Can confirm. You walk across the border at Nogales and every other building is a Pharmacy with a guy out front trying to talk any gringo he sees into coming inside.
Lots of drugs that are prescription only in the US are OTC in Mexico.
It's a preppers delight when antibiotics and anti parasitics are sold OTC in 500 pill bottles like aspirin is here.
There are many ways that the US has strayed from It's promise of being "the land of the free".