You guys realize that half life is cumulative right? So on a 3rd shot of EOD injection, it's 100% of the 3rd shot, 50% of the second shot, 25% of the first shot in the system at that moment of time, that first shots potency isn't "gone". That's why it takes a full 30 days to realize a protocols effectiveness and get an accurate reading of bloods. And it takes a full year for Testosterone to virilize for men on TRT. The more frequent the shots, the sooner the possibilty of the drug virilizing.
And back to low natural original Test readings having nothing to do with low bloods after starting a cycle. There are 3 ways to have low readings after beginning a cycle. 1. Low potency AAS 2. Some men are hyper metabolizers of drugs and may require TRT doses in the range of 225-300 mg per week just to get a reading above 700 and 3. And some are Hyperexcreters (into the urine) and the only way to verify is by evaluation of a 24 hour urine panel, such as one from Rhein Consulting Laboratories.