Our proprietary “Star-Rating” system was developed to help you easily understand the amount of scientific support behind each supplement in relation to a specific health condition. While there is no way to predict whether a vitamin, mineral, or herb will successfully treat or prevent associated health conditions, our unique ratings tell you how well these supplements are understood by the medical community, and whether studies have found them to be effective for other people.
For over a decade, our team has combed through thousands of research articles published in reputable journals. To help you make educated decisions, and to better understand controversial or confusing supplements, our medical experts have digested the science into these three easy-to-follow ratings. We hope this provides you with a helpful resource to make informed decisions towards your health and well-being.
3 Stars Reliable and relatively consistent scientific data showing a substantial health benefit.
2 Stars Contradictory, insufficient, or preliminary studies suggesting a health benefit or minimal health benefit.
1 Star For an herb, supported by traditional use but minimal or no scientific evidence. For a supplement, little scientific support.
Consult a qualified healthcare practitioner
The oral, micronized form has been shown to successfully induce normal menstrual bleeding in women with secondary amenorrhea. (Use of this natural hormone should always be supervised by a doctor.)
Oral, micronized progesterone (200 to300 mg per day) has been shown in at least one double-blind trial to successfully induce normal menstrual bleeding in women with secondary amenorrhea.1 Use of this natural hormone should always be supervised by a doctor.
Apply enough topical cream to provide 20 mg of the supplement to the skin daily
Progesterone, either natural or synthetic, has been linked to improved hot flashes, anxiety, depression, sleep problems, and sexual functioning, and quality of life.
Natural progesterone supplementation has been anecdotally linked to reduction in symptoms of menopause.2 , 3 , 4 In one trial, natural progesterone was found to have no independent effect on symptoms, and synthetic progestins were found to increase breast tenderness.5 However, a double-blind trial found that topical administration of natural progesterone cream led to a reduction in hot flashes in 83% of women, compared with improvement in only 19% of those given placebo.6 Preliminary research has found that oral, micronized progesterone therapy is associated with improved quality of life among postmenopausal women. However, oral micronized progesterone is available only by prescription in the United States.7 Hot flashes, anxiety, depression, sleep problems, and sexual functioning were among the symptoms improved in a majority of women surveyed. Synthetic progestins, also available only by prescription, have reduced symptoms of menopause.8 , 9 , 10
Progesterone is a hormone and, as such, concerns about its inappropriate use (i.e., as an over-the-counter supplement) have been raised. The amount of progesterone in commercially available creams varies widely, and the progesterone content is not listed on the label because the creams are legally regulated as cosmetics, not dietary supplements. Therefore, a physician should be consulted before using these hormone-containing creams as supplements. Although few side effects have been associated with topical progesterone creams, skin reactions may occur in some users. Effects of natural progesterone on breast cancer risk remain unclear; research has suggested both increased and reduced risk.
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Preliminary evidence suggests that progesterone might reduce osteoporosis risk by promoting bone density.
Preliminary evidence suggests that progesterone might reduce the risk of osteoporosis.11 A preliminary trial using topically applied natural progesterone cream in combination with dietary changes, exercise, vitamin and calcium supplementation, and estrogen therapy reported large gains in bone density over a three-year period in a small group of postmenopausal women, but no comparison was made to examine the effect of using the same protocol without progesterone.12 Other trials have reported that adding natural progesterone to estrogen therapy did not improve the bone-sparing effects of estrogen and that progesterone applied topically every day for a year did not reduce bone loss.13 14 In a more recent double-blind study, however, progesterone had a modest bone-sparing effect in post-menopausal women.15
Refer to label instructions
Some practitioners report success using topical progesterone cream for dysmenorrhea.
Some practitioners report success using topical progesterone cream for dysmenorrhea.16 To date, this approach lacks sufficient research.
Refer to label instructions
Anecdotal reports suggest that progesterone may be effective against PMS symptoms.
Most well-controlled trials have not found vaginally applied natural progesterone to be effective against the symptoms of premenstrual syndrome.17 Only anecdotal reports have claimed that orally or rectally administered progesterone may be effective.18 Progesterone is a hormone, and as such, there are concerns about its inappropriate use. A physician should be consulted before using this or other hormones. Few side effects have been associated with use of topical progesterone creams, but skin reactions may occur. The effect of natural progesterone on breast cancer risk remains unclear; some research suggests the possibility of increased risk, whereas other research points to a possible reduction in risk.
