Why is transdermal administration of prohormones superior to oral administration?
There are numerous reasons why transdermal delivery can be preferable. The first is that transdermal delivery allows prohormones to avoid first pass metabolism in the liver. Most prohormones are readily destroyed in the digestive tract and liver, often making the dosages required (and money spent) much higher compared to transdermal delivery. It is estimated that transdermal prohormones have a 30-40% absorption rate, compared to 5-15% for oral prohormones. Also, certain hormonal substances may be toxic to the liver, and transdermal delivery significantly lessens this. Secondly, orally delivered prohormones have very short half-lives and must be taken 3-4 times daily. Not only is this inconvenient, but it means that during certain periods (such as sleep) blood levels of the hormone will be very low. Transdermal delivery effectively leads to a steady release over 12 or more hours, solving both of these problems.