Replacement dose is 80-150mg/wk for the most part. There are some variability between individuals. Levels best regulated with lower dose shot once/wk or even split twice weekly but usually not necessary. Even every other week makes little sense based on half life of T. Go to a doctor trained in this if you are 40 and up, there are things to watch and ways to keep risks minimal (less than most other prescriptions). Most studies say there is a null effect on cardiovascular health, several show lower CVD risk (again this is medically monitored). Only 2 studies showed a small risk but they used androgel and poor quality retrospective studies. The one study was a VA study and subjects were old with lots of medical problems and androgel not very well regulated with subjects. Very low testosterone and very high testosterone have both been shown to increase cardiovascular risk. Don't risk going the illegal route, too much bad stuff out there, plus you have piece of mind your staying healthy and legal. As you get older its most important to stay healthy.
400mg/wk is definitely not medical dosing.