How to normalize free testosterone and Sex Hormone-Binding Globulin (SHBG) levels in women?

Normalizing Free Testosterone and SHBG Levels in Women

Weight management through regular physical activity and dietary modifications is the most effective non-pharmacological intervention to normalize Sex Hormone-Binding Globulin (SHBG) levels and increase free testosterone levels in women. 1

Understanding Hormone Balance in Women

Free testosterone represents the metabolically active fraction of testosterone that is not bound to proteins like SHBG or albumin 2. In women, maintaining proper balance is crucial as:

• Total testosterone levels in women are approximately 15-25 times lower than in men 2
• SHBG binds tightly to testosterone, reducing its bioavailability
• Abnormal levels can lead to various health issues including menstrual irregularities and sexual dysfunction

Factors Affecting SHBG and Free Testosterone

Lifestyle Modifications (First-Line Approach)

• Weight management: The Obesity Society recommends weight reduction for overweight or obese women to normalize SHBG levels 1
• Physical activity: Regular exercise improves metabolic health and helps regulate hormone levels 1
• Nutrition:
  • Ensure sufficient zinc and vitamin D intake to support testosterone production 1
  • Avoid excessive alcohol consumption 1
  • Be cautious with foods like licorice and grapefruit juice that can affect hormone metabolism 1

Medical Interventions

1. For women on hormonal contraceptives:

   • Consider discontinuing or switching to non-hormonal contraception or progestin-only options if SHBG is elevated 1
   • Oral contraceptives containing ethinyl estradiol with levonorgestrel can increase SHBG and decrease free testosterone 3

2. For women on HRT:

   • Consider adjusting dose or switching to transdermal administration, which has less impact on SHBG than oral routes 1

3. For menstrual irregularities:

   • Consider cyclic progestogens as recommended by the Endocrine Society 1

Addressing Underlying Conditions

Thyroid Dysfunction

• Hypothyroidism is associated with lower SHBG levels 4
• Thyroid hormone therapy increases SHBG levels in both normal and hypothyroid patients 4
• Monitor thyroid function with TSH and free T4 tests 1

Other Related Conditions

• Evaluate for PCOS, which can affect testosterone levels 1
• Consider liver function, as liver disease can affect hormone metabolism 1
• Assess nutritional status, particularly in women with low BMI 1

Monitoring and Follow-up

• Measure SHBG and free testosterone levels every 3-6 months 1
• Use calculated free testosterone (cFT) rather than free androgen index (FAI) 1
• Comprehensive hormone panel should include:
  • SHBG levels
  • Total and free testosterone
  • Estradiol
  • FSH and LH
  • Thyroid function tests 1

Reference Ranges

For a typical 30-year-old woman, normal ranges are:

• Total testosterone: 15-46 ng/dL (520-1595 pmol/L)
• Free testosterone: 1.2-6.4 pg/mL (4.16-22.2 pmol/L)
• SHBG: 18-86 nmol/L 5

Common Pitfalls to Avoid

1. Ignoring cyclical variations: While testosterone shows some variation across the menstrual cycle, the changes are relatively small compared to overall variability, so reference ranges can be applied regardless of cycle day 5

2. Relying solely on total testosterone: Free testosterone is the metabolically active fraction and should be measured alongside SHBG for accurate assessment 2

3. Overlooking underlying conditions: Always evaluate for thyroid dysfunction, PCOS, and liver disease before initiating treatment 1

4. Using inappropriate testing methods: Equilibrium dialysis and ultrafiltration are reference methods for free testosterone measurement, while analog immunoassays may be less reliable 2