An implantable medical lead has a distal lead portion with a tubular header and a fixation helix provided in a lumen of the tubular header. The fixation helix is connected to a shaft attached to a conductor coil. A tubular coupling is connected to the tubular header and is coaxially arranged relative the shaft, with the shaft in its lumen. Rotation of the conductor coil causes rotation of the shaft and the fixation helix and longitudinal movement of the fixation helix out of the implantable medical lead by a rotation-to-translation transforming element. A friction device is arranged between the shaft and the tubular coupling or between the tubular header to oppose rotation of the shaft relative the tubular header and the tubular coupling.