I know what all the sites claim the various half lives of the different esters are. I subscribe to a different interpretation. I have mentioned this before. Sadly, I cannot provide an empirical link to back up this viewpoint.
I have long held to the notion that if you take the number of carbon atoms in an ester and multiply this by a factor of .7 you get your functional half life.
Tren Ace, 2 carbons = 1.4 day half life. This is the reason Ace is so much better as an ED than an EOD; those who have tried it both ways will testify.
Test Prop, 3 carbons = 2.1 day half life. Everyone knows to hit Prop EOD.
Nandrolone Deca, 10 carbons = 7 day half life. This is why you can justifiably pin Deca just once a week.
The interesting ones are the big two enanthate and cypionate. 7 and 8 carbons respectively, 4.9-5.6 days respecitvely. This is why E3D or twice a week work so well for Enan and Cyp. Lots of TRT protocol calls for weekly Cyp injections. From the chart you can see you can almost get away with it. My very first Test cycle, I used Cyp and I hit it just once a week. Because in part I too read the notes Cortes sited above that Cyp’s half life was 12 days or so. If that were the case once a week would have been fine. My results were decent. However, then I stumbled across this info about the .7 factor. My next Test Cycle I do hit it twice a week and that was a much better Test Cyp experience for me than just once a week.
Bottom Line you can always inject more frequently than called for. You can hit Cyp and Deca ED if you want. If you don’t then I believe the .7 factor protocol is the best way to fly.