An implantable medical lead comprising: a lead body having a lumen with a conductor coil running in said lumen; a proximal lead portion comprising a connector pin connected to a first end of said conductor coil and connectable to an implantable medical device; and a distal lead portion comprising: a tubular header having a lumen; a shaft having a second end mechanically and electrically connected to a second end of said conductor coil; a fixation helix at least partly provided in said lumen of said tubular header, said fixation helix being mechanically connected to a first end of said shaft; a tubular coupling mechanically connected to said tubular header, said tubular coupling being coaxially arranged relative to said shaft and having a lumen in which a portion of said shaft is running; a rotation-to-translation transforming element configured to engage said fixation helix and transform a rotation of said fixation helix into a longitudinal movement of said fixation helix relative to said tubular header and said tubular coupling; and a friction device in the form of a circumferential or circumferentially distributed element arranged a) between said shaft and said tubular coupling in a1) a circumferential groove in an outer surface of said shaft, or a2) a circumferential groove in an inner surface of said tubular coupling, or b) between said shaft and said tubular header in b1) a circumferential groove in said outer surface of said shaft, or b2) a circumferential groove in an inner surface of said tubular header, to oppose rotation of said shaft relative to said tubular header and said tubular coupling, characterized in that said friction device is in the form of a homogenous 0-ring of an elastically deformable, flexible polymer-based material. a lead body having a lumen with a conductor coil running in said lumen; a proximal lead portion comprising a connector pin connected to a first end of said conductor coil and connectable to an implantable medical device; and a distal lead portion comprising: a tubular header having a lumen; a shaft having a second end mechanically and electrically connected to a second end of said conductor coil; a fixation helix at least partly provided in said lumen of said tubular header, said fixation helix being mechanically connected to a first end of said shaft; a tubular coupling mechanically connected to said tubular header, said tubular coupling being coaxially arranged relative to said shaft and having a lumen in which a portion of said shaft is running; a rotation-to-translation transforming element configured to engage said fixation helix and transform a rotation of said fixation helix into a longitudinal movement of said fixation helix relative to said tubular header and said tubular coupling; and a friction device in the form of a circumferential or circumferentially distributed element arranged a) between said shaft and said tubular coupling in a1) a circumferential groove in an outer surface of said shaft, or a2) a circumferential groove in an inner surface of said tubular coupling, or b) between said shaft and said tubular header in b1) a circumferential groove in said outer surface of said shaft, or b2) a circumferential groove in an inner surface of said tubular header, to oppose rotation of said shaft relative to said tubular header and said tubular coupling, a tubular header having a lumen; a shaft having a second end mechanically and electrically connected to a second end of said conductor coil; a fixation helix at least partly provided in said lumen of said tubular header, said fixation helix being mechanically connected to a first end of said shaft; a tubular coupling mechanically connected to said tubular header, said tubular coupling being coaxially arranged relative to said shaft and having a lumen in which a portion of said shaft is running; a rotation-to-translation transforming element configured to engage said fixation helix and transform a rotation of said fixation helix into a longitudinal movement of said fixation helix relative to said tubular header and said tubular coupling; and a friction device in the form of a circumferential or circumferentially distributed element arranged a) between said shaft and said tubular coupling in a1) a circumferential groove in an outer surface of said shaft, or a2) a circumferential groove in an inner surface of said tubular coupling, or b) between said shaft and said tubular header in b1) a circumferential groove in said outer surface of said shaft, or b2) a circumferential groove in an inner surface of said tubular header, a) between said shaft and said tubular coupling in a1) a circumferential groove in an outer surface of said shaft, or a2) a circumferential groove in an inner surface of said tubular coupling, or a1) a circumferential groove in an outer surface of said shaft, or a2) a circumferential groove in an inner surface of said tubular coupling, or b) between said shaft and said tubular header in b1) a circumferential groove in said outer surface of said shaft, or b2) a circumferential groove in an inner surface of said tubular header, b1) a circumferential groove in said outer surface of said shaft, or b2) a circumferential groove in an inner surface of said tubular header, to oppose rotation of said shaft relative to said tubular header and said tubular coupling,