A bottle includes a base, neck that defines an aperture, and a body. The bottle has at least one indent in the body that projects into an interior of the bottle and extends around at least part of a circumference of the body. This at least one indent is configured to agitate a substance contained in the bottle. For example, the bottle may contain a powder, such as protein powder, and the at least one indent helps mix the powder with a liquid. In an example, two indents are used in the bottle.