Natural Estrogen Replacement: Do Over-the-Counter Supplements Work?

What is natural estrogen replacement?

People searching for natural estrogen replacement usually want one of two things. Some want an over-the-counter supplement that can stand in for the estrogen their ovaries no longer make. Others want a prescription estrogen that is as close as possible to their own. These are very different products.

• Plant estrogens (phytoestrogens) are compounds in foods such as soy and red clover with a structure loosely resembling estrogen. They bind weakly to estrogen receptors. They are sold as dietary supplements.
• Bioidentical estradiol is the same molecule as the main estrogen your ovaries made before menopause. It is made in a lab, requires a prescription, and comes in FDA-approved patches, gels, sprays, tablets and vaginal products.

Only the second one actually replaces estrogen. This guide focuses on the first, because that is where most of the confusion lies. For the broader picture of “natural” hormone therapy, including progesterone and compounded hormones, see our guide to natural hormone replacement therapy.

Are there natural estrogen supplements over the counter?

There are plenty of products marketed that way, but none contain human estrogen. The main ingredients you will see are:

These products are sold as dietary supplements. Unlike drugs, supplements are not approved by the FDA before they are sold, and manufacturers are responsible for their own safety and labeling (NCCIH). Dose and purity can vary between brands.

Does soy work as a natural estrogen replacement?

Soy is the most studied option, and the results are mixed. A 2012 meta-analysis of 17 placebo-controlled trials found that soy isoflavone supplements (median dose 54 mg a day) reduced hot flash frequency by about 21% and severity by about 26% more than placebo, with large differences between studies (Taku 2012). A 2016 JAMA review of plant-based therapies found phytoestrogens were linked to about 1.3 fewer hot flashes a day and slightly less vaginal dryness, but no change in night sweats. It also noted that about three-quarters of the trials had a high risk of bias in three or more areas (Franco 2016).

The Cochrane review, which looked at 43 trials and 4,364 women, was more cautious. It found no conclusive evidence that phytoestrogen supplements reduce hot flashes or night sweats, though extracts with high levels of genistein (over 30 mg a day) deserve more study. It also found a strong placebo effect, with hot flashes falling by up to 59% on placebo alone (Lethaby 2013).

The NIH summarizes it this way: soy may help reduce hot flashes, but the effect may be small and results have not been consistent (NCCIH, Soy). The Menopause Society does not recommend soy foods, soy extracts or the soy metabolite equol for hot flashes (Menopause Society 2023).

What about red clover?

Red clover contains isoflavones similar to soy's. In the Cochrane review, five trials of a red clover extract pooled together showed no significant difference from placebo in daily hot flashes (Lethaby 2013). In a 12-month randomized trial, hot flashes and night sweats fell by 57% with red clover and 63% with placebo, compared with 94% on hormone therapy; only hormone therapy beat placebo (Geller 2009). The NIH describes the results as inconsistent, with some studies at high risk of bias (NCCIH, Red Clover).

By the numbers

Drop in hot flashes and night sweats over 12 months

57%with red cloverSource: Geller 2009

63%with placeboSource: Geller 2009

94%with hormone therapy, the only option that beat placeboSource: Geller 2009

Is black cohosh a natural estrogen?

No, even though it is often sold on the same shelf. Black cohosh is a root from the buttercup family. The NIH Office of Dietary Supplements says its active ingredients and mechanism are unknown, and studies disagree on whether it affects estrogen levels at all. Some researchers think it may act on brain pathways such as serotonin instead (ODS).

The evidence for symptoms is weak. A Cochrane review of 16 trials and 2,027 women found no significant difference between black cohosh and placebo in hot flash frequency and concluded there is insufficient evidence to support its use (Leach 2012). In the 12-month trial above, hot flashes and night sweats fell by 34% with black cohosh, less than with placebo (Geller 2009). A later NIH summary notes that a 2023 review of black cohosh products, alone or with other herbs, found possible benefit for overall symptoms, so the picture is still unsettled (NCCIH, Black Cohosh).

What are the risks of natural estrogen supplements?

• Liver injury with black cohosh. Rare cases of liver damage, some very serious, have been reported in people taking products labeled black cohosh. It isn't certain the herb caused them; some products were found to contain the wrong herb. Stop and see a clinician if you develop dark urine, yellowing skin or unusual fatigue (NCCIH).
• Hormone-sensitive conditions. It is uncertain whether black cohosh is safe after breast or uterine cancer. Soy supplements have not been shown to lower breast cancer risk (NCCIH). If you have a history of an estrogen-sensitive cancer, talk to your oncology team before taking any of these.
• Interactions. Soy foods high in tyramine can interact dangerously with MAO inhibitor antidepressants, and herbs can interact with other medicines (NCCIH).
• Side effects. Soy can cause bloating, constipation, diarrhea or nausea. Studies have used concentrated soy isoflavones safely for up to 6 months and red clover extracts for up to 2 years.
• Delay. The less obvious risk is spending months on something with weak evidence while sleep, mood and quality of life suffer.

When does prescription estradiol make sense?

If supplements haven't helped, or your symptoms are significantly affecting your sleep, work or relationships, prescription estrogen is worth discussing. Hormone therapy is the most effective treatment for hot flashes and night sweats and for vaginal and urinary symptoms of menopause, and it prevents bone loss. For women under 60 or within 10 years of menopause with no contraindications, The Menopause Society considers the benefit-risk balance favorable (Menopause Society 2022).

A few points to know:

• Estradiol is bioidentical. If “natural” matters to you, estradiol is the same molecule your body made. It is available in FDA-approved patches, gels, sprays and tablets.
• If you have a uterus, you need progesterone too. Estrogen alone thickens the uterine lining and raises the risk of endometrial cancer.
• For vaginal dryness only, low-dose vaginal estrogen works locally with very little absorption. See our guide to local vs. systemic HRT.
• Estrogen isn't for everyone. A history of breast cancer, blood clots, stroke, heart disease or unexplained bleeding usually rules out systemic estrogen. A clinician needs your full history.

Amie's prescription is Amie HRT+, a compounded cream containing estradiol and progesterone, with the strength chosen by a licensed clinician after an online review. It is not FDA-approved. The clinician decides whether it is appropriate, and FDA-approved estradiol and progesterone from your own doctor are a well-studied alternative.

How do you know if you have low estrogen?

Hot flashes, night sweats, vaginal dryness, poor sleep and irregular periods in your 40s or 50s are the classic signs. Blood tests are often unhelpful in perimenopause because estrogen swings from week to week. Our guide to low estrogen symptoms covers the signs by body system and when testing is useful, and estrogen levels by age explains what normal looks like.

The bottom line