Bio-identical Hormone Replacement Therapy: Evidence-Based Approach
FDA-approved hormone replacement therapy using standardized formulations is recommended over compounded bio-identical hormone therapy due to better safety monitoring, consistent quality, and established efficacy profiles. 1
Understanding Bio-identical Hormone Therapy
Bio-identical hormone therapy (BHT) refers to hormone preparations that are chemically identical to those produced by the human body. These include:
- 17-β estradiol (preferred over ethinylestradiol or conjugated equine estrogens) 2
- Micronized progesterone
- Testosterone
Key Differences from Conventional HRT
- Bio-identical hormones: Structurally identical to human endogenous hormones, often derived from plant extracts 3
- Conventional HRT: May include non-identical hormones like conjugated equine estrogens
Evidence-Based Recommendations
FDA-Approved vs. Compounded Bio-identical Hormones
- FDA-approved bio-identical hormones are recommended over compounded formulations 1, 3
- Compounded bio-identical hormones:
- Lack well-controlled studies examining safety and efficacy
- Have inconsistent quality control
- Often prescribed based on saliva tests without scientific validation 3
Indications for HRT
HRT is appropriate for:
- Treatment of menopausal symptoms (hot flashes, night sweats, vaginal dryness) 2, 1
- Prevention of osteoporosis and fractures 2, 1
- Treatment of symptoms of low estrogen in women with premature ovarian insufficiency (POI) 2
Contraindications
HRT should NOT be used in women with:
- Active liver disease
- History of breast cancer
- History of coronary heart disease
- Previous venous thromboembolism or stroke 1
Prescribing Algorithm
Step 1: Confirm Appropriate Candidate
- Assess menopausal symptoms and/or risk for osteoporosis
- Rule out contraindications
- For POI patients: HRT recommended until at least age 51 2, 1
Step 2: Select Appropriate Formulation
Estrogen component:
Progestogen component (for women with intact uterus):
- Micronized progesterone 200 mg orally for 12-14 days per month OR
- Medroxyprogesterone acetate 2.5 mg/day 1
Step 3: Monitoring
- Initial follow-up at 3-6 months
- Annual assessment including blood pressure, weight, lipid profile, and cancer screening 1
- Adjust dose based on symptom control and side effects
Important Risks and Benefits
Benefits
- Relief of menopausal symptoms 1, 4
- Prevention of osteoporosis and fractures 2, 1
- Possible cardiovascular benefits when started early in menopause 4
Risks
- Increased risk of stroke and venous thromboembolism 2, 1
- Possible increased risk of breast cancer with long-term use 2, 1
- Increased risk of gallbladder disease 2
- Endometrial cancer risk with unopposed estrogen in women with intact uterus 2
Special Considerations
Women with Hypertension
- Transdermal estradiol is the preferred method of delivery 2
Women with Endometriosis
- Combined estrogen/progestogen therapy recommended to prevent disease reactivation 2
Women with BRCA1/2 Mutations
- HRT is a treatment option after prophylactic bilateral salpingo-oophorectomy if no personal history of breast cancer 2
Common Pitfalls to Avoid
Using compounded bio-identical hormones based on saliva testing
- No scientific evidence supports customizing hormones based on saliva tests 3
Assuming "natural" means safer
Continuing HRT indefinitely without reassessment
- Use lowest effective dose for shortest duration consistent with treatment goals 1
Prescribing unopposed estrogen to women with intact uterus
- Always add progestogen to protect the endometrium 2
By following these evidence-based guidelines, clinicians can appropriately prescribe hormone replacement therapy that balances symptom relief with safety considerations.