Route/form | Estrogen | Low | Standard | High | |||
---|---|---|---|---|---|---|---|
Oral | Estradiol | 0.5–1 mg/day | 1–2 mg/day | 2–4 mg/day | |||
Estradiol valerate | 0.5–1 mg/day | 1–2 mg/day | 2–4 mg/day | ||||
Estradiol acetate | 0.45–0.9 mg/day | 0.9–1.8 mg/day | 1.8–3.6 mg/day | ||||
Conjugated estrogens | 0.3–0.45 mg/day | 0.625 mg/day | 0.9–1.25 mg/day | ||||
Esterified estrogens | 0.3–0.45 mg/day | 0.625 mg/day | 0.9–1.25 mg/day | ||||
Estropipate | 0.75 mg/day | 1.5 mg/day | 3 mg/day | ||||
Estriol | 1–2 mg/day | 2–4 mg/day | 4–8 mg/day | ||||
Ethinylestradiola | 2.5–10 μg/day | 5–20 μg/day | – | ||||
Nasal spray | Estradiol | 150 μg/day | 300 μg/day | 600 μg/day | |||
Transdermal patch | Estradiol | 25 μg/dayb | 50 μg/dayb | 100 μg/dayb | |||
Transdermal gel | Estradiol | 0.5 mg/day | 1–1.5 mg/day | 2–3 mg/day | |||
Vaginal | Estradiol | 25 μg/day | – | – | |||
Estriol | 30 μg/day | 0.5 mg 2x/week | 0.5 mg/day | ||||
IM or SC injection | Estradiol valerate | – | – | 4 mg 1x/4 weeks | |||
Estradiol cypionate | 1 mg 1x/3–4 weeks | 3 mg 1x/3–4 weeks | 5 mg 1x/3–4 weeks | ||||
Estradiol benzoate | 0.5 mg 1x/week | 1 mg 1x/week | 1.5 mg 1x/week | ||||
SC implant | Estradiol | 25 mg 1x/6 months | 50 mg 1x/6 months | 100 mg 1x/6 months | |||
Footnotes: a = No longer used or recommended, due to health concerns. b = As a single patch applied once or twice per week (worn for 3–4 days or 7 days), depending on the formulation. Note: Dosages are not necessarily equivalent. Sources: [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] |
These preparations differ widely in their oral potencies; e.g., a dose of 0.625 mg of conjugated estrogens generally is considered equivalent to 5 to 10 μg of ethinyl estradiol.
The potency, and therefore the doses, of these estrogen preparations differ, but they differ little in efficacy [9]. In general, 0.625 mg of conjugated estrogens or esterified estrogen is considered equivalent to 1 mg of micronized 17-beta estradiol, 0.05 mg of transdermal estradiol, or 5 mcg of ethinyl estradiol (table 1). (See 'Dose equivalents' below.) [...] A transdermal dose of 50 mcg/day [5] is approximately equivalent to 1 mg of oral 17-beta estradiol and a 0.625 mg daily oral dose of conjugated estrogens [1]. [...] "Ultra-low doses" of estrogen (transdermal estradiol 0.014 mg/day and oral micronized 17-beta estradiol 0.25 mg/day) also appear to prevent bone loss [10,20] and are effective for hot flashes in some women. [...] Dose equivalents — Many studies of the safety and efficacy of postmenopausal estrogen have used conjugated estrogen 0.625 mg. This is considered to be standard-dose estrogen; low-dose preparations, in general, contain one-half the standard dose. The doses of other estrogens that are similarly effective for the treatment of hot flashes as 0.625 mg of CEE include (table 1): ● 1 mg micronized 17-beta estradiol. ● 50 mcg/day transdermal 17-beta estradiol. ● 1.25 mg piperazine estrone sulfate. ● Estradiol gels and sprays are available in different strengths and delivery systems (pump, foil packets). Dosing equivalents depend upon the individual preparation. Measurement of estradiol levels may be warranted when trying to adjust dosing.