Multi-faceted Trifolium pratense may have weak anti-estrogen activity that is suggested to maintain T.
A longstanding traditional herbal remedy, red clover is sometimes included in testosterone booster complexes. While evidence supporting its use for testosterone is early and conflicted, some researchers and supplement formulators have theorized red clover might help T levels by:
- Reducing prostate specific antigen levels. Higher amounts of PSA are linked to testosterone deficiency and general prostate issues.
- Lowering rate of testosterone conversion. Red clover has been suggested to work against enzymes that alter testosterone in the bloodstream.
- Helping to preserve the “T-Helper” luteinizing hormone. LH stimulates the production of testosterone via Leydig cells.
- How Red Clover Might (or Might Not) Help With T
- Red Clover in Hormone-Related Supplements
- Dosage for Testosterone
- Side Effects
- Available Forms of Red Clover
- Supplements in Review Recommendation
Red clover is a member of the bean family, with early descriptions using it as a main food source for cattle. Medieval Christians associated the three leaves as a resemblance to the Holy Trinity and sought to use it in many aspects of diet and additives. The herb was first utilized in 1917 as a blood purifier and amplified in the 1930s as a supposed anti-tumor remedy, in which its beneficial effects are still in popular use today.
Trifolium pratense contains coumarin, which is a natural organic molecule that is used in dyes, perfumes, and to help with asthma. It also contains compounds called isoflavones, which have antioxidant and phytoestrogenic actions.
These isoflavones have been suggested to regulate estrogen levels — which in turn affect testosterone — and are believed to be the “active ingredients” behind red clover’s potential T benefits. In theory, a reduction of female sex hormones such as estrogen would in turn increase the ratio of testosterone in the bloodstream.
How Red Clover Might (or Might Not) Help With T
May help maintain levels of luteinizing hormone
The effects of taking red clover are shown to increase LH when compared to control groups.1 This hormone acts upon Leydig cells of testis which in turn produce testosterone. Unfortunately, this mechanism of action has seen little research.
May raise amount of liver transaminase
Yransaminase is an enzyme involved in converting molecules for energy and manipulating amino acids for use in the body. High levels of transaminase are associated with exercise and heavy workouts,2 but can also indicate liver problems. Research suggests that consumption of red clover isoflavone can nearly double transaminase levels, while keeping them within healthy limits.3
Although liver enzymes do not directly affect testosterone levels, they may be correlated with increases in vitality and similar health benefits as an increase in testosterone.
Acting as an anti-estrogen supplement to reduce estradiol
Estradiol is classified as a bodily steroid and estrogen sex hormone that maintains female and male reproduction. When taken in regular intervals, consumption of red clover has been linked to an overall decrease in estradiol and similar hormones. This could — in theory — have a pro-testosterone effect for male sexual vitality.4
Seems to reduce conversion rate of testosterone to DHT
Dihydrotestosterone is a vital hormone for developing males, but is reported to contribute to baldness in later years. It is directly converted from testosterone, so a decrease of DHT levels is, in theory, immediately related to increases of testosterone. Isoflavones, the pronounced ingredient of red clover, has been shown to reduce conversion rates and lower DHT levels within the bloodstream.5 This mechanism is achieved by 5-α-reductase, an enzyme located throughout the body such as the prostate, skin, and liver. Publications concerning this aspect are few and far between, and the studies that do exist are minuscule. The narrow field of view should be taken into account when judging this beneficial factor.
Like other phytoestrogen nutrients, red clover is more popular as a women’s menopause supplement than a men’s testosterone supplement. This traces back to evidence showing that in pre-menopausal women, phytoestrogens seem to have an anti-estrogen effect; while in post-menopausal women, they seem to have a pro-estrogen effect.
Red clover is included in some Testosterone Booster formulas because of its “anti-estrogen” activity, which in theory would shift the balance towards T. It also appears to have prostate-protective effects that may reflect healthier testosterone levels. But overall, red clover’s reputation as a women’s supplement and unsteady evidence seem to position it as more of a “wildcard” testosterone supplement.
Applying red clover to dedicated animal experiments seems to be an ongoing process. Current research seems to support some theories that red clover might:
- Increases total androgen amounts when compared to mice not given any dosage.6
- Stimulates estrogen receptor production which works against tumor formation in the prostate.7
- Slightly increases estrogen production measured by uterine weight in mice.8
- Lowers prostate size in mice which lowers risks of medical conditions and maintains a comfortable internal groin.9
While the first research article pointed out some promising results for the production of testosterone, the following three are what remain of limited relevant data. Two of the studies point towards an estrogen-oriented benefit, which does not support the idea of a male-benefiting herb. The final study solely benefits males, but does not necessarily affect levels of testosterone.
