Letrozole for Ovulation Induction in PCOS: Meta-Analysis
Human Reproduction Update (2014)
Higher live birth rates than clomiphene (27.5% vs 19.1%), establishing letrozole as preferred ovulation induction agent.
Letrozole
Oral tablet (2.5mg)Available in all 50 statesMarketing purposes only. Actual medications, if prescribed, are dispensed by a licensed pharmacy.
hormones
LetrozoleLetrozole
Third-generation nonsteroidal aromatase inhibitor that reversibly blocks CYP19A1, suppressing estrogen synthesis by 97 to 99%. Used in breast cancer and widely off-label in men for estradiol management during TRT and male infertility.
Most potent reversible aromatase inhibition
Raises endogenous testosterone in men
Effective ovulation induction (superior to clomiphene for PCOS)
No commitment · HSA/FSA eligibleNo commitment · HSA/FSA eligible
How it works
Mechanism of action
Competitively and reversibly binds CYP19A1 (aromatase), blocking conversion of androgens to estrogens. In men, reduces circulating estradiol, disinhibiting HPG axis feedback and increasing LH, FSH, and endogenous testosterone.
The baseline panel.
Every Marek client receives this baseline panel before a provider review. Your provider may add additional biomarkers based on your health history, symptoms, and goals, pulling from 1,000+ available markers. See more biomarkers →
Hormone Profile
12 markers
Sex hormones
- Total TestosteroneLC/MS
- Free TestosteroneEquilibrium Dialysis
- Estradiol, Sensitive / UltrasensitiveLC/MS
- Sex Hormone Binding Globulin (SHBG)
- ProgesteroneLC/MSFemale panel
- Prolactin
- Luteinizing Hormone (LH)
- Follicle-Stimulating Hormone (FSH)
- hCG, Total, QuantitativeFemale panel, pre-menopause
Adrenals & neurosteroids
- Cortisol
- DHEA-S
Growth hormone / IGF-1
- Insulin-Like Growth Factor I (IGF-1)
Thyroid Status
3 markers
Thyroid hormones
- Thyroid Stimulating Hormone (TSH)
- Free T4
- Free T3
Heart Health
9 markers
Cardiovascular health
- Total Cholesterol
- HDL Cholesterol
- LDL Cholesterol
- LDL:HDL Ratio
- VLDL Cholesterol
- Triglycerides
- Apolipoprotein-B (ApoB)
- C-Reactive Protein, High Sensitivity (hsCRP)
- Lipoprotein(a) (Lp(a))
Metabolism
3 markers
Insulin sensitivity
- Blood Glucose
- Fasting Insulin
- HbA1c
Organ Function
26 markers
Liver & pancreas
- AST
- ALT
- Bilirubin, Total
- γ-Glutamyl Transferase (GGT)
Kidney function
- BUN
- Creatinine w/ eGFR
Comprehensive Metabolic Panel (CMP)
- Glucose
- Blood Urea Nitrogen (BUN)
- Creatinine
- eGFR
- BUN/Creatinine Ratio
- Sodium
- Potassium
- Chloride
- Carbon Dioxide, Total
- Calcium
- Protein, Total
- Albumin
- Globulin, Total
- Albumin/Globulin (A/G) Ratio
- Alkaline Phosphatase (ALP)
- AST
- ALT
Prostate health
- Prostate-Specific Antigen (PSA)Male panel
- Free PSAMale panel
- % Free PSAMale panel
Nutrient Status
31 markers
Vitamins & minerals
- Vitamin D, 25-OHD (25-Hydroxy)
- Magnesium, RBC
Iron status
- Iron
- Iron Saturation
- TIBC
- UIBC
- Ferritin
Complete Blood Count (CBC)
- White Blood Count (WBC)
- Red Blood Count (RBC)
- Hemoglobin (Hgb)
- Hematocrit (HCT)
- MCV
- MCH
- MCHC
- Red Cell Distribution Width (RDW)
- Platelets
- Neutrophils
- Neutrophils (Absolute)
- Lymphocytes
- Lymphocytes (Absolute)
- Neutrophil/Lymphocyte Ratio
- Monocytes
- Monocytes (Absolute)
- Eosinophils
- Eosinophils (Absolute)
- Basophils
- Basophils (Absolute)
- Immature Cells
- Immature Granulocytes
- Immature Granulocytes (Absolute)
- NRBC, w/ Reflex for Immature Cells
Clinical evidence
The research behind Letrozole.
Safety profile
Monitoring & safety information.
Commonly reported side effects
- Hot flashes
- Joint pain / arthralgia
- Fatigue
- Bone loss (long-term)
- Decreased libido (if estradiol over-suppressed)
Less common but serious risks
- Bone mineral density loss and fracture risk
- Over-suppression of estradiol in men (joint pain, mood depression, low libido)
Generally not appropriate for
- Premenopausal women (breast cancer)
- Pregnancy
- Severe hepatic impairment
Typical monitoring
- Serum estradiol (critical, avoid over-suppression; target 20 to 30 pg/mL in men)
- Testosterone
- LH, FSH
- DXA (long-term)
- Lipid panel
FAQ
Quick answers.
Third-generation nonsteroidal aromatase inhibitor that reversibly blocks CYP19A1, suppressing estrogen synthesis by 97 to 99%. Used in breast cancer and widely off-label in men for estradiol management during TRT and male infertility.
Most potent reversible aromatase inhibition. Raises endogenous testosterone in men. Effective ovulation induction (superior to clomiphene for PCOS).
Common side effects include: hot flashes, joint pain / arthralgia, fatigue, bone loss (long-term), decreased libido (if estradiol over-suppressed). Most side effects are dose-dependent and may resolve with continued use or dose adjustment.
Third-generation nonsteroidal aromatase inhibitor that reversibly blocks CYP19A1, suppressing estrogen synthesis by 97 to 99%. Used in breast cancer and widely off-label in men for estradiol management during TRT and male infertility.
Treatments are dependent on licensed clinical prescription. Client costs vary based on individual labs and panel in treatments and services.