My son was on similac soy based. He couldn't tolerate the regular formula or even the reg sensitive. But he's fine with milk now n no soy just because its not part of my cooking.

I have several that were sensitive to regular formulas. I used Gerber Good Start formulas. They worked well for the kids and they didn't have the side effects from using the soy. (Tried those too.) My oldest did much better off of the soy.

No, I produced as milk breast milk as I could for my twins and we had to supplement with enfamil sensitive (which is not soy based)
Out of curiosity, why do you ask?

I was just curious. My son was on soy-formula and I have read a lot research that soy is not a safe product to consume for infants. Also my son was recently drinking soy milk everyday pretty much; and he seemed in such a cloud. His eyes where never clear when he would make eye contact. We took him off of all soy-products an he is very different. He is finally present and aware of his surroundings. We also added GF to his diet and is helped as well. I was just wondering if anyone had this experience.

We went through many types and brands of formula to help my oldest son's reflux. Nestle's Soy formula ended up working best, but it wasn't a fix all.