Estradiol Sublingual
Estrace (used sublingually)
Half-life
4.5 hr
Time to Peak
45 min
Steady State
~1 days
Bioavailability
25%
Dose Range
0.5–4 mg
Frequency
Twice daily
Overview
Oral micronized estradiol tablets dissolved under the tongue (off-label use). Bypasses first-pass liver metabolism, achieving ~5x higher bioavailability than swallowed oral (~25% vs ~5%). Produces sharp E2 spikes (200-500+ pg/mL within 30-60 min) followed by rapid decline. Dose is typically split 2-3 times daily.
Mechanism of Action
Micronized 17β-estradiol absorbed through oral mucosa directly into systemic circulation, bypassing hepatic first-pass metabolism. Lower E1:E2 ratio than oral.
Dosing Information
| Route | Dose Range | Half-life | Tmax | Frequency |
|---|---|---|---|---|
| Sublingual | 0.5–4 mg | 4.5 hr | 45 min | Twice daily, three times daily |
Storage & Handling
Room temperature — Standard micronized estradiol tablets (e.g., Estrace generic). Dissolve under tongue; avoid swallowing saliva during dissolution.
Used in Regimens
Estradiol Sublingual is not currently part of any catalog regimen.
Data Sources
- Peer-reviewed Price et al. 1997 — Sublingual estradiol pharmacokinetics
- Peer-reviewed Kuhl 2005 — Pharmacology of estrogens and progestogens (comprehensive review)
Related Tools
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