The supplement dispensing mouthguards disclosed herein include one or more supplement cavities that store a supplement and one or more openings connected to the supplement cavities. The openings receive the supplement into a mouthguard and discharge the supplement from the mouthguard into a users mouth. The supplement dispensing mouthguards may be worn during physical activity for protection and/or jaw alignment. Once a desired supplement has filled, been inserted, or placed within the mouthguard, the mouthguard is inserted into the users mouth and the supplement is gradually and safely dispersed into the users mouth through openings in the mouthguard.