This is the nugget of truth from the video. Different sites may differ in at least three important ways that will influence outcomes:
1) Absorption of testosterone
2) Amount of 5-alpha reductase enzyme
3) Amount of aromatase enzyme
So for the same amount of testosterone cream applied to any particular site, you may have a different testosterone level, a different DHT level, and a different E2 level. I've been discussing this with [USER=40995]@Jerajera[/USER] quite a bit recently and his personal results have been very different from Cortex's observations.
Jerajera had relatively low T and high DHT and E2 with scrotal application, and higher T and lower DHT and E2 with inner arm / inner elbow application (still biased towards a higher DHT/E2 ratio than injections though). I found one study which suggests scrotal skin has an amount of aromatase comparable to adipose tissue. The focus is usually on the increased DHT conversion with scrotal application, but it may be that scrotal skin also produces less desirable T/E2 ratios in some people.
