The invention relates to a device for extracting and obtaining blood plasma and/or fat, comprising a syringe (1) formed from a hollow cylindrical body (2), with a luer-lock type (3) for coupling a needle (4) or a hermetic closing cap (5), and open on the opposite side, containing a plunger (6) that moves inside the body and has a hollow head (7) and a rod (8) that are brought together by means of screwing and can therefore be separated in the same way. The threaded rear end (9) is complementary to the threaded front end (10) of the rod (8). In its maximum extraction position, the head (7), together with its screwed rear zone (9), coincides with the end of the cylindrical body (2) of the syringe (1).
