A safety syringe system, comprising: a. a syringe body forming a fluid reservoir and having proximal and distal ends (38, 42); b. a plunger tip positioned within the fluid reservoir in a configuration such that medicinal fluid may be contained within the fluid reservoir; c. a needle assembly comprising a retractable needle and a needle housing (48, 50), wherein the needle assembly is removably coupleable to the distal end of the syringe body such that the medicinal fluid is transferred through the retractable needle (58, 60) upon insertion of the plunger tip into the syringe body, wherein the retractable needle comprises a proximal end comprising a proximal tip interface; and d. a plunger control assembly coupled to the plunger tip and configured to facilitate manual insertion of the plunger tip into the syringe body; wherein upon insertion of the plunger tip to a final insertion state, whereby the proximal tip interface stabs into the plunger tip, and release of an associated manual insertion load, a retraction load coupled between the syringe body and the plunger tip causes the plunger tip to be proximally withdrawn, pulling the retractable needle (58, 60) proximally relative to the needle housing (48, 50) to a retracted state wherein a distal tip of the needle (58, 60) becomes mechanically locked into an encapsulated configuration in the syringe body wherein it is no longer exposed for injection; and wherein the needle assembly comprises a movable needle insertion-preventing member comprising a needle through aperture, and a two-fingered latch member movably coupled to the movable needle insertion preventing member, to prevent movement of the distal tip of the needle (58, 60) out of the syringe body after the needle has been placed in the retracted state, wherein upon full insertion of the plunger tip to the final insertion state, a geometric step of the movable needle insertion preventing member is pushed past the two fingers of the latch member so that the movable needle insertion preventing member is stuck in a position, wherein by virtue of ramp surfaces of the movable needle insertion preventing member, the movable needle insertion preventing member is biased to move in a direction substantially perpendicular to the longitudinal axis of the needle. a. a syringe body forming a fluid reservoir and having proximal and distal ends (38, 42); b. a plunger tip positioned within the fluid reservoir in a configuration such that medicinal fluid may be contained within the fluid reservoir; c. a needle assembly comprising a retractable needle and a needle housing (48, 50), wherein the needle assembly is removably coupleable to the distal end of the syringe body such that the medicinal fluid is transferred through the retractable needle (58, 60) upon insertion of the plunger tip into the syringe body, wherein the retractable needle comprises a proximal end comprising a proximal tip interface; and d. a plunger control assembly coupled to the plunger tip and configured to facilitate manual insertion of the plunger tip into the syringe body; wherein upon insertion of the plunger tip to a final insertion state, whereby the proximal tip interface stabs into the plunger tip, and release of an associated manual insertion load, a retraction load coupled between the syringe body and the plunger tip causes the plunger tip to be proximally withdrawn, pulling the retractable needle (58, 60) proximally relative to the needle housing (48, 50) to a retracted state wherein a distal tip of the needle (58, 60) becomes mechanically locked into an encapsulated configuration in the syringe body wherein it is no longer exposed for injection; and wherein the needle assembly comprises a movable needle insertion-preventing member comprising a needle through aperture, and a two-fingered latch member movably coupled to the movable needle insertion preventing member, to prevent movement of the distal tip of the needle (58, 60) out of the syringe body after the needle has been placed in the retracted state, wherein upon full insertion of the plunger tip to the final insertion state, a geometric step of the movable needle insertion preventing member is pushed past the two fingers of the latch member so that the movable needle insertion preventing member is stuck in a position, wherein by virtue of ramp surfaces of the movable needle insertion preventing member, the movable needle insertion preventing member is biased to move in a direction substantially perpendicular to the longitudinal axis of the needle.