Heal Yourself At Home


Sex Hormone-Binding Carrier Proteins


   Sex Hormone Binding Globulin (SHBG)

   Corticosteroid Binding Globulin (CBG)


SHBG (sex hormone binding globulin)

Aka. TeBG (TESTOSTERONE-estrogen Binding Globulin)


      SHBG binds to estrogen and TESTOSTERONE in the blood  (making them less bioavailable)


-       Bioavailability of ESTRADIOL or TESTOSTERONE is determined by the level of SHBG - ESTRADIOL and TESTOSTERONE travel in the blood either strongly (but reversibly) bound to SHBG (ESTRADIOL 40%) or loosely bound to serum albumin (ESTRADIOL 59%).  E.g. Only about 1-2% of circulating ESTRADIOL is “free” to enter a cell and activate its receptor.



      SBGH level is delicately balanced by enhancing and inhibiting factors:


-       SHBG is  increased by:      (makes otherwise unbound hormones LESS bioavailable)


         Liver disease, alcohol


         Hyperthyroidism - high levels of thyroxine (T3)




         High levels of estrogen - E.g. use of HRT, oral contraceptives (metabolized by liver);


         High levels of GROWTH HORMONE



-       SHBG is reduced by:           (makes otherwise bound hormones MORE bioavailable)


         Higher circulating INSULIN levels – (note however, that recent evidence reveals that liver’s fat production reduces SHBG, and not any direct effect of INSULIN);


         Obesity - obesity leads to high insulin levels, which causes a reduction in the liver’s production  and circulating levels of SHBG (see note above); note that obesity also increases estrogen production in adipose cells via the aromatase enzyme; Thus, obesity can promote cancers such as breast and endometrial cancer – as estrogen becomes more bioavailable (free/unbound to SHBG) for its target tissues.






         Corticosteroid-binding globulin (CBG)




         Cushing’s disease;


         Soy - up to 10% reduction;


         Nettle root - contains compounds that bind to SHBG; nettle root is also anti-aromatase and therefore acts against estrogen production. 



      High/Low SHBG Conditions


-       Low SHBG (making hormones MORE bioavailable)  - seen in polycystic ovary syndrome, diabetes, hypothyroidism.


-       High SHBG (making hormones LESS bioavailable) - seen in pregnancy, hyperthyroidism, anorexia nervosa. Recent research links high SHBG levels with breast and testicular cancer.



      SHBG production sites


-       SHBG is produced mainly in the liver cells and released into the bloodstream - other production sites are the brain, uterus, placenta and testes (where it is sometimes called androgen-binding protein).



CBG (Corticosteroid-binding Globulin)


      CBG (a.k.a. transcortin) binds to PROGESTERONE, CORTISOL (and other corticosteroids) in the blood


-       Bioavailability of PROGESTERONE, CORTISOL  (and other corticosteroids) is determined by level of CBG


-       PROGESTERONE is bound by CBG (~18%), albumin (~80%), SHBG (0.6%) and ~2% exists in the free state

Clinical Reproductive medicine and surgery, 2007



      CBG level is balanced by enhancing and inhibiting factors:


-       CBG is   increased by:      (makes otherwise unbound hormones LESS bioavailable)


         Estrogens / Pregnancy



-       CBG is reduced by:           (makes otherwise bound hormones MORE bioavailable)


         Cirrhosis (chronic liver disease);




      CBG production


-       CBG is produced by the liver

Hormones Links


HORMONES- Related Links:


Hormones 101 – “Feel Good, Look Good”

Chart of Human Hormones

Testing Hormone Levels

 > Take Hormone Test

 Synthetic Hormones

        – “Frankenstein Version of Natural Hormones”

Balance Adrenal "Stress Managment" Glands  


5-HTP – “SSRI Alternative”

SEROTONIN – “Mood Hormone”

MELATONIN – “Darkness Hormone”

 > The Biological Clock

T3 and T4  - “Thyroid Hormones (Triiodothyronine and Thyroxine)”

HISTAMINE – “Inflammatory Response Hormone”

Fight or Flight Catecholamines:


DOPAMINE –  “Go Get it! /Reward Hormone” 


Low Dose Naltrexone (LDN)  - “For auto immune disease, cancer, AIDS, COPD and the common cold”

FSH, LH and GnRH

PROLACTIN – “Cool Down Hormone”

INSULIN – “Blood Sugar Uptake”,  GLUCAGON, IGF

LEPTIN – “Curb appetite / Burn Fat”

GHRELIN – “Hunger Hormone”


Steroid Hormones

Steroid enzymes affecting Steroid Production /Activity 


 CORTISOL – “Stress Hormone”


ALDOSTERONE – “Water Retentive Hormone”

Sex Steroid Hormones

Sex Steroid Hormones

Sex hormone-binding carriers

Estrogens – “Predominantly Female Sex Hormones”



PROGESTERONE – “Precursor to Androgens, Estrogens and Corticoids”

Estrogens and PROGESTERONE in Lifestage Events

Androgens -"Predominately Males Sex Hormone"


Vitamin D - The Sunshine Vitamin

  CALCITRIOL (active form)

  CALCIDIOL (circulating form)