20mg a day for three weeks is gonna get you nowhere bro. If your gonna do it up the dosage and do it for 4-5 weeks to get anything out of it. But my sugestion would be to not take it at all. Save it until you get some test and then use it in your cycle. What are your stats man? What you can expect after the cycle will be to lose alot of what you gained which pry won't be much considering the low dosage and duration.