In pawing through muscle mags, I don't often do double-takes when perusing the latest supplement advertisements that constitute greater volume of the magazine than do articles. However, this time - lab work used in an advertisement piqued my interest. There is a current product on the market that uses apparently before and after Growth Hormone (GH) levels with complete disregard for what it is that they are measuring.
A simple GH measurement is NOT a reliable test for establishing serum estimates of excess or deficiency. GH is secreted from the pituitary in PULSATILE fashion (some is squirted here, a little is squirted there, and so on...), so hormone levels FLUCTUATE GREATLY! Even a level of zero could be normal.
In the ad, the two samples weren't even measured at the same time of day (almost 3 hours apart) which is a complete and utter no, no when evaluating repeat lab tests of the endocrine plight. Please don't fall for this! IGF-1 levels might have been more "interesting" in the aforementioned ad setting if drawn also at the same time of day and under the same conditions (fasting, post-workout, et al...), HOWEVER, this is not to suggest IGF-1 isn't without flaws because we really have a hard time understanding what a normal range is.
Phew...happy to get this off of my chest.