Medical injection device (1; 33; 41; 56; 58), comprising: - an injection unit, comprising: -- a container for the medium to be injected, -- an injection cannula, which communicates with the container, - a needle guard, which is displaceable between -- an injection position, in which the injection cannula is adapted to be opened up to inject the medium, and -- a safe position, in which a cannula tip of the injection cannula is arranged recessed in a protective component (10; 34) of the needle guard, - a securing device (14; 39, 40) for securely fixing the protective component (10; 34) in the safe position, - an interlocking adapter (13; 36) for connecting the needle guard to the injection unit in an interlocking connection, - wherein the needle guard has at least two telescoping sleeves (10 to 12; 34 to 36; 34, 35, 42), wherein a connecting telescoping sleeve (12; 36; 42) is connected to the injection unit and wherein a protective telescoping sleeve (10; 34) forms the protective component, characterized in that - at least one part of the needle guard is designed as a multi-component injection-molded part, and - at least one multi-component injection-molded part of the needle guard is designed as an outer sleeve, which has at least one grip section and at least one supporting body, wherein the supporting body on the one hand and the at least one grip section on the other hand are designed as different injection-molded components of the multi-component injection-molded part. - an injection unit, comprising: -- a container for the medium to be injected, -- an injection cannula, which communicates with the container, -- a container for the medium to be injected, -- an injection cannula, which communicates with the container, - a needle guard, which is displaceable between -- an injection position, in which the injection cannula is adapted to be opened up to inject the medium, and -- a safe position, in which a cannula tip of the injection cannula is arranged recessed in a protective component (10; 34) of the needle guard, -- an injection position, in which the injection cannula is adapted to be opened up to inject the medium, and -- a safe position, in which a cannula tip of the injection cannula is arranged recessed in a protective component (10; 34) of the needle guard, - a securing device (14; 39, 40) for securely fixing the protective component (10; 34) in the safe position, - an interlocking adapter (13; 36) for connecting the needle guard to the injection unit in an interlocking connection, - wherein the needle guard has at least two telescoping sleeves (10 to 12; 34 to 36; 34, 35, 42), wherein a connecting telescoping sleeve (12; 36; 42) is connected to the injection unit and wherein a protective telescoping sleeve (10; 34) forms the protective component, characterized in that - at least one part of the needle guard is designed as a multi-component injection-molded part, and - at least one multi-component injection-molded part of the needle guard is designed as an outer sleeve, which has at least one grip section and at least one supporting body, wherein the supporting body on the one hand and the at least one grip section on the other hand are designed as different injection-molded components of the multi-component injection-molded part.