I visited twice during my weekend visit at the cosmo, and i can legit say, their chai seed vanilla pudding is the only thing that worked for my hang over.
If you talk a walk past Eggslut, the other popular breakfast option in the cosmo, you'll find the minimalist store front for The Juice Standard tucked around the corner. Specializing in an array of pre-blended bottled juices, nut milk based smoothies and traditional fruit smoothies, they offer something fresh and clean in the middle of Vegas debauchery. Their vanilla chai seed pudding with granola and banana proved to be a life saver for me twice and their juice was refreshing and cleansing.
Prices are steep though possibly in part because the pre bottled drinks comes in this nice heavy glass milk jars. Since i wasn't going to bring that bottle home in my luggage, i had to throw it out. I would've been just as good if they were packaged in plastic. That said, it gave me my life back so for that reason the juice was priceless.