Short answer: High SHBG in men means the liver is making more sex hormone binding globulin, the protein that grips testosterone and keeps it inactive in the blood. As SHBG rises, less of your total testosterone is free for tissues to use, so a man can have a “normal” total testosterone result and still have low free testosterone. Common causes include older age, hyperthyroidism, liver disease (including cirrhosis), very low body weight or eating disorders, some antiepileptic drugs and low testosterone production itself. The way to lower SHBG is to find and treat that cause with a doctor, not to guess with supplements.
Key Takeaways
- SHBG is a protein made mostly in the liver. Testosterone bound to it cannot act on your tissues.[1]
- In men, about 45% of circulating testosterone is tightly bound to SHBG and only about 1 to 3% is fully unbound.[2]
- Documented causes of high SHBG include liver disease, hyperthyroidism, anorexia or eating disorders, male hypogonadism, antiepileptic drug use and older age.[1][2][3]
- When SHBG is high, total testosterone alone can mislead. Doctors then measure or calculate free testosterone, ideally on morning samples repeated on two days.[5]
- “How to lower SHBG” really means “how to treat what is raising it.” High SHBG calls for a medical workup. No supplement is a treatment for it, and that includes Ultra Bann.
What SHBG Is and Why It Matters for Free Testosterone
Sex hormone binding globulin (SHBG) is a carrier protein produced mainly by the liver. It binds testosterone, dihydrotestosterone (DHT) and estradiol and carries them in an inactive form.[1][2] MedlinePlus puts it plainly: sex hormones bound to proteins such as SHBG “cannot work with your tissues.”[1]
Testosterone in a man’s blood exists in three pools:
- SHBG bound testosterone: tightly held and not available to cells. In men this is roughly 45% of the total.[2]
- Albumin bound testosterone: loosely held and able to break free when tissues need it.
- Free testosterone: the small unbound fraction, about 1 to 3%, that is immediately available.[2]
Free testosterone plus the albumin bound portion is called bioavailable testosterone. When SHBG climbs, more testosterone is locked into the first pool. MedlinePlus explains that high SHBG “likely means that less of your total testosterone is available for your tissues to use.”[1] For a deeper look at how these numbers relate, see our guide to free vs total testosterone.
Why a normal total testosterone can still hide a problem
A standard total testosterone test counts both free and bound hormone, so it “can’t tell your provider how much of your testosterone is free for your body to use.”[1] That is exactly why an SHBG test is ordered: to explain symptoms when the total testosterone number does not fit how a man feels.[1][2]
What Causes High SHBG in Men
SHBG is under positive control of estrogens and thyroid hormones and is suppressed by androgens, according to Labcorp’s test notes.[3] That explains most of the causes below: anything that raises thyroid hormone, increases estrogen exposure, reduces androgen production or disturbs the liver can push SHBG up.
| Cause of high SHBG | Why it matters | Source |
|---|---|---|
| Older age | SHBG tends to rise with age in men. In a pooled dataset of 12,330 men aged 25 to 85, older age was linked to higher SHBG. | [3][4] |
| Hyperthyroidism (overactive thyroid) | Thyroid hormones stimulate SHBG production. | [1][2][3] |
| Liver disease, including cirrhosis | The liver makes SHBG, and liver disease is a recognized cause of high levels. | [1][2][3] |
| Anorexia, eating disorders, very low body weight | Severe under-eating is linked to raised SHBG. Higher BMI is linked to lower SHBG. | [1][2][4] |
| Male hypogonadism (low testosterone production) | Androgens normally suppress SHBG, so low production can let it rise. | [1][3] |
| Antiepileptic (anticonvulsant) drugs | Listed as a cause of increased SHBG; phenytoin and phenobarbitone are named as drugs that affect SHBG. | [2][3] |
| Estrogen use | Estrogen containing medicines raise SHBG (mostly relevant to women, but any estrogen exposure counts). | [1][2] |
| Current smoking | Associated with higher SHBG in the large pooled analysis (an association, not proof of cause). | [4] |
What about body fat and blood sugar?
Many men assume weight gain raises SHBG. The data point the other way. Obesity is listed as a cause of low SHBG, along with hypothyroidism, type 2 diabetes or insulin resistance, Cushing’s syndrome and androgen or anabolic steroid use.[1][2][3] In the 12,330 man dataset, higher BMI went with lower SHBG.[4] So a lean, under-fueled man and an overweight man can both have low free testosterone, but for opposite SHBG reasons.
Alcohol
The large pooled study did not report a link between alcohol intake and SHBG.[4] Heavy drinking matters mainly through the liver: if it leads to liver disease, that disease is a recognized cause of high SHBG.[1][3]
Symptoms: What High SHBG Can Feel Like
High SHBG has no symptoms of its own. What men notice are the effects of lower available testosterone. MedlinePlus lists the symptoms that commonly prompt testing in men:[1]
- Low sex drive
- Difficulty getting an erection
- Fatigue or loss of muscle mass
- Fertility problems
Lab Tests Online UK adds that when SHBG is high, less testosterone reaches the tissues than the total level suggests, which “could lead to poor libido in men.”[2] Symptoms of the underlying cause may also show up: weight loss, heat intolerance or a racing heart with an overactive thyroid, or fatigue and swelling with liver disease. Our article on the signs of low testosterone covers the wider symptom picture.
