What are the differences, and which is best to use?
I'm looking for a good birth control to prevent pregnancy and to control my menstrual cramps as well as acne.

I'm pretty sure the ortho lo is just lower dosage. That's what I'm on and the first week is a rally low dose, the second a little bit higher, and the third just a little higher than the last. Every woman's bod is different so even though I love ortho tri cyclen lo and it works great for me it might not be the right one for you. Its one of those things you have to figure out with your dr and you might have to try a few different pills before you find the right one for you