What is Sex Hormone-Binding Globulin (SHBG) & why it is so important?
Sex Hormone-Binding Globulin (SHBG) is a protein made in the liver and is then released into the blood stream. The purpose of SHBG is to determine how much testosterone stays attached to it in the bloodstream versus what goes into the cells. Think of SHBG as the body's testosterone regulator. Inactive testosterone stays bound to SHBG. When the cells need more testosterone, SHBG will release testosterone into the bloodstream as free testosterone to be able to go inside the cells becoming active where the true benefits of testosterone occurs.
What causes elevated SHBG levels?
Causes of increased SHBG levels are typically lifestyle based. The most common cause is age. Alcohol use, chronic acetaminophen use, hyperthyroidism (increased thyroid function), HIV, and liver disease are also causes. Keto and low carb diets will increase SHBG levels, as well.
If SHBG is a little high, testosterone injections will naturally reduce it. As it comes down, it will release more free testosterone while raising your total testosterone. Also, correcting the causes mentioned above will also help to decrease an elevated SHBG level.
What causes decreased SHBG levels?
Causes of decreased SHBG levels are diabetes, insulin resistance (metabolic syndrome), steroid abuse such as oral anabolics, and hypothyroidism (decreased thyroid function). Also, injecting too much testosterone at once. This is why "cookie-cutter" testosterone replacement therapy protocols do not work.
If SHBG is too low, this means the frequency of your injections of testosterone will need to change and will also determine how much you are injecting to keep it from dropping even more. The goal is to have SHBG come back up, but it will take time. This can take several months.
How you can naturally raise SHBG is through consuming good fats in your diet such as nuts, extra virgin olive oil, avocado, and salmon.
In summary, SHBG not only determines how frequently you must inject your testosterone, but also how much you should inject when you do so. When SHBG falls too low, this is when signs of high testosterone levels will present because SHBG is not holding enough testosterone in your bloodstream. So, now your cells are getting over-saturated with free testosterone. Signs of high testosterone include anger/aggression aka "roid rage", anxiety, insomnia, a racing heartbeat, flushing of the skin, heart palpitations, and high blood pressure. SHBG can be measured with a simple blood test by drawing your blood at a local lab.
If you are currently taking testosterone replacement and your health care provider is not checking your SHBG levels, you need a new provider as you can see how important it is!
