T formulation, the dose of T, genetics (polymorphism of the AR), age all play a role in the impact a trt protocol will have on blood markers (RBCs/hemoglobin/hematocrit).
Other factors such as sleep apnea, smoking can have a negative impact on hematocrit.
Injectable T has been shown to have a greater impact on increasing HCT compared to transdermal T.
3–18% with transdermal administration and up to 44% with injection.
In most cases when using injectable T high supra-physiological peaks post-injection and overall T levels (running too high TT/FT level) will have a big impact on increasing HCT.
Manipulating injection frequency by injecting more frequently using lower doses of T resulting in minimizing the peak--->trough and maintaining more stable levels may lessen the impact on HCT but it is not a given.
As again running very high TT/FT levels will have a stronger impact on driving up HCT.
Although injectables have been shown to have a greater impact on HCT you can see even when using a transdermal formulation that maintains stable serum concentrations that the impact it has on HCT is DEPENDANT ON THE DOSE AND SERUM LEVEL OF T.
Using higher doses of transdermal T and achieving higher TT/FT levels will have a great impact on HCT levels.
How high an FT level you are running is critical.
It is a given that most men on trt struggling with elevated RBCs/hemoglobin/hematocrit are running too high an FT level.
Sure some men are more sensitive than others as they may still struggle with elevated blood markers when running lower T levels but it is far from common and many may already have an underlying health issue contributing to such.
If you are struggling with such blood markers then in most cases finding the lowest FT level you can run while still maintaining the beneficial effects may very well be the solution.
Easier said than done as many men on trt tend to do better running higher-end FT levels within reason.
Mind you some are lucky and never have an issue or levels tend to stabilize over time.
Others will continue to struggle until the cows come home.
Unfortunately too many are caught up in running absurdly high trough FT levels due to the herd mentality spewed on the bro forums and gootube!
Other options would be hCG monotherapy (achieve physiological T levels), Natesto (short-lived peaks (800ng/dL)/long trough time between doses), T patch (most closely mimics natural 24hr circadian rhythm/mid-range T levels), Jatenzo (short-lived peaks/longer trough time between doses/achieve physiological T levels).
Some men may even try low dose T <100 mg/week with ND.
Testosterone is the primary sex hormone and anabolic steroid in males.
ND or OXO to replace T.....definitely would not recommend as testosterones metabolites estradiol/DHT are needed in healthy amounts to experience the full spectrum of beneficial effects.
*Natural testosterone is viewed as the best androgen for substitution in hypogonadal men. The reason behind the selection is that testosterone can be converted to DHT and E2, thus developing the full spectrum of testosterone activities in long-term substitution.
