Once in the blood Anavar becomes active very quickly, as is common with most oral steroids, especially those of a DHT nature. Further, this rapid activity time is largely due to its very short half-life which is approximately 9 hours. Because the half-life of Anavar is so short daily administration of the medication is necessarily frequent with twice daily ingestion of the medication being optimal. You could easily administer the medication only once per day and still receive the benefits of Anavar , however, if we are to keep blood levels stable twice per day will be more efficient as once per day administration would result in very little of the medication still being active in the body once a 24 hour period has passed. Granted, for lower end doses, especially for females once per day will prove to be sufficient.