Stem cells are progenitor cells which are capable of regeneration and differentiation into a wide range of specialized cell types. Once injected, stem cells follow inflammatory signals from damaged tissues and have multiple ways of repairing these damaged areas. Length of treatment will vary depending on the type of treatment and the disease which is being treated. Most treatments last for 1-4 weeks and consist of 4-6 sessions. However, this number may vary; you may have to repeat the entire course after six to eight weeks and will be determined by your doctor following your initial appointment at the clinic.