Known as the female hormone, 'Estrogen' is a group of compounds that tends to work in opposition to androgens (like testosterone) and mediate fat metabolism, cognition, blood flow, and female reproduction. Men sometimes wish to lower estrogen via aromatase inhibition.

This page features 69 unique references to scientific papers.

Research analysis by and verified by the Research Team. Last updated on Apr 29, 2017.

Frequently Asked Questions

Questions and answers regarding Estrogen

Q: Is soy good or bad for you?

A: Small amounts of soy to youth are neither good nor bad. Higher doses have their 'good or bad' properties, dependent on context.

Read full answer to "Is soy good or bad for you?"

Human Effect Matrix

The Human Effect Matrix looks at human studies (it excludes animal and in vitro studies) to tell you what supplements affect estrogen

Grade Level of Evidence
Robust research conducted with repeated double-blind clinical trials
Multiple studies where at least two are double-blind and placebo controlled
Single double-blind study or multiple cohort studies
Uncontrolled or observational studies only
Level of Evidence
? The amount of high quality evidence. The more evidence, the more we can trust the results.
Outcome Magnitude of effect
? The direction and size of the supplement's impact on each outcome. Some supplements can have an increasing effect, others have a decreasing effect, and others have no effect.
Consistency of research results
? Scientific research does not always agree. HIGH or VERY HIGH means that most of the scientific research agrees.
All comparative evidence is now gathered in our ​Supplement Goals Reference.
The evidence for each separate supplement is still freely available ​here.
Red Clover Extract  
7-Keto DHEA  
Black Cohosh  
D-Aspartic Acid  
Gamma Oryzanol  
Garcinia cambogia  
Green Tea Catechins  
Horny Goat Weed  
Panax ginseng  
Royal Jelly  
Vitamin K  
Grape Seed Extract  
Pueraria lobata  

Scientific Research

Skeletal Muscle and Hypertrophy


Both the alpha subset (ERα) and beta subset (ERβ) of the estrogen receptor are present in the skeletal muscle tissue of rats[1][2] and humans[3][4][5] of both sexes.

Estradiol is known to attenuate the rate of inflammatory processes following damaging exercise[6] (also seen in ischemia/reperfusion[7]) by reducing neutrophil accumulation, which is thought to explain the reduce rates of muscle tissue regeneration in ovarectomized rats (model of menopause) relative to those given estrogen[8][9] with similar effects in male rats[10] and is thought to explain the higher than average rates of sarcopenia observed in menopausal women relative to premenopausal women[11] which is alleviated with hormone replacement therapy.[12] This anti-inflammatory response does not appear to be mediated by either estrogen receptor.[13]

Treatment of male[14] and female[15] rats with estradiol results in increased muscle cell recruitment following damaging exercise by an estrogen receptor dependent mean[13] and particularly satellite cell recruitment is mediated through the alpha subset (ERα).[16]

Selective activation of the β subset (ERβ) results in muscle protein synthesis, as ablation of the receptor exacerbates damage from exercise while treatment with agonists causes satellite cell activation and proliferation;[17] Activation of ERβ appears to enhance IGF-1 related anabolic pathways.[17]

Both estrogen receptors and injections of estrogen (to reach a higher circulating level) are associated with increased recovery rates of skeletal muscle secondary to anti-inflammatory effects and increased satellite cell activation

Scientific Support & Reference Citations


  1. Milanesi L, Russo de Boland A, Boland R. Expression and localization of estrogen receptor alpha in the C2C12 murine skeletal muscle cell line. J Cell Biochem. (2008)
  2. Milanesi L, et al. Expression and subcellular distribution of native estrogen receptor beta in murine C2C12 cells and skeletal muscle tissue. Steroids. (2009)
  3. Wiik A, et al. Oestrogen receptor beta is expressed in adult human skeletal muscle both at the mRNA and protein level. Acta Physiol Scand. (2003)
  4. Wiik A, et al. Expression of both oestrogen receptor alpha and beta in human skeletal muscle tissue. Histochem Cell Biol. (2009)
  5. Wiik A, et al. Oestrogen receptor beta is present in both muscle fibres and endothelial cells within human skeletal muscle tissue. Histochem Cell Biol. (2005)
  6. Tiidus PM, et al. Estrogen effect on post-exercise skeletal muscle neutrophil infiltration and calpain activity. Can J Physiol Pharmacol. (2001)
  7. Stupka N, Tiidus PM. Effects of ovariectomy and estrogen on ischemia-reperfusion injury in hindlimbs of female rats. J Appl Physiol. (2001)
  8. Sitnick M, et al. Ovariectomy prevents the recovery of atrophied gastrocnemius skeletal muscle mass. J Appl Physiol. (2006)
  9. McClung JM, et al. Estrogen status and skeletal muscle recovery from disuse atrophy. J Appl Physiol. (2006)
  10. Sugiura T, et al. Estrogen administration attenuates immobilization-induced skeletal muscle atrophy in male rats. J Physiol Sci. (2006)
  11. Walsh MC, Hunter GR, Livingstone MB. Sarcopenia in premenopausal and postmenopausal women with osteopenia, osteoporosis and normal bone mineral density. Osteoporos Int. (2006)
  12. Sørensen MB, et al. Obesity and sarcopenia after menopause are reversed by sex hormone replacement therapy. Obes Res. (2001)
  13. Enns DL, Iqbal S, Tiidus PM. Oestrogen receptors mediate oestrogen-induced increases in post-exercise rat skeletal muscle satellite cells. Acta Physiol (Oxf). (2008)
  14. Tiidus PM, Deller M, Liu XL. Oestrogen influence on myogenic satellite cells following downhill running in male rats: a preliminary study. Acta Physiol Scand. (2005)
  15. Enns DL, Tiidus PM. Estrogen influences satellite cell activation and proliferation following downhill running in rats. J Appl Physiol. (2008)
  16. Thomas A, Bunyan K, Tiidus PM. Oestrogen receptor-alpha activation augments post-exercise myoblast proliferation. Acta Physiol (Oxf). (2010)
  17. Velders M, et al. Selective estrogen receptor-β activation stimulates skeletal muscle growth and regeneration. FASEB J. (2012)

