T Nation

Low SHBG Question


Hi all

Quick question for you guys: If someone has low SHBG (<12 nmol/ml), does that mean that the 'preferred' normal E2 value of 22 nmol/ml could be too high since E2 also binds to SHBG? I mean, does it work the same way it do with T, and this makes more free E2 circulating?

I'm asking because my SHBG is always between 10 and 12... and I've been struggling with high E2 symptoms even if I take .5 Arimidex EOD and get my E2 near 22 nmol/ml.

BTW, I'm not on T injections, only HcG monotherapy at 500iu EOD with 0.5mg anastrozole pill EOD. Haven't succeeded yet in convincing my Endo to give me a T cyp script...

Anyways, this got my Free T at 500 pmol/L (223-915pmol/L) but I'm clearly not feeling better and still has all the symptoms of Low T and High E2 (metabolic syndrome, fatigue, gyno, brainfog, etc.)... so I was wondering if my low SHBG could have something to do with this.

Any idea?
Thanks in advance! :slightly_smiling:


SHBG does not circulate T, because it binds tightly and will not release any T to tissues in the body. Estrogens bind less tightly and SHBG-E can release estrogens to tissues. Many get this estrogen concept transport concept mixed up in terms of thinking that the same is true for testosterone. Bio-T is a one way transport to the liver for clearance.

A lot of T is weakly bound to other proteins, mostly albumin. This fraction and FT are bio available T, or bio-T. Note that this correctly infers that SHBG-T is not bio-available.

With less GHBG, there will be proportionately more free E2, but I do not know what the implications of that are.

You can try lowering E2 and see how that works for you. This is uncharted territory. It would be good to have FT lab data.

Do you have DHEA-S data? What are your cholesterol levels? With your climate, it would be easy to be vit-D3 deficient.


have you checked out your TSH and cortisol numbers as well?


I'd get some testosterone and get your levels above 800 before you do anything. HCG mono therapy is stupid. I don't know why you are taking anastrozole and not testosterone and your doctor probably doesn't know either.


Elevated E2 causes symptoms, ever when T levels are high. And elevated E2 lowers T levels. If the OP is younger, there might be some good reasons for this.


Thanks for the info on SHBG and E2 KSman!

Now regarding why I'm on this protocol, KSman said exactly what my Endo said... she wanted to give this a try since I'm 32. We tried HcG alone for a few months and my E2 went through the roof so she prescribed Arimidex 0.5 EOD.

Here are my latest labs results after 3 months of HcG and Arimidex :

SHBG = 10 nmol/L (12-46) (LOW)
Testosterone (Total) = 14.7 nmol/L (10-30)
Free Testosterone = 545 pmol/L (223-915)
FSH = 03 UI/L (1.4-18.1) (LOW)
LH = 0.1 UI/L (1.5-9.3)(LOW)
E2 = 24 pmol/L (No reference value)
DHEA-SO4 = 7.9 umol/L (1.4-12.5)
Prolactin = 8.2ug/L (2-18)
Progesterone = 4.34 nmol/L (0.9-3.9) (HIGH)
Cortisol (S) = 505 nmol/L (No reference)
TSH = 4.13 mUI/L (0.35-5.50)
Free t3 = 6.9 pmol/L (3.5-6) (HIGH)
Free t4 = 15.1 pmol/L (10-23)
25(OH) = Vit. D 95 nmol/L (no reference)

I'm wonderin if HcG works as intended since we tried 250, 500 and even 1000ui EOD, and it never increased my T above 15 nmol/L (440 ng/dl).

I don't have recent Cholesterol values but I never had any problems on that side.


Low SHBG is what you want -Less opportunity for binding with estrogen. HCG is not enough. Good luck - I'd recommend finding a new doctor that doesn't substitute HCG for test therapy.


High dose hCG has a reputation for high E2 levels, which can be resistant to management with an AI. If 250 - 500iu SC EOD does not work, accept that. Higher doses can harm the LH receptors and may things worse!!


Your E2 is way too low. I would have expected 0.5mg/week for adex to get you near E2=22pg/ml given your T levels, 0.15mg EOD [5.25 mg/week calculated ] based on your labs. Are you experiencing any joint aches or pains?

Low E2 is often associated with diabetes and insulin resistance. Got fasting serum glucose data?

Low E2 can also lower SHBG.

Low E2 can kill libido. Low E2 can have some symptoms in common with elevated E2.

If hCG does not get the job done, LH created by a SERM might not work either. No harm trying. Again, you do not want to use large doses because high LH levels can create the same problems.

Really low estrogen levels can create high cholesterol problems, as some body builders have demonstrated.


Oops, I made a typo here : my E2 is 84 pmol/L, not 24 pmol/L. So it is actually not bad at all.
Good to hear the cons of lowering it too much though... I'll think twice before upping my arimidex dose.

On a totally unrelated topic (or not...), I just got my test results from RLA ELISA/ACT. It appears that I'm allergic to quite a few things that I'm eating (or exposed to) every day, making me in a constant inflammatory state. Might be related to the fatigue I'm experiencing. I'll be starting an elimination Diet to see if things gets better (with the V-Diet as a base).