A syringe assembly (101, 300, 400, 500) comprising: a fluid barrel (110, 210, 230, 310, 410) including a sidewall (112, 312) having an inside surface (114, 314) defining a fluid chamber (115, 315) for retaining fluid and having a first cross-sectional width, an open proximal end (119, 319) and a distal end (111, 311) including a distal wall (117, 317); a plunger rod (160, 360, 460) disposed within the fluid chamber comprising a distal end, a proximal end (199, 399, 499), a plunger rod body extending from the distal end to the proximal end, and a stopper (160, 170, 370) disposed at the distal end of the plunger rod for forming a fluid-tight seal with the inside surface of the barrel; a retraction barrel (120, 220, 320, 420) disposed adjacent to the sidewall of the fluid barrel, the retraction barrel including a wall (122, 223, 322, 422) having an interior surface (124, 324) defining a needle chamber (125, 325), an open proximal end, an open distal end (121, 221, 321) including a barrier wall, an aperture (123, 232) between the wall of the retraction barrel and the sidewall of the fluid barrel permitting fluid communication between the fluid chamber and the needle chamber and a needle hub assembly (140, 200, 340, 540) comprising a needle hub (142, 342, 542), a needle cannula (150, 205, 350, 550) attached to the needle hub, the needle cannula being in fluid communication with the aperture and biased to move in a proximal direction; and a trigger element (190, 390, 490, 492, 590) disposed within the needle chamber and moveable within the retraction barrel independently from the plunger rod, characterized in that the trigger element includes a proximal end, a free and open distal end that provides the trigger force, and a trigger element body (192, 392, 492, 592) extending from the proximal end to the distal end and including an interior surface defining a hollow interior (193, 393), the trigger element providing a trigger force causing the needle cannula to retract into the retraction barrel. a fluid barrel (110, 210, 230, 310, 410) including a sidewall (112, 312) having an inside surface (114, 314) defining a fluid chamber (115, 315) for retaining fluid and having a first cross-sectional width, an open proximal end (119, 319) and a distal end (111, 311) including a distal wall (117, 317); a plunger rod (160, 360, 460) disposed within the fluid chamber comprising a distal end, a proximal end (199, 399, 499), a plunger rod body extending from the distal end to the proximal end, and a stopper (160, 170, 370) disposed at the distal end of the plunger rod for forming a fluid-tight seal with the inside surface of the barrel; a retraction barrel (120, 220, 320, 420) disposed adjacent to the sidewall of the fluid barrel, the retraction barrel including a wall (122, 223, 322, 422) having an interior surface (124, 324) defining a needle chamber (125, 325), an open proximal end, an open distal end (121, 221, 321) including a barrier wall, an aperture (123, 232) between the wall of the retraction barrel and the sidewall of the fluid barrel permitting fluid communication between the fluid chamber and the needle chamber and a needle hub assembly (140, 200, 340, 540) comprising a needle hub (142, 342, 542), a needle cannula (150, 205, 350, 550) attached to the needle hub, the needle cannula being in fluid communication with the aperture and biased to move in a proximal direction; and a trigger element (190, 390, 490, 492, 590) disposed within the needle chamber and moveable within the retraction barrel independently from the plunger rod, characterized in that the trigger element includes a proximal end, a free and open distal end that provides the trigger force, and a trigger element body (192, 392, 492, 592) extending from the proximal end to the distal end and including an interior surface defining a hollow interior (193, 393), the trigger element providing a trigger force causing the needle cannula to retract into the retraction barrel.