What's The Function Of SHBG?

[TheBeard]

I keep reading on steroid forums and bodybuilding websites that low SHBG is the key as it frees up more hormones to be available for the receptors.

But I remember that I felt a lot more horny when my SHBG was normal/high and my free T was low, than now that my SHBG is low and my free T is above normal range. I was also putting on more muscle.

@haidut what's up with SHBG? What is its function? Does it act as a transporter and would actually be better off high-ish?

I am not buying the rationale that it has to be low, if it's manufactured by the body I'm sure it has its place

 

[ecstatichamster]

Dr. Peat says that it helps testosterone and androgens enter the cells. So it should be higher not lower.

 

[TheBeard]

Dr. Peat says that it helps testosterone and androgens enter the cells. So it should be higher not lower.

Exactly my intuition too when I see how un-androgenic I feel and look when my SHBG is low.

The issue is I feel very good on exemestane, but it lowers SHBG.

How to raise SHBG? (other than coffee)


I have very low SHBG and IGF-1, so my other intuition is that my liver function is quite compromised.
Don’t know how to improve this either, no amount of NAC or milk thistle improves it

 

[Spondive]

Exactly my intuition too when I see how un-androgenic I feel and look when my SHBG is low.

The issue is I feel very good on exemestane, but it lowers SHBG.

How to raise SHBG? (other than coffee)


I have very low SHBG and IGF-1, so my other intuition is that my liver function is quite compromised.
Don’t know how to improve this either, no amount of NAC or milk thistle improves it

I would try alpha tocopherol succinate 800 iu day and 2-4 mg of copper sulfate or gluconate per day.

A role for low hepatic copper concentrations in nonalcoholic Fatty liver disease. - PubMed - NCBI

 

[BigChad]

Dr. Peat says that it helps testosterone and androgens enter the cells. So it should be higher not lower.

Exactly my intuition too when I see how un-androgenic I feel and look when my SHBG is low.

The issue is I feel very good on exemestane, but it lowers SHBG.

How to raise SHBG? (other than coffee)


I have very low SHBG and IGF-1, so my other intuition is that my liver function is quite compromised.
Don’t know how to improve this either, no amount of NAC or milk thistle improves it

Hyperthyroidism raises shbg as does caffeine.
But if low shbg is a bad thing, this is concerning cuz things that lower shbg include vitamin d, calcium, magnesium, zinc, boron, fish oil, high protein diets.

 

[BigChad]

Should we be avoiding supplements of those things and high protein diets then. I assums high protein means 1g per pound bodyweight

 

[Shin]

Exactly my intuition too when I see how un-androgenic I feel and look when my SHBG is low.

The issue is I feel very good on exemestane, but it lowers SHBG.

How to raise SHBG? (other than coffee)


I have very low SHBG and IGF-1, so my other intuition is that my liver function is quite compromised.
Don’t know how to improve this either, no amount of NAC or milk thistle improves it

TUDCA is very good for liver health.
Tauroursodeoxycholic Acid Supplement - Science-based Review on Benefits, Dosage, Side Effects

 

[milkboi]

Hyperthyroidism raises shbg as does caffeine.
But if low shbg is a bad thing, this is concerning cuz things that lower shbg include vitamin d, calcium, magnesium, zinc, boron, fish oil, high protein diets.

The Great Fish Oil Experiment

 

[BigChad]

The Great Fish Oil Experiment

Yes i know boron and fish oil are concerning i just wanted to include everything i knew that lowered shbg. Its weird for zinc mag calcium and boron fish oil to all lower shbg

 

[lampofred]

SHBG is strongly protective against estrogen.

 

[BigChad]

SHBG is strongly protective against estrogen.

Doesnt it preferentially bind to dht and test over estrogen. Plus how come a variety of supplement lower shbg. I guess anything that would increase test or estrogen would lower shbg and that's why zinc, mag, vit d calcium are pro test anti shbg while boron fish oil are pro estrogen anti shbg?

 

[Lokzo]

My SHBG has maxed out, and I'm also very high Thyroid, so I think it's protective against my also very high estrogen

 

[TheBeard]

This article sheds a bit more light on SHBG:

http://www.hormonebalance.org/images/documents/Carruthers 08 TD sxs vs assays JSM.pdf

"SHBG not only regulates the absolute but also the relative amounts of sex steroids available to tissues because it is an “estradiol amplifier” [60], having a fivefold greater affinity for testosterone. This explains why with age, as SHBG levels rise in men, FT levels fall, and as evidence of greater estrogenic action, both benign enlargement of the prostate and gynecomastia become more common conditions. Also, estrogenic feedback on the pituitary gonadal axis inhibits testosterone production by the testes (Figure 2).

Regulation of SHBG Protein Expression
Given the pivotal role of SHBG in regulating the activity of the sex steroids, by sequestering them in the bound state, it is important to recognize the factors that modulate SHBG levels (Table 2).

Cellular Actions of SHBG
In addition to its function as a steroid-binding protein and estrogen amplifier, SHBG also functions as part of a novel steroid-signaling system that is independent of the classical intracellular steroid receptors. Recent research has shown that SHBG is a modular protein, which comprises an N-terminal steroid-binding and dimerization domain, and a C-terminal domain containing a highly conserved consensus sequence for glycosylation that may be required for other biological activities such as cell-surface recognition [61].
Unlike the intracellular steroid receptors that are hormone-activated transcription factors, SHBG mediates androgen and estrogen signaling at the cell membrane via a cyclic adenosine monophosphate (cAMP)-dependent pathway [62] (Figure 3).
That this is a separate pathway of steroid action is shown by the fact that inhibitors of the transcriptional activation of the AR and estrogen receptor do not affect the cAMP response [63].
In the prostate, it has been suggested that the estradiol-activated SHBG/sex hormone binding globulin-receptor (SHBG-R) complex cross-talks with the AR and is able to activate the AR even in the absence of DHT [64]. These factors may be of importance in relation to the actions of androgens and estrogens in the causation and treatment of both benign and malignant prostatic disorders."

 

[Charger]

Does anyone know if SHBG climbs back to baseline after ceasing exemestane?

 

[TheBeard]

Can be brought back up.

With B vitamins especially.

 

[Charger]

Thanks, was actually interested in lowering my SHBG a little to assess how I feel as it's high on my bloodwork. I believe both Fin and Progesterone raise SHBG and this was something I never really looked into lowering afterwards to see what kind of effects it would have.

 

[Coderr]

I guess it's not good to take boron supplements

 

[aadrock]

My SHBG has maxed out, and I'm also very high Thyroid, so I think it's protective against my also very high estrogen

I would assume this means you have high estrogen (only in your blood) due to high testosterone. And the thyroid is doings its job well and keeping the estrogen out of the tissue, and only (mostly) in the blood and eliminating it. Or am I wrong? I assume prolactin would be low in this case, as you would not be in a stressed/high cortisol state.