SHBG - what affects the level?

I recently had bloodwork done to test estrogen and thyroid levels and endocrinologist added SHBG test. She is trying to find out why I seem to need more estrogen and feel better when levels are much higher than the norm. I have an appt with her next week to go over results but got a copy of test results and SHBG was flagged as HIGH (esp for non-pregnant females).

Just wondered if anyone out there had theirs test high and what dr says this is due to.

Very high estrogen levels and hyperthyroidism are two causes that I know of.

My here....
SHBG carries sex hormones. Estrogen replacement therapy can raise the SHBG level especially when using oral ERT or using too much of any form of estrogen.
The body carries sex hormones three ways....free form, weakly bound to albumin, or to bound to SHBG.

Something I learned was...High SHGB can be linked to low libido. SHBG goes around binding up the excess estrogen and at the same time binds up the free testosterone. The body doesn't distinguish between the molecules.

You feel better with more estrogen so maybe a higher SHBG is okay.... for you....?

Progesterone levels must also play into this as well. Not sure how. I would think if the P level is high it would also raise the SHBG.

Hi Calypso, I wish I had an intelligent answer for you because I want you to feel good. You help so many women on here.
The only thing I remember about SHBG is that it can be elevated in women taking hormone contraceptive. So there must be a hormone connection for us women on HRT.

Saw my endocrinologist today. My estrogen was over 400 when recently tested, TSH very low, T3 and T4 within acceptable levels. I use Armour thyroid.

I asked about the SHBG and what affects it. She said that taking thyroid meds, esp T3 will elevate SHBG and therefore less of the estrogen will be unbound. She is not concerned with my estrogen level being above 400 since my SHBG is flagged high. She said by lowering my thyroid meds (not yet, but in the future), that will lower SHBG and then would be able to decrease estrogen dose. She said using 200mg prometrium every few nights is fine (100mg other nights) but she'd be fine with upping to 200mg prometrium nightly (especially for preventing endo regrowth).

Interesting dr visit. I was worried about my estrogen level being too high. As she said, a lot of that 400 is probably unavailable for use. If there were a FREE ESTROGEN test, that would give more info but there is not one at present.

Glad you had a good visit.

There is a free estradiol test. It is an uncommon test and you can check with your lab if they do it. They may have to send it out to another lab but it can be done. It may give you another clue to whats going on.

My belief is if one hormone is too high (or too low) it throws off everything else making other hormones ineffective.

I know your doc is probably right, this hormone stuff is way over my head, but this was in the Vliet book. Screaming To Be Heard, says that estradiol is tied up by SHBG and thyroid is tied up by thyriod-binding globulin (TBG). It also says that "the free amount of all the hormones is a much less percentage than the total circulating hormone." (pg 38)