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Red Clover herb extract

Also known as: Red Clover, Red Clover Extract, Trifolium pratense

Overview

Red clover (*Trifolium pratense*) is a flowering plant in the legume family, known for its potential health benefits derived from its isoflavone content. These isoflavones, including biochanin A, formononetin, daidzein, and genistein, are phytoestrogens that mimic estrogen in the body. Red clover extracts are primarily used to alleviate menopausal symptoms, particularly hot flashes, and are also being investigated for cardiovascular benefits. The evidence supporting its efficacy is considered moderate, with numerous randomized controlled trials and meta-analyses available, although heterogeneity among studies exists. Red clover is available in various forms, including capsules, tablets, and teas, with standardized extracts containing a consistent percentage of isoflavones being the preferred choice for supplementation. It is sourced from the red clover plant itself, with extraction processes concentrating the beneficial isoflavones.

Benefits

The primary benefit of red clover extract lies in its ability to reduce hot flashes, particularly in postmenopausal women experiencing five or more hot flashes per day. A meta-analysis of eight trials indicated a weighted mean difference of -1.73 hot flashes per day with red clover supplementation, especially when using dosages of 80mg or more of isoflavones daily for at least 12 weeks. Secondary benefits include potential improvement in vaginal dryness, although the evidence is less consistent. Some studies suggest that red clover may also modulate lipid profiles, but findings have been mixed, with a 2018 review noting inconsistent effects on LDL cholesterol levels. Overall, the strength of evidence for hot flash reduction is moderate, while evidence for other benefits is weaker.

How it works

Red clover's mechanism of action primarily involves the modulation of estrogen receptors, particularly through selective agonism of ERβ receptors by isoflavones like biochanin A and formononetin. This interaction can help regulate vasomotor symptoms associated with menopause. Additionally, red clover may influence vasomotor regulation through interactions with serotonin pathways. The bioavailability of red clover isoflavones is affected by glucuronidation and sulfation in the gut, as well as interindividual variations in equol production, a metabolite of daidzein. Peak plasma concentrations of isoflavones typically occur 6-8 hours post-ingestion.

Side effects

Common side effects of red clover extract include gastrointestinal discomfort (5-8%) and headaches (3-5%). Less common side effects may include rash and myalgia. Although rare, there are theoretical concerns regarding estrogen-sensitive cancers due to the phytoestrogenic nature of red clover isoflavones. Red clover is contraindicated in individuals with hormone-sensitive cancers, during pregnancy due to its potential uterine stimulant effects, and in those using concomitant anticoagulant medications. Caution is advised in individuals with a high risk of estrogen-sensitive cancers. Long-term safety data remains limited, necessitating careful consideration of potential risks and benefits before prolonged use.

Dosage

The minimum effective dosage of red clover extract is 40mg of isoflavones per day, with an optimal range of 80-160mg of isoflavones per day for managing menopausal symptoms. A maximum safe dosage of 300mg per day is recommended for short-term use. Standardized extracts containing 40% isoflavones are preferred to ensure consistent dosing. It is recommended to divide the daily dosage into multiple doses taken with meals to enhance absorption. The duration of treatment should be at least 12 weeks to observe significant effects on hot flash reduction. Individuals should consult with a healthcare professional to determine the appropriate dosage and duration of use based on their specific health needs and conditions.

FAQs

How long until results appear?

Significant reduction in hot flashes typically occurs after 12 weeks of consistent use at an appropriate dosage.

Is red clover better than soy isoflavones?

Red clover and soy isoflavones have comparable efficacy but differ in their isoflavone ratios, with red clover containing higher levels of biochanin A.

Does red clover increase cancer risk?

There is no direct evidence that red clover increases cancer risk, but caution is advised in individuals with a high risk of estrogen-sensitive cancers.

Research Sources

https://pubmed.ncbi.nlm.nih.gov/33920485/ – A 2021 meta-analysis of 8 RCTs (n=1,027) found that red clover significantly reduced hot flashes (WMD -1.73/day). However, the analysis also noted high heterogeneity (I²=87.34%), suggesting variability in the study populations and methodologies. The study met Cochrane criteria and was assessed as having a moderate risk of bias.
https://jamanetwork.com/journals/jama/fullarticle/2529629 – A 2016 systematic review of 62 RCTs found that red clover showed moderate efficacy compared to placebo in alleviating menopausal symptoms. The review highlighted the challenge of inconsistent outcome measures across studies, contributing to high heterogeneity. The review was PRISMA-compliant but noted the need for more standardized research approaches.
https://www.mdpi.com/1661-3821/4/3/26 – This study investigates the estrogenic activity of red clover isoflavones. It highlights the potential of these compounds to selectively bind to estrogen receptors, offering a targeted approach to hormone-related health concerns.
https://www.verywellhealth.com/the-benefits-of-red-clover-89577 – This article provides an overview of the potential health benefits of red clover, including its use for menopausal symptoms and bone health. It emphasizes the importance of consulting with a healthcare provider before using red clover supplements.
https://www.mountsinai.org/health-library/herb/red-clover – This resource from Mount Sinai discusses the traditional uses of red clover and its potential benefits for various health conditions. It also outlines potential side effects and interactions, advising caution and consultation with a healthcare professional.