Human research seems to be much more prominent than animal works, studying women much more than men for the benefits of adjusting hormones in post-menopause. Two medicinal trials stood out as irrefutable sources of observation:
A smaller study in 2007 gave men aged 40-75 whom had family history of colon problems 84 mg of isoflavone, a pronounced ingredient in red clover. This was done over the course of two months with frequent intervals of study, such as colonoscopies. Others of the same category were given a placebo in order to contrast measured differences in insulin-like growth factors. IGF proteins are commonly associated with testosterone hormones, as both act towards similar physiological goals and operate under comparable time frames. This makes testosterone and IGF easy to compare, as both are commonly considered to always act in a complex relationship.11
- The researchers concluded that “isolated isoflavones did not influence serum IGF-I concentrations in our adequately powered, randomized, placebo-controlled, double-blind crossover trial.” However small a study may present, it is impossible to overlook the testosterone-related benefits that may have been supported with a successful experiment reaction.12
The majority of trials assessed had a duration of 2-3 months, with the shortest lasting 1 week and the longest 4 years. Archives such as PubMed and CAB Abstracts were searched to find relevant data on the effects of red clover when taken under professional supervision and observation. Amounts given ranged from less than 10 mg daily to more than 150 mg daily in isoflavone intake, and the age of participants was between 21 years and 74 years of age. Those engaging in the trial with prostate concerns roughly equaled those who had none. Using statistical analysis several models were made to compare results from across the board.
- After all data had been accounted for it was surmised “neither soy protein nor isoflavones affect reproductive hormone concentrations in men regardless of age or cancer status.” Of course, the research involved had miniscule fluctuations in results but these were deemed insignificant due to their small affecting size or the specific nature of the trial.13
43 women aged 61-75 whom were all postmenopausal were given 40 or 80 mg of phytoestrogen daily to compare with sex hormone-binding globulin (SHBG) levels in the bloodstream. SHBG proteins bind to testosterone and other sex hormones and render them useless, so controlling their numbers may prove to assist in adjusting overall sex hormone quantity.
- It was easily summarized that “we did not see any effect of red clover based phytoestrogens on SHBG, oestradiol or testosterone levels in this study.”14
20 men aged approximately 65 were given a daily dose of isoflavone extract to study effects. As previously discussed, an increase of transaminases can indicate increased levels of excersise, or possibly liver issues. High amounts of PSA are correlated with prostate issues in aging men.
- The scientists concluded that “The most important finding was a significant reduction of 33% in the PSA levels.”
A statistical model was used to assess levels of testosterone, SHGB, and other related hormones after women in the study had taken red clover supplements. For testosterone, three previous studies were assessed for data on menopausal women which showed testosterone levels increasing slightly but significantly. When amounts of SHBG were measured during research trials, all four trials that were analyzed showed a total decrease in SHGB.
- It was stated that “red clover may increase testosterone levels” and that “to sum up, red clover may slightly decrease SHBG levels.“15
Three of the previous studies seem to state similar rejections of red clover’s proposed testosterone benefits. However, the meta analysis focused on women had hopeful summaries along with the research showing a strong claim for the increased prostate protection. All in all, testosterone’s benefits do not seem to come through in these studies. The size of these findings are quite varied, but their results are thorough and unmistakable.
Dosage for Testosterone
- 40-160 mg daily in extracted form and in combination with other supplements
- 40-80 mg daily used in clinical research related to hormonal balance.
The majority of research agrees that red clover is indeed safe for consumption within limits. With other medications, red clover is known to alter the rate at which these drugs are broken down within the liver.16 Few have reported symptoms such as muscle ache, nausea, or rash-like reactions, but this may be related to exceeding the recommended dose amount.
Available Forms of Red Clover
Traditional methods of red clover have been through ointments on wounds or drying and adding with tea or medicine. In present times, oral consumption reigns as the most common form:
- Plain Red Clover. Labeled as purely stem, leaf, and flower, this is the most simple form. Taken as capsule or purchased in dried condition.
- Red Clover Extract. Mainly sold in liquid form, these are processed nutrients that may have lower bioactivity due to the exceedingly higher amount per serving.
- Natural Plant Form. Red clover is seen as an annoying weed in many regions in which it grows naturally. Thus obtaining it through personal research or a local gardening store will allow for exact manipulation to suit any possible nutritional needs.
- Isolated Nutrients. Many companies advertise for a gauranteed amount of active ingredients such as isoflavones or phytoestrogen. While much more packed with related vitamins, these capsules can be more expensive and should be bought from a trusted supplier.
