I'd stick with sensitive.

you can try to switch and see how they tolerate it. We were on nutramigen and tried switching around 8 months. It was bad, constipation, vomitting. We were so worried about the transition to regular cow's milk, but by 11.5 months when we first introduced it he was FINE.

You don't have to switch. We switched from Gentlease to the regular Enfamil at around 6 months because of cost and DS had no ill effects.

We did sensitive for 12 months. She is adopted and came to us on SS at 30 days. We say no need to switch so we didnt.

Yeah, you can try. There's no mandate that you have to do that but often the generic or regular infant formulas are less expensive. DS was on gentlease from 1 month to 7 months then we started adding yogurt to the rotation of solid foods around 6 months. Then around 8 months we made the switch to generic Costco brand infant formula and saved a lot of money for months 8-12.

You could try to mix the two together and see what happens, if the gassiness comes back. For a week, do 75% sensitive and 25% regular. For a week, do 50% of each, and then 25% sensitive and 75% regular. Keep an eye out for a change in gassiness, then switch to 100% regular. There's no real risk here - you can always switch back.

Our daughter was super gassy, and because I am lactose intolerant, we started giving her the gentle-ease formula. It worked so we just stuck with it. She did turn out to be lactose intolerant, so that's another possibility for you.

I have been giving my now 6 month old similac sensitive. I gave him sensitive around 1 month because he was very gassy. Do I switch from sensitive to regular at some point? Or do I just continue with sensitive?