Measuring 5-AR activity

Anyone tried these tests?

The way to use serum labs to monitor 5-AR activity, and thus DHT metabolism, is to look for the classic case of high-T with high-E2 with low-SHBG.

But if this situation is not self-evident, then we must switch to 24 hr urinary anlaysis.

24hr Rheins urine analysis provides measurements of THF (tetrahydrocortisol) and 5a-THF (allo-tetrahydrocortisol), and the ratio of 5a-THF to THF ( ie: 5a-THF / THF ) follows the 5alpha reductase activity, ie:

high ( 5a-THF / THF > 1.3 ) shows high 5 alpha reductase activity (above 90 percentile)

mid ( 5a-THF / THF = 0.8 ) shows average 5 alpha reductase activity

low ( 5a-THF / THF < 0.6) shows low 5 alpha reductase activity (below 10 percentile)

Taken together, these are good indicators of 5 alpha reductase acitivity, and thus DHT metabolism. Dr Crisler seems to agree.

musclechatroom.com/forum/…4&postcount=23

…and the physiological ranges have been determined by Dr Jonathan Wright (Meridian Valley Labs) here:
meridianvalleylab.com/news-fall2004.html

…with the minim and average values taken directly from Meridian Valley Lab’s paper report , ie: there is no URL link available at this stage, per CowboyBob’s posts here:
part 1: musclechatroom.com/forum/show…7&postcount=10
part 2: musclechatroom.com/forum/show…6&postcount=12

…and there are many research papers which use the same urinary metabolite markers to demonstrate 5 alpha reductase activity, and DHT metabolic activity, eg:

“Diagnosis of 5alpha-reductase 2 deficiency: a local experience”
hkmj.org/article_pdfs/hkm0904p130.pdf

musclechatroom.com/forum/showthread.php?4634-Monitoring-DHT-metabolism-and-5-alpha-reductase-activity&p=57536#post57536

vincentv, there are a couple of key threads on this subject, here is one of the oldest:

viewtopic.php?f=4&t=761

Also see Oscar’s related thread that includes testing of some of these metabolites in serum.