Short answer: Both deliver estradiol. Climara is a patch changed once a week, starting at 0.025 mg a day for every approved use.1 Estradiol tablets are taken by mouth, usually 1 to 2 mg daily to start for menopause symptoms, often in cycles.2 Both carry estrogen boxed warnings, and women with a uterus generally add a progestogen. Neither label compares the two.
| Climara | Estradiol tablets | |
|---|---|---|
| Form | Patch on the lower belly or upper buttock, never on or near the breasts; 0.025 to 0.1 mg a day in six strengths1 | Tablet by mouth; 0.5, 1 and 2 mg2 |
| Schedule | One patch, changed every 7 days1 | Daily, often cyclic, for example 3 weeks on and 1 week off2 |
| Hot flashes: starting dose | 0.025 mg a day, adjusted by response1 | 1 to 2 mg daily, adjusted to control symptoms2 |
| Osteoporosis prevention | 0.025 mg a day1 | Lowest effective dose not determined; only if non-estrogen medicines are not suitable2 |
| Side effect data | Breast pain 5%, 8% and 29% on 0.025, 0.05 and 0.1 mg vs 4% on placebo; headache 5% to 18% vs 10%1 | Listed without percentages, including headache, breast pain and irregular bleeding2 |
| Missed dose | Apply a new patch as soon as possible1 | No rule in the label2 |
| Boxed warning | WARNING: ENDOMETRIAL CANCER, CARDIOVASCULAR DISORDERS, PROBABLE DEMENTIA and BREAST CANCER1 | Two headings: ESTROGENS INCREASE THE RISK OF ENDOMETRIAL CANCER, and CARDIOVASCULAR AND OTHER RISKS2 |
Climara was tested against placebo. In an 11-week study of 214 women wearing patches 3 weeks on and 1 week off, weekly hot flashes fell 67% on 0.05 mg and 72% on 0.1 mg, vs 18.1% on placebo. In a second study of 187 women, 0.025 mg beat placebo at weeks 4 and 12.1 The estradiol tablets label reports no trials of its own tablets and gives no side-effect rates; its trial tables come from the Women's Health Initiative study of a different pill, oral conjugated estrogens with medroxyprogesterone acetate.2 These numbers come from separate trials with different people, lengths and methods, so they are not a head-to-head comparison.
Both warnings draw on the Women's Health Initiative studies of oral conjugated estrogens 0.625 mg, with or without medroxyprogesterone acetate: more strokes and blood clots, more breast cancer with the combined pill, and more probable dementia in women 65 and older. The Climara label says whether those findings apply to other routes, such as a patch, is not known, and that the risks cannot be ruled out.12
Both say to use the lowest effective dose for the shortest time and to stop 4 to 6 weeks before surgery linked to clots if feasible. The tablets label also covers palliation of some breast and prostate cancers.12
Which, if either, fits is for your prescriber. More detail: Climara side effects, estradiol tablets side effects, the Climara and estradiol tablets dosing schedules, the estradiol patch and estradiol tablets missed-dose pages, the estradiol guide, and Vivelle-Dot vs estradiol tablets: how do the patch and the pill differ?.