ESTHER Study: Transdermal vs Oral Estradiol and VTE Risk
Circulation (2007)
Oral estrogen 4-fold increased VTE risk vs non-users; transdermal estradiol had no significant increase, establishing transdermal as the safer route.
Estradiol
Oral tablet (0.5 to 2mg), Transdermal patch (0.025 to 0.1mg/24hr), Topical cream (4 to 16mg/mL), Injectable, valerate or cypionate, Vaginal creamAvailable in all 50 statesMarketing purposes only. Actual medications, if prescribed, are dispensed by a licensed pharmacy.
hormones
EstradiolEstradiol
The most potent endogenous estrogen, used in HRT for perimenopausal/postmenopausal women and gender-affirming therapy. Route significantly affects metabolism and safety, transdermal avoids hepatic first-pass and thromboembolic risk.
Highly effective relief of menopausal symptoms
Prevents bone loss and fractures
Improves mood, cognition, and sleep
Cardiovascular benefit when initiated within 10 years of menopause
No commitment · HSA/FSA eligibleNo commitment · HSA/FSA eligible
How it works
Mechanism of action
Binds estrogen receptors ERα and ERβ throughout the body, modulating gene transcription in uterus, breast, bone, cardiovascular system, and CNS. Oral undergoes first-pass hepatic metabolism, increasing clotting factors, bypassed by transdermal/injectable routes.
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 Estradiol.
The Timing Hypothesis for Estrogen and Cardiovascular Protection
Climacteric (2015)
Women initiating estrogen within 10 years of menopause showed cardiovascular benefit; >10 years was associated with harm.
Safety profile
Monitoring & safety information.
Commonly reported side effects
- Breast tenderness
- Nausea (oral)
- Headache
- Fluid retention
- Spotting
Less common but serious risks
- Endometrial hyperplasia/cancer without progestogen
- VTE (higher with oral vs transdermal)
- Breast cancer risk (with combined estrogen-progestogen)
- Gallbladder disease
Generally not appropriate for
- Undiagnosed abnormal uterine bleeding
- Known estrogen-dependent cancer
- Active VTE or arterial thromboembolic disease
- Active liver disease
- Pregnancy
Typical monitoring
- Serum estradiol
- FSH/LH
- Endometrial surveillance (ultrasound)
- Mammography
- Lipid panel
- Blood pressure
- DXA scan
FAQ
Quick answers.
The most potent endogenous estrogen, used in HRT for perimenopausal/postmenopausal women and gender-affirming therapy. Route significantly affects metabolism and safety, transdermal avoids hepatic first-pass and thromboembolic risk.
Highly effective relief of menopausal symptoms. Prevents bone loss and fractures. Improves mood, cognition, and sleep. Cardiovascular benefit when initiated within 10 years of menopause. Transdermal route has lower thrombotic risk.
Common side effects include: breast tenderness, nausea (oral), headache, fluid retention, spotting. Most side effects are dose-dependent and may resolve with continued use or dose adjustment.
The most potent endogenous estrogen, used in HRT for perimenopausal/postmenopausal women and gender-affirming therapy. Route significantly affects metabolism and safety, transdermal avoids hepatic first-pass and thromboembolic risk.
Treatments are dependent on licensed clinical prescription. Client costs vary based on individual labs and panel in treatments and services.