How can I lower my sex hormone‑binding globulin (SHBG)?

How to Lower SHBG Levels

The most effective strategy to lower SHBG is to address insulin resistance and obesity through weight loss and metabolic optimization, as insulin directly inhibits hepatic SHBG synthesis. 1

Primary Approach: Metabolic Intervention

Weight loss and improving insulin sensitivity are the most powerful interventions for lowering SHBG. The mechanism is straightforward: insulin directly suppresses SHBG production in the liver, and this effect is amplified in states of insulin resistance and obesity. 1, 2

Key metabolic strategies include:

• Calorie restriction leads to reduced insulin levels, which subsequently lowers SHBG production through decreased inhibition of hepatic synthesis. 3
• Reducing body mass index (BMI) shows an inverse correlation with SHBG—as BMI decreases, SHBG levels fall due to improved insulin sensitivity. 1, 3
• Addressing central adiposity is particularly important, as truncal obesity is strongly associated with the insulin-mediated suppression of SHBG. 3
• Improving insulin resistance through lifestyle modification directly impacts hepatic SHBG gene expression by reducing the inhibitory effect of hyperinsulinemia. 2

The European Association for the Study of Obesity emphasizes that increased BMI inversely correlates with SHBG, making weight management the cornerstone intervention. 1

When Elevated SHBG is Pathological: Treat the Underlying Cause

If your SHBG is abnormally elevated (rather than needing to be lowered for metabolic reasons), the approach differs entirely:

Identify and correct these conditions:

• Hyperthyroidism: Correct thyroid overactivity, as thyroid hormones increase SHBG gene expression. 4, 1
• Hepatic disease: Manage liver pathology, as chronic liver disease markedly raises SHBG. 4, 1
• Medication review: Discontinue or substitute drugs that elevate SHBG, including anticonvulsants (phenytoin, carbamazepine), estrogens, and excessive thyroid hormone replacement. 4, 1
• HIV/AIDS: Optimize antiretroviral therapy if HIV is contributing to elevated SHBG. 4, 1

The American College of Physicians recommends treating the root cause of elevated SHBG rather than attempting direct SHBG suppression. 1

Pharmacological Options (Use Only When Clinically Indicated)

Medications that lower SHBG should never be used solely for SHBG reduction—they are only appropriate when treating other medical conditions. 1

Agents that decrease SHBG include:

• Glucocorticoids: Suppress hepatic SHBG synthesis but carry significant metabolic side effects. 1
• Testosterone or anabolic steroids: Directly lower SHBG but are only indicated for documented hypogonadism with symptoms. 1
• Growth hormone: Decreases SHBG but is reserved for growth hormone deficiency states. 1

The American College of Clinical Endocrinologists explicitly states these medications should only be used when clinically indicated for other conditions, not solely to manipulate SHBG levels. 1

Clinical Context: Why You Might Want Lower SHBG

In Polycystic Ovary Syndrome (PCOS):

• Low SHBG is characteristic of PCOS and contributes to increased free testosterone, worsening hyperandrogenic symptoms. 1
• Insulin resistance is the primary driver of low SHBG in PCOS patients, making metabolic intervention the logical therapeutic target. 1
• The American Society for Reproductive Medicine notes that addressing insulin resistance improves SHBG levels and overall metabolic health in PCOS. 1

In obesity and metabolic syndrome:

• Low SHBG serves as a biomarker of insulin resistance and metabolic dysfunction rather than a therapeutic target per se. 2
• The American Diabetes Association notes that SHBG levels progressively decline as metabolic syndrome components accumulate. 1

Important Caveats

Do not confuse the clinical scenarios:

• If SHBG is pathologically elevated (hyperthyroidism, liver disease, medications), treat the underlying cause to normalize it. 4, 1
• If SHBG is already low (obesity, insulin resistance, PCOS), further lowering is not therapeutic—instead, address the metabolic dysfunction driving the low SHBG. 1, 3

Avoid these pitfalls:

• Never use anabolic steroids or supraphysiologic androgens solely to lower SHBG, as this creates more problems than it solves. 1
• Recognize that very low SHBG in the context of obesity and insulin resistance is a marker of metabolic disease, not a therapeutic target for further reduction. 2, 3
• Calorie restriction is more effective than isocaloric low-fat diets for raising insulin sensitivity and thereby modulating SHBG. 3

Molecular Mechanism

The liver produces SHBG under complex hormonal and nutritional control. 2, 5 Monosaccharides (glucose, fructose) decrease SHBG expression by inducing lipogenesis, which reduces hepatic HNF-4α levels—a transcription factor critical for SHBG promoter activity. 2 This mechanism explains why SHBG is such a sensitive biomarker of insulin resistance and why low plasma SHBG levels predict the development of hyperglycemia and type 2 diabetes, especially in women. 2