Progesterone is a hormone from a corpus luteum, formed by the cyclical rupture of an
ovarian follicle. Progesterone is necessary for proper uterine and breast development and
function.
Where is it found?
Progesterone is produced in the female body in the ovaries. Progesterone production is high
during the luteal phase (second portion) of the menstrual cycle and low during the follicular
phase (first portion), as well as being low before puberty and after menopause.
Supplemental sources of progesterone are available in oral and cream forms, as well as
lozenges, suppositories, and injectable forms. “Natural” progesterone refers to
the molecule that is identical in chemical structure to the progesterone produced in the body,
even if the molecule is synthesized in a laboratory.
Progestins are found in oral contraceptive
pills and are used in conventional hormone replacement therapy.
Wild yam contains precursors to
progesterone (such as diosgenin) that can be converted through a chemical process in the
laboratory into progesterone—the exact same molecule made in the human body. However,
contrary to popular claims, the diosgenin in wild yams cannot be converted into progesterone
in the body.1 2 Women who require progesterone should consult their
physician and not rely on wild yam or other herbs.
Pregnenolone, another hormone produced by
the body, is converted by the body into progesterone. However, it is not clear what effect
supplementing with pregnenolone will have on progesterone production in the body.
Progesterone has been used
in connection with the following conditions (refer to the individual
health concern for complete information):
Who is likely to be deficient?
Postmenopausal women have reduced production of progesterone. While this
“deficiency” is normal, progesterone, including the natural forms of progesterone,
has been found to relieve menopausal symptoms
when used in combination with estrogen
replacement therapy.3
How much is usually taken?
The proper amount of progesterone for a woman should be determined in consultation with a
doctor. Some research with the natural, oral form of progesterone has used 200 mg per
day.4 Progesterone is used in much lower amounts—such as 20–70 mg per
day—by most doctors who prescribe topical natural progesterone. However, the ability of
skin-applied progesterone to achieve effective levels in the body is the source of
considerable debate.5 Although progesterone is a natural substance, oral
progesterone supplements are available by prescription only. High-dose topical progesterone
cream is also treated like a drug and requires a prescription. A few creams containing lower
amounts of progesterone are sold without prescription.
Are there any side effects or interactions?
Progesterone is a hormone and, as such, concerns about its inappropriate use have been
raised. A physician should be consulted before using this hormone as a supplement. Few side
effects have been associated with topical progesterone creams but can include skin reactions.
Effects of natural progesterone on breast
cancer risk remain unclear. Research has suggested both increased and reduced risk.
Synthetic progestins have many well-known side effects, including the increase of LDL
(“bad”) cholesterol and the
decrease of HDL (“good”) cholesterol. Other side effects reported with synthetic
progestins include bloating, breast soreness,
depression, and mood swings. Natural
progesterone has been shown to have no adverse effect on HDL cholesterol levels.6 Overall, natural
progesterone is considerably safer than progestins and is therefore preferred by many doctors
in situations where either would be effective.7
At the time of writing, there were no well-known drug interactions
with progesterone.
References:1. Araghiniknam M, Chung S, Nelson-White T, et al. Antioxidant activity
of dioscorea and dehydroepiandrosterone (DHEA) in older humans. Life Sci
1996;11:147–57.
2. Dollbaum CM. Lab analyses of salivary DHEA and progesterone following
ingestion of yam-containing products. Townsend Letter for Doctors and Patients: Oct
1995, 104.
3. Hargrove JT, Maxson WS, Wentz AC, et al. Menopausal hormone
replacement therapy with continuous daily oral micronized estradiol and progesterone.
Obstet Gynecol 1989;73:606–12.
4. Hargrove JT, Osteen KG. An alternative method of hormone replacement
therapy using the natural sex steroids. Infert Repro Med Clin N Am
1995;6:653–74.
5. Cooper A, Spencer C, Whitehead MI, et al. Systemic absorption of
progesterone from Progest cream in postmenopausal women. Lancet
1998;351:1255–56 [letter] and Lancet 1998;352:905–6 [comments].
6. Ottosson UB, Johansson BG, von Schoultz B. Subfractions of
high-density lipoprotein cholesterol during estrogen replacement therapy: a comparison between
progestogens and natural progesterone. Am J Obstet Gynecol.
1985;151:746–50.
7. Hargrove JT, Osteen KG. An alternative method of hormone replacement
therapy using the natural sex steroids. Infert Repro Med Clin N Am
1995;6:653–74.