An automatic injection device for providing a subcutaneous injection is disclosed. The device includes a syringe movably disposed in a housing and including a barrel portion, a needle and a bung for sealing the barrel portion. The device includes a plunger for moving the syringe towards a first open end of the housing such that the needle projects from the first end and subsequently applying pressure to the bung. The plunger includes a rod connected at a first end to the bung, a compressible expanded central portion, and a flange between a second end of the rod and the central portion. The device includes a biasing mechanism for biasing the plunger towards the first open end of the housing, the biasing mechanism disposed about the second end of the rod between the flange and the second end of the housing.
