
Originally Posted by
Youthful55guy
I Couldn't agree with this more! There's a little known interaction between SHBG and Total T that most people (including many docs) are unaware. It's very important to know your SHBG levels and your Free T (or bioavailable T) to interpret results and make course corrections. You should always base decisions on Free T and never Total T.
SHBG serves the purpose of binding to T and protecting it from liver metabolism. So, the higher your SHBG, the higher will be your Total T with a given dose of TRT. That does not mean you will feel better with that higher level of Total T because SHBG also prevents the T from crossing the blood-brain barrier where T is needed to "feel good".
Here are some real world examples of T/SHBG/Free T labs. I've got many labs results from many different lab over the past 5 years, but I'm only pulling data from a single lab (Lab Corp) so that there are no lab to lab differences to confound the data.
Injection dose = 0.2 mL of a compounded blended 180/20 mg/mL T-cyp/T-prop injected every 3 days (E3D).
Total T--Free T--SHBG--Winstrol
1158-------15-------73------None
831---------27------20------15 mg/day
825---------22------21-------12 mg/day
809---------17------23-------12 mg/day
633---------21------27-------10 mg/day
Ranges: TT 348-1197 ng/dL, FT 7.2-24 pg/mL, SHBG 19.3-76.4 nmol/L
Bottom line is that it's clear that the highest Total T level (from the same dose of T) resulted from the lab where my SHBG was the highest, but that also resulted in the lowest Free T measurement. Then I started manipulating SHBG with Winstrol but maintained the same injection dose of T and saw my Total T drop, but my Free T increase.