How does "the pill" work? Compare Norplant, Depo-Provera, NuvaRing and Ortho Evra as contraception approaches?

How does "the pill" work? Compare Norplant, Depo-Provera, NuvaRing and Ortho Evra as contraception approaches. How does each work and what is the "failure rate" for each.

I don't know about all of them but I do know that the pill has to be taken daily and at the same time. You miss a day and you increase your risk of getting pregnant. If you are a smoker or over a certain age they do not recommend you take the pill. The patches are recommended for very slim women. Not effective if you are over a certain weight. The Depo-Provera shot is given once every 3 months or 6 months...I forgot which. It has been awhile since I was on it. It is easier to have the shot because it is pretty effective and you only have to worry about it the times I listed above. Although, I do not recommend the shot. It can cause weight gain, some women have heavier periods, some have no periods at all. I had one right before I was due for the shot. It took a long time for my periods to become regular again after getting off the shot. It has also been said to cause Osteoperosis when used for awhile. It made me have symptoms similar to going through menopause. I didn't realize it was the shot making me ill and have other problems until I had been on it awhile.