Estrogen (Estradiol)
Also known as: Estradiol · E2 · 17β-Estradiol · Bioidentical Estrogen · Estrace · Vivelle
The primary female sex hormone critical for reproductive health, bone density, cardiovascular protection, brain function, and skin health in women — and important for men's health at optimal levels.
Overview
Estradiol (E2) is the most potent and predominant form of estrogen in the human body. In women, it is primarily produced by the ovaries and plays a central role in reproductive health, menstrual cycle regulation, and the maintenance of bone, cardiovascular, and neurological health. During menopause, estradiol levels decline dramatically, leading to symptoms including hot flashes, vaginal atrophy, bone loss, cognitive changes, and increased cardiovascular risk. Bioidentical Hormone Replacement Therapy (BHRT) using 17β-estradiol has become the gold standard for menopausal symptom management. Routes include transdermal patches (preferred for cardiovascular safety), topical creams/gels, and oral formulations.
In men, estradiol is produced via aromatization of testosterone and is essential at physiological levels (20-35 pg/mL) for bone health, libido, cardiovascular protection, and neuroprotection. Both excess and deficiency of estradiol in men can cause significant health issues. Modern health optimization focuses on maintaining estradiol in the optimal range rather than simply suppressing it.
Mechanism of Action
Binds to estrogen receptors ERα and ERβ, which are nuclear transcription factors that regulate gene expression in target tissues. Also activates rapid non-genomic signaling via membrane-bound GPR30/GPER. Modulates bone remodeling (inhibits osteoclasts), cardiovascular function (promotes NO synthesis, vasodilation), neuronal plasticity (BDNF expression), and lipid metabolism.
Key Benefits
Potential Side Effects
Common Stacks
This peptide is commonly combined with the following compounds for synergistic effects:
Known Interactions
The following interactions have been documented for Estrogen (Estradiol). Always consult a healthcare professional before combining compounds.
Contraindicated (1)
Anastrozole blocks estrogen production. Using it alongside estrogen replacement therapy is counterproductive — it would negate the estrogen being administered.
Synergistic (1)
Standard HRT combination for women. Progesterone balances estrogen's proliferative effects on the endometrium, reducing cancer risk while maintaining hormonal benefits.
Scientific References
Quick Reference
Typical Dose
0.025-0.1 mg/day (patch); 0.5-2 mg/day (oral); varies by route
Frequency
Daily (oral/topical) or twice weekly (patch)
Route
Transdermal patch (preferred); topical cream/gel; oral; vaginal
Half-Life
~13-20 hours (oral); sustained release (transdermal)
Cycle Length
Ongoing for HRT; regular monitoring every 6-12 months
FDA Status
FDA approved for menopausal symptoms and osteoporosis prevention
Need to calculate dosing?
Use our reconstitution calculator to determine exact syringe measurements.
Open CalculatorThis information is for educational purposes only. Consult a qualified healthcare professional before using any peptide. Dosing information reflects commonly reported protocols and may not be appropriate for everyone.
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