Also indexed as: Alora, Climara, Dalergen, Delestrogen,
Depo-Estradiol, Depogen, DepoGynogen, E-Cypionate, Escalim, Esclim, Estinyl, Estrace,
Estraderm, Estragyn LA 5, Estring, Estro-Cyp, Estro-LA, Ethinyl Estradiol, FemPatch, Gynodiol,
Gynogen LA, Menaval, Noven, Vagifem, Vivelle
Estradiol is a semisynthetic human estrogenic hormone used to treat menopausal symptoms, to prevent osteoporosis in postmenopausal women, and as
replacement therapy in other conditions of inadequate estrogen production.
Estradiol is available as an oral drug, a transdermal (skin) patch, and as a vaginal
cream.
Summary of
Interactions with Vitamins, Herbs, and Foods
In some cases, an herb or supplement may appear in more than one category, which may seem
contradictory. For clarification, read the full article for details about the summarized
interactions.
Avoid: Adverse interaction—Avoid these supplements when taking this
medication because taking them together may cause undesirable or dangerous results. |
Grapefruit*
Quercetin*
|
Check: Other—Before taking any of these supplements or eating any of
these foods with your medication, read this article in full for details. |
Vitamin D
|
| Depletion or interference |
None known
|
| Side effect reduction/prevention |
None known
|
| Supportive interaction |
None known
|
| Reduced drug
absorption/bioavailability |
None known
|
An asterisk (*) next to an item in the summary indicates that the
interaction is supported only by weak, fragmentary, and/or contradictory scientific
evidence.
Interactions with Dietary Supplements
Quercetin
Studies have shown that grapefruit juice significantly increases estradiol levels in the
blood.1 2 One of the flavonoids found in grapefruit juice is quercetin.
In a test tube study, quercetin was found to change estrogen metabolism in human liver cells
in a way that increases estradiol levels and reduces other forms of estrogen.3 This
effect is likely to increase estrogen activity in the body. However, the levels of quercetin
used to alter estrogen metabolism in the test tube were much higher than levels found in the
body after supplementing with quercetin.
There is evidence from test tube stuudies that another flavonoid in grapefruit juice,
naringenin, also has estrogenic activity.4 It has yet to be shown that dietary or
supplemental levels of quercetin (or naringenin) could create a significant problem.
Vitamin
D
In controlled studies, the addition of 300 IU per day of vitamin D3 (cholecalciferol) did not
improve the bone-preserving or fracture-preventing effects of hormone replacement with
estradiol plus a progestin (a synthetic form of progesterone) in postmenopausal women without
osteoporosis.5 6
However, in a controlled study of osteoporotic women, only those receiving both hormone
replacement and vitamin D had increases in bone density of the hip; no improvement occurred in
the hip with hormones alone.7 More research is needed to determine conclusively
when vitamin D is important to add to hormone replacement.
Interactions with Foods and Other Compounds
Grapefruit
In a small, controlled study of women with surgically removed ovaries, estradiol levels in the
blood were significantly higher after estradiol was taken with grapefruit juice than when
estradiol was taken alone.8 These results have been independently
confirmed,9 suggesting that women taking oral estradiol should probably avoid
grapefruit altogether.
References:1. Schubert W, Cullberg G, Edgar B, Hedner T. Inhibition of 17
beta-estradiol metabolism by grapefruit juice in ovariectomized women. Maturitas
1994;20:155–63.
2. Weber A, Jager R, Borner A, et al. Can grapefruit juice influence
ethinylestradiol bioavailability? Contraception 1996;53:41–7.
3. Schubert W, Eriksson U, Edgar B, et al. Flavonoids in grapefruit juice
inhibit the in vitro hepatic metabolism of 17 beta-estradiol. Eur J Drug Metab
Pharmacokinet 1995;3:219–24.
4. Kuiper GG, Lemmen JG, Carlsson B, et al. Interaction of estrogenic
chemicals and phytoestrogens with estrogen receptor beta. Endocrinology
1998;139:4252–63.
5. Komulainen M, Kroger H, Tuppurainen MT, et al. Prevention of femoral
and lumbar bone loss with hormone replacement therapy and vitamin D3 in early postmenopausal
women: a population-based 5-year randomized trial. J Clin Endocrinol Metab
1999;84:546–52.
6. Komulainen MH, Kroger H, Tuppurainen MT, et al. HRT and Vit D in
prevention of non-vertebral fractures in postmenopausal women; a 5 year randomized trial.
Maturitas 1998;31:45–54.
7. Tuppurainen MT, Komulainen M, Kroger H, et al. Does vitamin D
strengthen the increase in femoral neck BMD in osteoporotic women treated with estrogen?
Osteoporos Int 1998;8:32–8.
8. Schubert W, Cullberg G, Edgar B, Hedner T. Inhibition of 17
beta-estradiol metabolism by grapefruit juice in ovariectomized women. Maturitas
1994;20:155–63.
9. Weber A, Jager R, Borner A, et al. Can grapefruit juice influence
ethinylestradiol bioavailability? Contraception 1996;53:41–7.