I don't know exactly what about it you want to know. You said you had used it before so it may have worked for you. The only thing I can say is that I used it and hated it. It just got in the way and when I took it off it smelled so bad. Just like leaving a bandaid on for one month, uuuuhh!
But a lot of people don't have a problem with it.

Ive been on the patch for about 5-6 months. I like it, you keep it on for a week and it doesnt get in the way. I always put it on my shoulders, alternating right and left. I tried putting it on my abdomen, but it fell off after three days from my pants/ underwear rubbing against it. The only tow things that I have to complain about are that after you take it off it still has that like blye sticky stuff(like after you take a bandaid off) but its never really smelled. I also started having daily headaches, so I would take advil ever single day. I later found out that from taking advil everday for these headaches that wouldnt go away, I was actually addicted to the advil. Besides headaches for the first few months (mine are pretty much gone now) and for the sticky stuff, I like the patch. Hopes this helps.

I have been using the patch for about 5 months now, and I love it. It is so convenient, you don't have to worry about remembering to take a pill everyday. I have never put it on my shoulder. I usually put it on my abdomin or my butt. But, when I put it on my butt sometimes the corners roll in, and they get stuck to my pants. Other than that, its great. It is just as effective as the pill. I have never had a patch come off, but if it does you can go to the pharmacy and pick up an extra. The only thing about using the patch is that you have to think ahead of time, where you are going to put the patch, according to the activities you are going to do for the week. You don't want to put it on your back, if you are going swimming or wearing a tank top, you know!