E3N Cohort: Breast Cancer Risk with Bioidentical Progesterone
Breast Cancer Research and Treatment (2008)
Estrogen + bioidentical progesterone showed breast cancer risk not significantly different from 1.0, unlike estrogen + synthetic progestin.
How it works
Marek's Guided Optimization® Program combines advanced lab testing, a dedicated health coach and medical provider, and a personalized treatment plan, all built around your data.
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The process
1
Start your assessment
Complete your 45-min intake assessment
2
Get your labs drawn
4,000 partnered lab locations nationwide
3
Review with your coach
Screen-by-screen lab review
4
Receive your protocol
Treatment delivered to your door
Why Marek
The only program pairing you with a dedicated health coach and medical provider, built on precision diagnostics, with no subscription required.
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Meet our co-founder
Derek
Co-Founder · MPMD Podcast
"Over time, I found it incredibly difficult to get medical oversight for myself and my family that reflected the latest research, and that was preventative. That's why I started Marek Health."
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What we test
Every client's lab panel is hand-selected from 1,000+ available biomarkers, built around their specific goals.
Panel categories
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Treatments
700+ medical provider-prescribed therapies built from your labs. Browse by category or explore the full formulary.
Progesterone (Bioidentical)
Oral SR capsule (50 to 300mg), Sublingual troche/tablet (200mg), Injectable (50mg/mL), Vaginal suppository (200mg)Not available in all statesMarketing purposes only. Actual medications, if prescribed, are dispensed by a licensed pharmacy.
hormones
Progesterone (Bioidentical)Progesterone (Bioidentical)
Bioidentical progesterone, chemically identical to endogenous progesterone. Used for endometrial protection in HRT, luteal phase support, sleep enhancement, and neurosteroid function. Oral route converts significantly to neuroactive allopregnanolone (GABAergic).
Bioidentical, favorable safety vs synthetic progestins
Oral route provides calming allopregnanolone metabolites
Favorable breast cancer safety vs synthetic progestins (E3N data)
Neurosteroid benefits: reduces anxiety, improves sleep
No commitment · HSA/FSA eligibleNo commitment · HSA/FSA eligible
How it works
Mechanism of action
Binds progesterone receptors PR-A and PR-B, counteracting estrogen-driven endometrial proliferation. In CNS, metabolite allopregnanolone acts as positive allosteric modulator of GABA-A receptors, producing anxiolytic and sedative effects.
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 Progesterone (Bioidentical).
Oral Progesterone and Sleep in Perimenopausal Women
Menopause (2018)
300mg at bedtime significantly improved sleep efficiency and reduced waking after sleep onset.
Safety profile
Monitoring & safety information.
Commonly reported side effects
- Drowsiness/sedation (oral, take at bedtime)
- Dizziness
- Bloating
- Breast tenderness
Less common but serious risks
- Sedation, avoid driving after oral dose
- Peanut allergy caution (Prometrium contains peanut oil)
Generally not appropriate for
- Undiagnosed abnormal uterine bleeding
- Active liver disease (oral route)
- Peanut allergy (Prometrium brand)
Typical monitoring
- Serum progesterone
- Endometrial thickness
- Symptom review (sedation, mood)
- Liver function (oral)
FAQ
Quick answers.
Bioidentical progesterone, chemically identical to endogenous progesterone. Used for endometrial protection in HRT, luteal phase support, sleep enhancement, and neurosteroid function. Oral route converts significantly to neuroactive allopregnanolone (GABAergic).
Bioidentical, favorable safety vs synthetic progestins. Oral route provides calming allopregnanolone metabolites. Favorable breast cancer safety vs synthetic progestins (E3N data). Neurosteroid benefits: reduces anxiety, improves sleep.
Common side effects include: drowsiness/sedation (oral, take at bedtime), dizziness, bloating, breast tenderness. Most side effects are dose-dependent and may resolve with continued use or dose adjustment.
Bioidentical progesterone, chemically identical to endogenous progesterone. Used for endometrial protection in HRT, luteal phase support, sleep enhancement, and neurosteroid function. Oral route converts significantly to neuroactive allopregnanolone (GABAergic).
Treatments are dependent on licensed clinical prescription. Client costs vary based on individual labs and panel in treatments and services.