A medical delivery device is provided for delivering a medicinal substance into a users body. An upper assembly includes a housing having a cavity configured for accommodating a needle. A lower assembly includes a receptacle member having an opening configured for accommodating insertion of the upper assembly, and a base member having an upper body and a recess formed on a top surface of the upper body for receiving the receptacle member. A base pad has an adhesive layer disposed on a lower surface of the pad, and being at least partially attached to a bottom side of the base member. The lower assembly is attached to a skin of the user using the base pad. As the upper assembly transitions from an upper position to a lower position relative to the lower assembly, the needle travels downwardly to penetrate the skin for facilitating administration of the medicinal substance.
