Sripada et al. reported that oral pregnenolone is preferentially metabolized into the neurosteroid allopregnanolone rather than into other steroids such as DHEA or cortisol .  In further research by their group, a single 400 mg dose of oral pregnenolone at 3 hours post-administration was found to result in a 3-fold elevation in serum levels of pregnenolone and a 7-fold increase in allopregnanolone levels.  Pregnanolone levels increased by approximately 60% while DHEA levels decreased non-significantly by approximately 5% and cortisol levels were not affected.  Another study found that allopregnanolone levels were increased by 3-fold at 2 hours post-administration following a single 400 mg oral dose of pregnenolone. 
Renal parenchymal disease can be a cause or consequence of hypertension. Progressive renal damage is caused by the mechanical and humoral effects of glomerular hypertension. The renal damage decreases the kidneys' ability to excrete salt and excess fluid (resulting in a low renin state, as opposed to the high renin state found in renovascular hypertension), and the hypertension worsens. As renal damage progresses, hyperparathyroidism develops and erythropoietin production increases, exacerbating the hypertension. 5 , 18 Thus, a vicious cycle of worsening renal function and hypertension begins.
Transdermal patches (adhesive patches placed on the skin) may also be used to deliver a steady dose through the skin and into the bloodstream. Testosterone-containing creams and gels that are applied daily to the skin are also available, but absorption is inefficient (roughly 10%, varying between individuals) and these treatments tend to be more expensive. Individuals who are especially physically active and/or bathe often may not be good candidates, since the medication can be washed off and may take up to six hours to be fully absorbed. There is also the risk that an intimate partner or child may come in contact with the application site and inadvertently dose himself or herself; children and women are highly sensitive to testosterone and can suffer unintended masculinization and health effects, even from small doses. Injection is the most common method used by individuals administering AAS for non-medical purposes.