 The preferred injection site is the crook of the elbow (i.e., the Median cubital vein), on the user's non-writing hand.Other users opt to use the Basilic vein; while it may be easier to "hit", caution must be exercised as two nerves run parallel to the vein, increasing the chance of nerve damage, as well as the chance of an arterial "nick".Risks from drug injection are caused by a variety of factors, including unclean or unsafe injection practices and repeated injections at the same site.