According to a study of medical doctors from Iowa City, the range of detectability times starts with as little as a few days and can go as far as 18 months after the last use of the substance, depending on various factors.

A urine test will detect steroids in a urine sample for up to 28 days. The detection window will vary depending on various factors, like the quantity of steroids consumed and the metabolism of the person tested. Blood Test: Within 14 Days

Evidence of steroids can linger in your body for considerably longer than its half life would suggest, and it’s the processes which cause the steroid to remain detectable long after you’ve stopped using it that you need to be aware of.

To avoid detection of steroids in their urine, athletes will stop using the drugs well before the competition. Yet, in many cases, steroids can still be detected long after the athlete stops using them (even weeks later!).