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.19 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.20 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.
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.21 , 22 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.
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.23
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.24 Overall, natural progesterone is considerably safer than progestins and is therefore preferred by many doctors in situations where either would be effective.25
1. Shangold MM, Tomai TP, Cook JD, et al. Factors associated with withdrawal bleeding after administration of oral micronized progesterone in women with secondary amenorrhea. Fertil Steril 1991;56:1040–7.
2. Lee JR. Natural Progesterone. The multiple roles of a remarkable hormone. Sebastipol, CA: BLL Publishing, 1993, 31–7.
3. Gaby AR. Commentary. Nutr Healing 1996;June:1,10–1.
4. Wright JV. Hormones for menopause. Nutr Healing 1996;June:1–2,9.
5. Greendale GA, Reboussin BA, Hogan P, et al. Symptom relief and side effects of postmenopausal hormones: results from the Postmenopausal Estrogen/Progestin Interventions Trial. Obstet Gynecol 1998;92:982–8.
6. Leonetti HB, Long S, Anasti JM. Transdermal progesterone cream for vasomotor symptoms and postmenopausal bone loss. Obstet Gynecol 1999;94:225–8.
7. Fitzpatrick LA, Pace C, Wiita B. Comparison of regimens containing oral micronized progesterone or medroxyprogesterone acetate on quality of life in postmenopausal women: a cross-sectional survey. J Women’s Health Gender-Based Med 2000;9:381–7.
8. Bullock JL, Massey FM, Gambrell RD Jr. Use of medroxyprogesterone acetate to prevent menopausal symptoms. Obstet Gynecol 1975;46:165–8.
9. Morrison JC, Martin DC, Blair RA, et al. The use of medroxyprogesterone acetate for relief of climateric symptoms. Am J Obstet Gynecol 1980 138:99–104.
10. Schiff I, Tulchinsky D, Cramer D, Ryan KJ. Oral medroxyprogesterone in the treatment of postmenopausal symptoms. JAMA 1980;244:1443–5.
11. Prior JC. Progesterone as a bone-trophic hormone. Endocr Rev 1990;11:386–98.
12. Lee JR. Osteoporosis reversal: the role of progesterone. Int Clin Nutr Rev 1990;10:384–91.
13. Riis BJ, Thomsen K, Strom V, Christiansen C. The effect of percutaneous estradiol and natural progesterone on postmenopausal bone loss. Am J Obstet Gynecol 1987;156:61–5.
14. Leonetti HB, Longo S, Anasti JM. Transdermal progesterone cream for vasomotor symptoms and postmenopausal bone loss. Obstet Gynecol 1999;94:225–8.
15. Lydeking-Olsen E, Beck-Jensen JE, Setchell KD, Holm-Jensen T. Soymilk or progesterone for prevention of bone loss: a 2 year randomized, placebo-controlled trial. Eur J Nutr 2004;43:246–57.
16. Hudson T. Natural progesterone: Clinical indications in women’s health. Townsend Letter for Doctors and Patients 1999;Dec:140–3.
17. Freeman E, Rickels K, Sondheimer SJ, Polansky M. Ineffectiveness of progesterone suppository treatment for premenstrual syndrome. JAMA 1990;264:349–53.
18. Martorano JT, Ahlgrimm M, Colbert T. Differentiating between natural progesterone and synthetic progestins: clinical implications for premenstrual syndrome and perimenopause management. Comp Ther 1998;24:336–9.
19. 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.
20. 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].
21. 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.
22. Dollbaum CM. Lab analyses of salivary DHEA and progesterone following ingestion of yam-containing products. Townsend Letter for Doctors and Patients: Oct 1995, 104.
23. 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.
24. 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.
25. 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.
Last Review: 05-01-2013
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The information presented in Aisle7 is for informational purposes only. It is based on scientific studies (human, animal, or in vitro), clinical experience, or traditional usage as cited in each article. The results reported may not necessarily occur in all individuals. For many of the conditions discussed, treatment with prescription or over the counter medication is also available. Consult your doctor, practitioner, and/or pharmacist for any health problem and before using any supplements or before making any changes in prescribed medications. Information expires June 2014.
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