Via HEM and FAQ:

  1. Dewell A, Hollenbeck PL, Hollenbeck CB. Clinical review: a critical evaluation of the role of soy protein and isoflavone supplementation in the control of plasma cholesterol concentrations. J Clin Endocrinol Metab. (2006)
  2. Genistein, daidzein, and their .beta.-glycoside conjugates: antitumor isoflavones in soybean foods from American and Asian diets.
  3. Shor D, et al. Does equol production determine soy endocrine effects. Eur J Nutr. (2012)
  4. el-Adawy TA, et al. Effect of soaking process on nutritional quality and protein solubility of some legume seeds. Nahrung. (2000)
  5. Barampama Z, Simard RE. Effects of soaking, cooking and fermentation on composition, in-vitro starch digestibility and nutritive value of common beans. Plant Foods Hum Nutr. (1995)
  6. O'Toole DK. Characteristics and use of okara, the soybean residue from soy milk production--a review. J Agric Food Chem. (1999)
  7. Vishwanathan KH, et al. Production of okara and soy protein concentrates using membrane technology. J Food Sci. (2011)
  8. Yuan S, et al. Elimination of trypsin inhibitor activity and beany flavor in soy milk by consecutive blanching and ultrahigh-temperature (UHT) processing. J Agric Food Chem. (2008)
  9. Kwok KC, Liang HH, Niranjan K. Optimizing conditions for thermal processes of soy milk. J Agric Food Chem. (2002)
  10. van der Ven C, Matser AM, van den Berg RW. Inactivation of soybean trypsin inhibitors and lipoxygenase by high-pressure processing. J Agric Food Chem. (2005)
  11. Lusas EW, Riaz MN. Soy protein products: processing and use. J Nutr. (1995)
  12. Zhang WN, Liu DC. A new process for preparation of soybean protein concentrate with hexane-aqueous ethanol mixed solvents. J AOAC Int. (2005)
  13. Anderson RL, Wolf WJ. Compositional changes in trypsin inhibitors, phytic acid, saponins and isoflavones related to soybean processing. J Nutr. (1995)
  14. Isoflavone Content in Commercial Soybean Foods.
  15. Kreijkamp-Kaspers S, et al. Effect of soy protein containing isoflavones on cognitive function, bone mineral density, and plasma lipids in postmenopausal women: a randomized controlled trial. JAMA. (2004)
  16. Carroll KK. Review of clinical studies on cholesterol-lowering response to soy protein. J Am Diet Assoc. (1991)
  17. Anderson JW, Johnstone BM, Cook-Newell ME. Meta-analysis of the effects of soy protein intake on serum lipids. N Engl J Med. (1995)
  18. Long-term intake of soy protein improves blood lipid profiles and increases mononuclear cell low-density-lipoprotein receptor messenger RNA in hypercholesterolemic, postmenopausal women.
  19. Potter SM, et al. Soy protein and isoflavones: their effects on blood lipids and bone density in postmenopausal women. Am J Clin Nutr. (1998)
  20. The effect of soy protein with or without isoflavones relative to milk protein on plasma lipids in hypercholesterolemic postmenopausal women.
  21. Crouse JR 3rd, et al. A randomized trial comparing the effect of casein with that of soy protein containing varying amounts of isoflavones on plasma concentrations of lipids and lipoproteins. Arch Intern Med. (1999)
  22. Washburn S, et al. Effect of soy protein supplementation on serum lipoproteins, blood pressure, and menopausal symptoms in perimenopausal women. Menopause. (1999)
  23. Scheiber MD, et al. Dietary inclusion of whole soy foods results in significant reductions in clinical risk factors for osteoporosis and cardiovascular disease in normal postmenopausal women. Menopause. (2001)
  24. Wangen KE, et al. Soy isoflavones improve plasma lipids in normocholesterolemic and mildly hypercholesterolemic postmenopausal women. Am J Clin Nutr. (2001)
  25. Effects of feeding 4 levels of soy protein for 3 and 6 wk on blood lipids and apolipoproteins in moderately hypercholesterolemic men.
  26. Isoflavones from Red Clover Improve Systemic Arterial Compliance But Not Plasma Lipids in Menopausal Women.
