경구 에스트라디올 (알약)

雌激素 A

口服雌二醇

Oral Estradiol (Estrace, Progynova)

Oral

Oral estradiol (swallowing pills) is the most globally accessible formulation of estrogen. While VTE (blood clot) risks are slightly higher than transdermal administration, it remains a highly acceptable and standard choice for young users without preexisting risk factors.

Oral Estradiol (EV) — 4mg, T½=16h, 시간 (h)

Pharmacology

First-Pass Metabolism (The Liver)

When oral estradiol is swallowed and absorbed through the gastrointestinal tract, it must first pass through the liver before hitting your general bloodstream. This is known as “First-Pass Metabolism” ^[1] :

• The massive concentration of E2 hitting the liver directly stimulates the synthesis of clotting factors, which is what elevates VTE risk.
• It also impacts SHBG (Sex Hormone-Binding Globulin) and triglyceride levels.
• This first-pass effect destroys the vast majority of the drug, resulting in an oral bioavailability of merely 3-5%.
• Forms like Estradiol Valerate (Progynova) are simply cleaved into raw estradiol within the liver.

Dosage Conversions

Different formulations of oral pills contain different amounts of actual estradiol base ^[1] :

2 mg Estradiol Valerate (e.g., Progynova) ≈ 1.5 mg Estradiol (e.g., Estrace)

Keep this conversion in mind when reading online dosage discussions, as American forums often default to Estrace (pure Estradiol/Estradiol Hemihydrate), while European and Asian forums frequently default to Progynova (Estradiol Valerate).

VTE (Blood Clot) Risk Data

Route	Relative Risk (RR)	95% CI	Note
Oral Estradiol	1.48	1.27 - 1.72	VTE risk increased by roughly 48%
Transdermal Patch (Baseline)	0.97	0.79 - 1.19	No statistical difference from non-users

Oral estradiol increases VTE risk by roughly 48% (RR ≈ 1.48) compared to the non-medicated population ^[2] . While the relative risk is elevated, the absolute baseline risk for young, healthy populations is incredibly low (around 1-2 per 10,000 annually). Consequently, oral administration remains well within an acceptable safety margin for young individuals without preexisting risk factors.

Fatal Combo: Oral Estradiol + Oral CPA

Taking oral estradiol alongside oral Cyproterone Acetate (CPA) guarantees a stacked, double-compound VTE risk. CPA is inherently pro-coagulant ^[3] . When combined with the first-pass liver effects of oral estrogen, the blood-clotting threat multiplies. If you must use CPA as your anti-androgen, you should absolutely transition to a transdermal estrogen (patches or gel). See our Dose Limits & Contraindications page.

Dosage Recommendations

The following ranges integrate data from the Endocrine Society 2017 Guidelines ^[4] and WPATH SOC 8 ^[5] :

Stage	Dose (Estradiol Base)	Target E2 (pg/mL)	Timeline
Low Dose Start	2 mg/day	50-100	Months 1-6
Moderate Titration	4 mg/day	100-200	Months 6-12
Maintenance Phase	4-6 mg/day	100-200	12 Months+
Maximum Dose	8 mg/day	Not to exceed 200	Special circumstances only

Do Not Skip The Low Dose Phase

Even if you feel like the low dose is “doing nothing,” the first 6 months of a slow titration approach are fiercely critical for establishing healthy breast ductal branching. Starting at 6mg or 8mg to “speedrun” puberty frequently forces premature breast bud fusion, permanently crippling your final breast volume ^[6] . See our Breast Development deep dive.

Administration Methods

• Take your pills at roughly the same time every day to establish a routine.
• If taking 4 mg/day, splitting it (2 mg morning + 2 mg night) significantly smooths out blood concentration fluctuations.
• Taking pills with meals provides a marginal boost to absorption, but keeping a consistent schedule matters more.
• If you miss a dose, just wait and take your next dose as scheduled. Do not double up to compensate.

Target Audience & Contraindications

Oral estradiol is suitable for the following profiles ^{[4] [5]} :

Highly Recommended When:

• No VTE/clotting risk factors
• Age < 40
• BMI < 30
• Non-smoker
• No personal or family history of deep vein thrombosis
• No blood clotting disorders

Do Not Use Oral Administration (Switch to Transdermal):

• Age ≥ 40
• BMI ≥ 30
• Currently smoking or recently quit
• Personal or strong family history of VTE
• Known clotting factor abnormalities (e.g., Factor V Leiden)
• Currently combining HRT with CPA (Cyproterone Acetate)
• History of migraines with aura

Global Access

Pills remain the default standard for a vast majority of the globe:

• US/Canada: Often prescribed as generic Estradiol (Estrace) under informed-consent frameworks. Extremely cheap on insurance or GoodRx.
• UK/EU/Australia: Prescribed via official pathways (NHS, GICs) or private providers. Both Progynova (Valerate) and Estrofem (Hemihydrate) are standard.
• Global DIY Market: Pills are heavily trafficked across decentralized markets due to being easy to ship and difficult to break. Always verify the source.

Monitoring Advice

• When to draw blood: Always test immediately prior to taking your next dose. This is called measuring your “trough” levels ^[7] .
• Initial Phase: Test Sex Hormones + Liver Panel at Month 1. Check Hormones + Liver + Lipid panels at Month 3.
• Maintenance Phase: Get tested every 6 months.
• Clinical Target: Trough E2 between 100-200 pg/mL, T < 50 ng/dL.
• Safety Margin: If your trough E2 exceeds 200 pg/mL, seriously consider stepping down your pill count or moving to transdermal options.

Relationship to Sublingual Estrogen

Standard estradiol pills can also be dissolved under the tongue (Sublingual). This bypasses massive amounts of the liver first-pass metabolism, surging your bioavailability drastically. However, it requires dosing multiple times a day and creates wild rollercoaster-style spikes in your blood levels. If you wish to learn about taking your pills this way, see our Sublingual Administration page.

品牌图鉴

🇩🇪德国

补佳乐 Progynova

厂商

拜耳 (Bayer)

规格

2mg × 21片

外观

蓝色糖衣片

原研药，欧洲/国际版包装

🇨🇳中国

补佳乐 Progynova

厂商

拜耳 (Bayer China)

规格

1mg × 21片

外观

白色小圆糖衣片

中国大陆最常见制剂，线下药房可购，需处方

🇹🇭泰国

Progynova

厂商

拜耳 (Bayer Thailand)

规格

2mg × 28片

外观

蓝色糖衣片

泰国版，常见于代购渠道，与德国原研同配方

🇮🇳印度

Progynova

厂商

Zydus (拜耳印度授权)

规格

2mg × 28片

外观

蓝色糖衣片，印度包装

拜耳授权 Zydus Cadila 生产，价格较低，与原研同配方

🇹🇭泰国

Estrofem

厂商

Novo Nordisk

规格

2mg × 28片

外观

蓝色三角形薄膜衣片

微粉化雌二醇（非戊酸酯），适合舌下含服，泰国代购常见

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