What does USP stamp mean on supplements ?

As a pharmacist I am always asked to pick a vitamin brand for patients to buy! Although there are some brands that are well known, I usually tell my patients to pick a brand that has USP verification mark on the bottle. The USP stamp on a bottle of supplement/vitamin indicates the product contains the ingredient listed on the label. The USP verification helps assure costumers are getting the value they expect from a product they are purchasing. Next time you are buying a vitamin/supplement make sure you see the USP stamp verification on it.