Embodiments of a testing method suitable for diabetic persons to optimize their administered insulin dosage comprise collecting one or more sampling sets of biomarker data, wherein each sampling set comprises a sufficient plurality of non-adverse sampling instances and wherein each sampling instance comprises an acceptable biomarker reading at a single point in time recorded upon compliance with adherence criteria, determining a biomarker sampling parameter from each sampling set, comparing the biomarker sampling parameter to a target biomarker range, calculating an insulin adjustment parameter associated with the biomarker sampling parameter if the biomarker sampling parameter falls outside the target biomarker range, adjusting the insulin dosage by the insulin adjustment parameter if the biomarker sampling parameter falls outside the target biomarker range and if the insulin dosage does not exceed maximum dosage, and exiting the testing method if the adjusted insulin dosage is optimized. The insulin dosage is optimized when one or more biomarker sampling parameters fall within a target biomarker range.