Are herbs from Lowes and Home Depot safe?

I feel like my bun isn’t as plump as I would like him to be. When I first got him my mom smothered him with different types of treats so he got chonky he wasn’t overweight. I recently just felt his spine and ribs to check and he seems to have lost a tiny bit of weight. I’m thinking about buying some herb plants like parsley,basil, dill etc from Lowe’s or Home Depot but not sure if they are safe. Do they spray the herbs with chemicals to keep the bugs off? Any recommendations on trying to plump him up would be appreciated. I feed him only hay no pellets (they mess with his poo) and very very occasionally treats or veggies because they seem to mess with his poop and he overproduces cecotropes which results into a dirty butt and very stinky poo.

by Competitive_Gur3178