After an initial RMR test we recommend scheduling your first retest within 6-8 weeks. If the initial test was within normal ranges then 6-8 weeks allows ample time to make nutritional and/or exercise related adjustments and see tangible results. If the initial test identified a slow or sluggish metabolism and/or a poor fat burning capability, then 6-8 weeks allows time for these issues to be addressed and confirmed via retesting. Since resting metabolic rate does change with weight loss or muscle gain, we usually recommend a second retest 3-4 months after the first retest and a third retest 6 months after the second retest.