Supplementing with formula

I was just at a get together and all of my friends suggested I supplement with formula at night. It came up because I mentioned that bedtime is hard because he is too tired to eat but can't fall asleep because he is hungry. my Supply is low at night so I think he may not be getting enough calories before bed. I'm thinking about trying it but he is sensitive to Dairy so I'm not sure which formula brand to get. Does anyone supplement before bed? And what formula do you use?