Testing: SHBG Normal Range for Men and How Results Are Read
The SHBG test is a simple blood draw from a vein in the arm, usually taking less than five minutes, and MedlinePlus says no special preparation is needed.[1] Tell your clinician about every medicine, vitamin and supplement you take, and do not stop any prescription on your own.[1]
SHBG normal range (male)
Reference ranges vary by lab and method. As one example, Labcorp lists these adult male intervals:[3]
| Age | Labcorp SHBG reference interval (male) |
|---|---|
| 20 to 49 years | 16.5 to 55.9 nmol/L |
| Over 49 years | 19.3 to 76.4 nmol/L |
Notice the upper limit is higher for older men, which reflects the age related rise. Always compare your result with the range printed on your own report.
How testosterone should be tested alongside SHBG
- Morning samples: testosterone is best measured between 8 am and 10 am, outside of acute illness.[5]
- Two separate mornings: two measurements are required, because about 30% of men with an initially abnormal level have a normal repeat value.[5]
- Free testosterone when SHBG is altered: if altered SHBG is suspected, free or bioavailable testosterone should be measured, with equilibrium dialysis preferred over commercial direct assays.[5]
- Free androgen index: some labs report total testosterone divided by SHBG. Lab Tests Online UK notes these calculations are not recommended as first line tests.[2]
To see where a total testosterone result sits, read our guide to normal testosterone levels.
How to Lower SHBG: What a Doctor Actually Does
There is no stand-alone “SHBG lowering” treatment. A clinician works backward from the number to the reason:
- Confirm the result. Repeat morning total testosterone with SHBG and a reliable free testosterone measurement.[5]
- Check the thyroid. Thyroid blood tests screen for hyperthyroidism, a classic cause of high SHBG. Treating the thyroid problem addresses the driver.[1][3]
- Check the liver. Liver blood tests and a review of alcohol intake look for liver disease or cirrhosis.[1][3]
- Review medicines. Antiepileptic drugs and estrogen containing products can raise SHBG. Any change must be made by the prescriber, never by the patient alone.[1][2][3]
- Look at nutrition and body weight. Very low body weight and eating disorders are linked to raised SHBG.[1][2] Restoring adequate intake under medical guidance is part of care.
- Evaluate the testes and pituitary. If free testosterone is truly low, the doctor assesses for hypogonadism and discusses whether treatment is appropriate.[3][5]
Stopping smoking is worth doing for many reasons, and smoking is associated with higher SHBG in population data.[4] General habits that support hormone health, such as sleep, adequate protein and resistance training, are covered in our article on how to increase testosterone naturally, but they are not a substitute for diagnosing the cause of a high SHBG result.
A word on supplements sold to “lower SHBG”
Online lists of SHBG lowering supplements are common. None of the sources reviewed for this article recommend a supplement to treat high SHBG, and the documented causes above are medical conditions or medicines that need proper evaluation. Be cautious with products that claim to “free up” testosterone.
Where Ultra Bann Fits (and Where It Does Not)
Ultra Bann is a natural male vitality supplement by DL Bioproducts, taken as one capsule every 2 days. It contains seven botanicals with every amount on the label (Thai Butea superba, Panax ginseng, Cynomorium songaricum, black ginger, tongkat ali, epimedium and reishi, 800 mg in total). It is not a treatment for high SHBG, low testosterone or any medical condition, and it should not replace testing or care from your doctor. If you take it, list it with your other supplements when you get blood work. You can review the full label on our ingredients page or see the product on the shop page.
Frequently Asked Questions
Is high SHBG in men dangerous?
High SHBG itself is a marker, not a disease. What matters is why it is high (for example thyroid or liver disease) and whether it has left you with low free testosterone. Both questions need a clinician and follow up tests.[1][3]
What is a normal SHBG level for a man?
It depends on the lab. Labcorp, for example, lists 16.5 to 55.9 nmol/L for men aged 20 to 49 and 19.3 to 76.4 nmol/L for men over 49.[3] Use the range printed on your own report.
Can high SHBG cause low testosterone symptoms with normal total testosterone?
Yes, that is the main reason the test exists. Because high SHBG leaves less testosterone available to tissues, a man can have symptoms such as low libido even when total testosterone looks normal.[1][2] Your doctor will then look at free testosterone.
Does losing weight raise or lower SHBG?
Higher BMI is linked to lower SHBG, and very low body weight or eating disorders are linked to higher SHBG.[2][4] Weight change can therefore shift SHBG in either direction, which is one reason results should be read in context.
How can I lower my SHBG naturally?
The reliable path is treating the cause: correcting an overactive thyroid, managing liver disease, reviewing medicines with your prescriber, restoring adequate nutrition if you are underweight and quitting smoking.[1][3][4] No supplement is an established treatment for high SHBG.
References
- MedlinePlus (U.S. National Library of Medicine). SHBG Blood Test. medlineplus.gov/lab-tests/shbg-blood-test
- Lab Tests Online UK. Sex Hormone Binding Globulin (SHBG). labtestsonline.org.uk/tests/shbg
- Labcorp. Sex Hormone Binding Globulin: reference interval and clinical significance. labcorp.com
- Circulating sex hormones in relation to anthropometric, sociodemographic and behavioural factors in an international dataset of 12,300 men. PLoS One. 2017. PubMed 29281666
- The Journal of Urgent Care Medicine. Evaluating Decreased Libido: The Lowdown on Low T. jucm.com
These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease. This article is for information only and is not medical advice.
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