after and so forth so try to set yourself up for a successful outcome and this has to take into account not only a year but many many years. Good Luck with ur program and meds.