Sex Hormone Binding Globulin and Free Testosterone—Your Normal Results May be Wrong

Are you experiencing the symptoms of low testosterone despite lab results that show a healthy total testosterone level?

You’re not alone. Men are often told that their levels are perfectly normal, yet they don’t feel well.

The truth is that diagnosing and confirming low testosterone is a complicated endeavor. It requires thorough lab testing and careful interpretation of the results. Many medical professionals fail to consider the effects of sex hormone binding globulin (SHBG) on your hormone balance and the importance of measuring bioavailable free testosterone levels.

A medical researcher uses a microscope to look at the chemical composition of sex hormone binding globulin.

More Sex Hormone Binding Globulin Means Less Free Testosterone

Sex hormone binding globulin (SHBG) is a protein produced by the liver (along with albumin) that binds to your sex hormones, including testosterone, DHT (dihydrotestosterone), and estradiol (an estrogen that is necessary for male hormone balance).

It renders testosterone molecules inert—unable to perform their crucial role.

45% to 65% of testosterone in men’s blood is bound to SHBG. Only about 2% to 3% of testosterone is immediately available as free testosterone to be utilized by the body’s tissues.

In other words, SHBG levels can affect the amount of hormone available to power many of your body’s critical systems. Higher levels of SHBG mean lower levels of usable testosterone.

Your body may be producing sufficient, healthy amounts of testosterone (revealed by a total testosterone reading) but unable to use enough of the hormone produced to function at the level it should.

(If you’re interested in the numerical total and free testosterone levels considered to be normal for your age group, read the Endocrine Society Clinical Practice Guideline here.)

How SHBG and Free Testosterone Affect Your Wellbeing

If the amount of bioavailable or free testosterone is too low, you may develop the symptoms of hypogonadism (the medical term for Low T), including:

  • Low libido (sex drive)
  • Erectile difficulty
  • Fatigue
  • Weight control problems
  • Concentration and memory deficits
  • Anxiety
  • Depressed mood
  • Weakened bone structure (osteoporosis)
  • Possible pulmonary issues

Men who are told their levels are normal yet experience symptoms may be in a situation where their free testosterone levels have not been measured correctly, and the role of sex hormone binding globulin (SHBG) has not been assessed properly.

If you have too much SHBG, what is considered a healthy total testosterone level for others could be insufficient for your body. You actually may have low testosterone because your free testosterone levels are too low.

The Good News About Testosterone Replacement Therapy

Whether you’re experiencing symptomatic, clinical hypogonadism due to insufficient production of testosterone or due to high levels of SHBG reducing your free testosterone, it’s important to realize:

  • You’re not just getting old
  • Your debilitating symptoms are not normal
  • You don’t have to live with your symptoms

Low T is treatable.

The most effective way to restore and then maintain healthy testosterone levels for men who are chronically deficient (regardless of the root cause) is Testosterone Replacement Therapy (TRT).

This treatment has improved the quality of life of a growing multitude of men worldwide. With a little help from our team of professionals, you can enjoy life again, and you can rest assured that we’ll take good care of you, every step of the way.

Your initial consultation is free.

Book a Free Consult


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(Augie) Juan Augustine Galindo Jr. MPAS, PA-C

(Augie) Juan Augustine Galindo Jr. MPAS, PA-C started his career in healthcare as a fireman/paramedic in West Texas where he served on the Midland Fire Department from 1998-2004.   He became interested in testosterone treatment after seeing how hormone replacement doctors helped those suffering from low testosterone.   After graduating from the Texas Tech Health Sciences Center Physician Assistant Program, he moved to DFW where he currently lives with his wife and three children.


  1. Ed Nasser on 12/01/2020 at 11:26 am

    excellent article. High SHBG was a major problem for me, along with high prolactin levels. I find your writing very helpful

  2. Frank on 01/28/2021 at 11:52 am

    My question: I am a healthy 62 year old male on no meds . I have been on TRT for over 15 years. Usage ranged from weekly to bi weekly to every other day injections to creams. I have used compounding pharm test etc. I had to stop taking the test about a year ago do to the serve side effects I was getting. In addition to that I was DX with leaky gut and with that I don’t have the ability’s to take and supplements etc. I have seen many doctors in regards to my food and test issues over the past year and nonene has been able to figure out my body.
    I am looking for a functional Dr who can get to the bottom of what is going on with body on the cellular level and correct my issues.
    my office number is 856.439.9165. Home base is NJ.

    • Hello Frank!

      With experience and planning, the side effects of TRT are typically managed easily. I fully support functional medicine and think you are on a good track there. As for TRT, I believe injections are the best current methodology for replacement. We can offer telemedicine consultations if that interests you, but as of yet, we are unable to treat out-of-state patients. I wish you the best of luck in finding the root cause issues.

      Best regards,
      Augie Galindo MPAS, PA-C
      Testosterone Centers of Texas | Managing Partner

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