Doctors will give various answers to this and we probably don't have enough information yet to know how low is safe for long term ferritin levels when using various chelators. With Exjade, much depends on how often monitoring takes place. If liver and kidney tests are run weekly, a ferritin of 300 should be safe, If tests are less frequent, then 500 may be a better goal. My feeling is lowering the dose to a maintenance level dose may be the best plan, so there are never any chelation gaps. 20 mg/kg should be sufficient when ferritin is below 500.