An apparatus for dosing of a medication, comprising: a sensor (110-124, 170) configured to generate sensor data of a user; a memory storing instructions; and a processor coupled to the sensor (110-124, 170) and the memory, wherein the processor is configured to: receive the sensor data from the sensor (110-124, 170); determine a state of a biological marker for the medication based on the sensor data in a time period, wherein the time period is determined based on a dose time of the medication and information for a half-life of the medication; determine an expected state of the biological marker in the time period based on a baseline for the biological marker to detect a change in the biological marker, wherein the baseline is correlated with at least two segments of circadian cycle for the biological marker of the user; determine whether the user has missed a dose of the medication in response to detecting the change in the biological marker during a time period correlated with the dose time of the medication by comparing the state of the biological marker and the expected state of the biological marker; and provide a notification for indicating the missed dose of the medication if it is determined that the user has missed the dose of the medication. a sensor (110-124, 170) configured to generate sensor data of a user; a memory storing instructions; and a processor coupled to the sensor (110-124, 170) and the memory, wherein the processor is configured to: receive the sensor data from the sensor (110-124, 170); determine a state of a biological marker for the medication based on the sensor data in a time period, wherein the time period is determined based on a dose time of the medication and information for a half-life of the medication; determine an expected state of the biological marker in the time period based on a baseline for the biological marker to detect a change in the biological marker, wherein the baseline is correlated with at least two segments of circadian cycle for the biological marker of the user; determine whether the user has missed a dose of the medication in response to detecting the change in the biological marker during a time period correlated with the dose time of the medication by comparing the state of the biological marker and the expected state of the biological marker; and provide a notification for indicating the missed dose of the medication if it is determined that the user has missed the dose of the medication. receive the sensor data from the sensor (110-124, 170); determine a state of a biological marker for the medication based on the sensor data in a time period, wherein the time period is determined based on a dose time of the medication and information for a half-life of the medication; determine an expected state of the biological marker in the time period based on a baseline for the biological marker to detect a change in the biological marker, wherein the baseline is correlated with at least two segments of circadian cycle for the biological marker of the user; determine whether the user has missed a dose of the medication in response to detecting the change in the biological marker during a time period correlated with the dose time of the medication by comparing the state of the biological marker and the expected state of the biological marker; and provide a notification for indicating the missed dose of the medication if it is determined that the user has missed the dose of the medication. <EOS>