  27. Uesugi T, Fukui Y, Yamori Y. Beneficial effects of soybean isoflavone supplementation on bone metabolism and serum lipids in postmenopausal japanese women: a four-week study. J Am Coll Nutr. (2002)
  28. Samman S, et al. The effect of supplementation with isoflavones on plasma lipids and oxidisability of low density lipoprotein in premenopausal women. Atherosclerosis. (1999)
  29. The Effects of Soy-Derived Phytoestrogens on Serum Lipids and Lipoproteins in Moderately Hypercholesterolemic Postmenopausal Women.
  30. Supplementation with Isoflavonoid Phytoestrogens Does Not Alter Serum Lipid Concentrations: A Randomized Controlled Trial in Humans.
  31. Cuevas AM, et al. Isolated soy protein improves endothelial function in postmenopausal hypercholesterolemic women. Eur J Clin Nutr. (2003)
  32. Dietary Soy Has Both Beneficial and Potentially Adverse Cardiovascular Effects: A Placebo-Controlled Study in Men and Postmenopausal Women.
  33. Food labeling: health claims; soy protein and coronary artery disease.
  34. Messina M. Insights gained from 20 years of soy research. J Nutr. (2010)
  35. Matthan NR, et al. Effect of soy protein from differently processed products on cardiovascular disease risk factors and vascular endothelial function in hypercholesterolemic subjects. Am J Clin Nutr. (2007)
  36. Hedlund TE, Johannes WU, Miller GJ. Soy isoflavonoid equol modulates the growth of benign and malignant prostatic epithelial cells in vitro. Prostate. (2003)
  37. Yuan JP, Wang JH, Liu X. Metabolism of dietary soy isoflavones to equol by human intestinal microflora--implications for health. Mol Nutr Food Res. (2007)
  38. The Clinical Importance of the Metabolite Equol—A Clue to the Effectiveness of Soy and Its Isoflavones.
  39. Decroos K, et al. Isolation and characterisation of an equol-producing mixed microbial culture from a human faecal sample and its activity under gastrointestinal conditions. Arch Microbiol. (2005)
  40. Lovati MR, et al. Soy protein peptides regulate cholesterol homeostasis in Hep G2 cells. J Nutr. (2000)
  41. Maskarinec G, et al. Serum prostate-specific antigen but not testosterone levels decrease in a randomized soy intervention among men. Eur J Clin Nutr. (2006)
  42. Deibert P, et al. Soy protein based supplementation supports metabolic effects of resistance training in previously untrained middle aged males. Aging Male. (2011)
  43. Kalman D, et al. Effect of protein source and resistance training on body composition and sex hormones. J Int Soc Sports Nutr. (2007)
  44. Hamilton-Reeves JM, et al. Isoflavone-rich soy protein isolate suppresses androgen receptor expression without altering estrogen receptor-beta expression or serum hormonal profiles in men at high risk of prostate cancer. J Nutr. (2007)
  45. Messina M. Soybean isoflavone exposure does not have feminizing effects on men: a critical examination of the clinical evidence. Fertil Steril. (2010)
  46. Hamilton-Reeves JM, et al. Clinical studies show no effects of soy protein or isoflavones on reproductive hormones in men: results of a meta-analysis. Fertil Steril. (2010)
  47. Siepmann T, et al. Hypogonadism and erectile dysfunction associated with soy product consumption. Nutrition. (2011)
  48. Liu B, et al. }{Equol-producing phenotype and in relation to serum sex hormones among healthy adults in Beijing}. Wei Sheng Yan Jiu. (2011)
  49. Tanaka M, et al. Isoflavone supplements stimulated the production of serum equol and decreased the serum dihydrotestosterone levels in healthy male volunteers. Prostate Cancer Prostatic Dis. (2009)
  50. Goodin S, et al. Clinical and biological activity of soy protein powder supplementation in healthy male volunteers. Cancer Epidemiol Biomarkers Prev. (2007)
  51. Messina M, et al. Effect of soy protein on testosterone levels. Cancer Epidemiol Biomarkers Prev. (2007)
  52. Dillingham BL, et al. Soy protein isolates of varying isoflavone content exert minor effects on serum reproductive hormones in healthy young men. J Nutr. (2005)