Supplements in Review Recommendation
- Red Clover, 50-70 mg daily
Research on red clover for testosterone seems to constantly disagree. Results are variant at best, with some advocating for its androgen-boosting abilities and others for pro-estrogen outcomes. There are few risks in attempting to utilize the plant, and it has shown to be effective in other regions of health, but to solely ingest red clover for testosterone improvement is an unpredictable venture.
50-70 mg daily in nutrient isolated form should be enough to get an idea if Red Clover helps. While most research falls between a daily intake of 40-80 mg, this is done under the supervision of licensed professionals. There are better Anti-Estrogen T-boosters to explore, backed by more evidence than Red Clover.
- Huber, J et al. Effects of Soy Protein and Isoflavones on Circulating Hormone Concentrations in Pre- and Post-menopausal Women: A Systematic Review and Meta-analysis. Human Reproduction Update 16.1 (2009): 110-11. ↩
- Pettersson et al. Muscular Exercise Can Cause Highly Pathological Liver Function Tests in Healthy Men. British Journal of Clinical Pharmacology Br J Clin Pharmacol 65.2 (2008): 253-59 ↩
- Engelhardt, Paul F et al. Effects of One-Year Treatment with Isoflavone Extract from Red Clover on Prostate, Liver Function, Sexual Function, and Quality of Life in Men with Elevated PSA Levels and Negative Prostate Biopsy Findings. Urology 71.2 (2008): 185-90. ↩
- Duncan, A. M et al. Modest Hormonal Effects of Soy Isoflavones in Postmenopausal Women. Journal of Clinical Endocrinology & Metabolism 84.10 (1999): 3479-484. ↩
- Yi et al. Regulation of Male Sex Hormone Levels by Soy Isoflavones in Rats. Nutrition and Cancer 42.2 (2002): 206-10. ↩
- Jarred et al. Anti-androgenic Action by Red Clover-derived Dietary Isoflavones Reduces Non-malignant Prostate Enlargement in Aromatase Knockout (arko) Mice. The Prostate Prostate 56.1 (2003): 54-64. ↩
- Slater, M et al. In the Prostatic Epithelium, Dietary Isoflavones from Red Clover Significantly Increase Estrogen Receptor β and E-cadherin Expression but Decrease Transforming Growth Factor β1. Prostate Cancer Prostatic Dis Prostate Cancer and Prostatic Diseases 5.1 (2002): 16-21. ↩
- Mu, H et al. Research on Antioxidant Effects and Estrogenic Effect of Formononetin from Trifolium Pratense (red Clover). Phytomedicine 16.4 (2009): 314-19. ↩
- Risbridger, G et al. The in Vivo Effect of Red Clover Diet on Ventral Prostate Growth in Adult Male Mice. Reprod Fertil Dev 13.4 (2001): 325-29. ↩
- Thorup et al. Intake of Novel Red Clover Supplementation for 12 Weeks Improves Bone Status in Healthy Menopausal Women. Evidence-Based Complementary and Alternative Medicine 2015 (2015): 1-11. ↩
- Ashton, S et al. Testosterone Increases Insulin-like Growth Factor-1 and Insulin-like Growth Factor-binding Protein. Ann Clin Lab Sci 25.5 (1995): 381-88. ↩
- Vrieling, Alina et al. Isolated Isoflavones Do Not Affect the Circulating Insulin-Like Growth Factor System in Men at Increased Colorectal Cancer Risk. J. Nutr. 137.2 (2007): 379-83. ↩
- Hamilton-Reeves, J. “Clinical Studies Show No Effects of Soy Protein or Isoflavones on Reproductive Hormones in Men: Results of a Meta-analysis.” Fertil Steril 94.3 (2010): 997-1007. ↩
- Lee, C et al. Effect of Oral Phytoestrogen on Androgenicity and Insulin Sensitivity in Postmenopausal Women. Diabetes, Obesity and Metabolism 14.4 (2011): 315-19. ↩
- Ghazanfarpour, M et al. Red Clover for Treatment of Hot Flashes and Menopausal Symptoms: A Systematic Review and Meta-analysis. Journal of Obstetrics and Gynaecology 36.3 (2015): 301-11. ↩
- Unger et al. Simultaneous Determination of the Inhibitory Potency of Herbal Extracts on the Activity of Six Major Cytochrome P450 Enzymes Using Liquid Chromatography/mass Spectrometry and Automated Online Extraction. Rapid Communications in Mass Spectrometry Rapid Commun. Mass Spectrom. 18.19 (2004): 2273-281. ↩