Primrose Lodge offers fentanyl rehab programmes ranging from two weeks to twelve weeks. However, it is strongly recommended that you opt for the longest treatment plan you manage. A two-week fentanyl rehab programme will be start the foundation of your routine and help you through step one and two of the twelve steps. It is strongly recommended that you opt for a longer treatment plan, as this gives you the time you need to break those unhealthy behaviour patterns. Failing this, more dedication to aftercare and group work after a two-week programme can help you stay on track.