Does Ashwagandha Increase Estrogen Levels?

Ashwagandha does appear to raise estradiol, the body’s primary form of estrogen, but only under specific circumstances. Clinical trials in perimenopausal and menopausal women have found statistically significant increases in serum estradiol after weeks of supplementation. In men, however, the same hormone stays put. The picture gets more complicated at the cellular level, where one of ashwagandha’s key compounds actually behaves like an anti-estrogen. Whether ashwagandha “increases estrogen” for you depends heavily on your sex, your hormonal baseline, and which part of the plant’s chemistry you’re looking at.

What the Trials Show in Women

The strongest evidence for ashwagandha raising estrogen comes from trials in women whose estrogen levels have already started to decline. A randomized, double-blind, placebo-controlled trial in perimenopausal women found that ashwagandha root extract produced a statistically significant increase in serum estradiol compared to placebo, alongside significant reductions in both FSH and LH, the pituitary hormones that rise when the ovaries produce less estrogen.¹ A more recent trial in menopausal women found the same pattern: the ashwagandha group saw improved estradiol and progesterone levels while the placebo group’s FSH and LH continued to rise, as you’d expect without intervention.²

Both trials linked these hormonal shifts to tangible improvements in quality of life. Women in the ashwagandha groups reported fewer hot flashes, better sleep, lower stress scores, and improved overall well-being. The estradiol increase wasn’t just a number on a lab report; it tracked with symptom relief the women could actually feel.

An important detail: these studies were conducted in women at or near menopause, when estrogen production from the ovaries is naturally declining. There are no comparable placebo-controlled trials showing that ashwagandha raises estradiol in younger, premenopausal women with already-normal hormone levels. The evidence for an estrogen boost is firmly rooted in the context of hormonal decline.

Why Estradiol Rises in These Women

Ashwagandha doesn’t contain estrogen or act like a classic phytoestrogen the way soy isoflavones do. Instead, the working theory centers on its well-documented ability to reduce cortisol, the body’s main stress hormone. Cortisol and reproductive hormones are regulated by overlapping brain circuits. Chronic stress elevates cortisol, and persistently high cortisol can suppress the signals from the hypothalamus and pituitary that tell the ovaries to produce estrogen. By dialing down cortisol, ashwagandha may allow the brain’s hormonal control centers to resume more normal signaling to the gonads.

A narrative review on ashwagandha and women’s hormones described this as modulation of both the stress axis and the reproductive axis, noting that normalization of gonadotropins (FSH and LH) and estradiol levels is potentially achievable through this dual pathway.³ The FSH and LH reductions seen in the clinical trials support this interpretation. When estradiol goes up, the pituitary stops sending as many urgent “produce more” signals, and FSH and LH come back down. This feedback loop working properly again is a sign that the hormonal system is rebalancing, not that estrogen is being pushed to abnormally high levels.

It’s worth stressing that this mechanism means ashwagandha isn’t flooding the body with estrogen the way hormone replacement therapy does. It’s more like removing a brake. If the ovaries still have some residual capacity to produce estrogen, as they often do in perimenopause, lowering cortisol-driven suppression may let that capacity express itself again. Once the ovaries have fully shut down in late postmenopause, there’s less residual capacity to unlock, and whether ashwagandha would still raise estradiol at that stage is not well studied.

What Happens in Men

The male data tells a very different story. A randomized, double-blind, placebo-controlled crossover study in aging, overweight men found that eight weeks of ashwagandha extract raised DHEA-S and testosterone but produced no significant change in estradiol compared to placebo.⁴ This is reassuring for men who worry that anything raising testosterone might also raise estrogen through aromatization, the enzyme process that converts testosterone into estradiol. At least in this trial, that didn’t happen.

The review literature echoes this sex-specific pattern. Ashwagandha’s impact on androgens appears to differ between men and women: it tends to raise testosterone in men without raising estrogen, and it does not appear to elevate testosterone in women, unlike in male study groups.³ The herb seems to nudge each sex’s hormones back toward their respective norms rather than pushing all hormones in one direction. Researchers sometimes describe this as “adaptogenic” behavior, though that term is more marketing-friendly than scientifically precise. The practical takeaway is that men taking ashwagandha for testosterone support don’t appear to need to worry about a parallel estrogen spike.

The Anti-Estrogen Side of the Coin

Here’s where the story gets genuinely confusing. While whole ashwagandha root extract raises estradiol in menopausal women, one of its most studied individual compounds, withaferin A, behaves as an anti-estrogen at the cellular level. Lab studies have shown that withaferin A suppresses the expression of estrogen receptor-alpha (ER-α) in human breast cancer cells and reduces levels of ER-α regulated gene products. When researchers added estradiol to the cell cultures, it partially blocked withaferin A’s ability to trigger cancer cell death, confirming that the two are working in opposite directions at the receptor level.⁵

Computational modeling has also found that withaferin A binds to the estrogen receptor at the same key amino acid sites as tamoxifen, one of the best-known anti-estrogen drugs used in breast cancer treatment.⁶ This doesn’t mean ashwagandha is a substitute for tamoxifen. Computational binding studies are one of the earliest stages of drug research, and what happens in a computer simulation doesn’t automatically translate to what happens in a person’s body. But it does highlight that ashwagandha contains compounds pulling in opposite hormonal directions: the whole extract can raise circulating estradiol in the blood, while specific withanolides may block estrogen’s action at the receptor in certain tissues.

This apparent contradiction isn’t unique to ashwagandha. Tamoxifen itself blocks estrogen in breast tissue while mimicking estrogen in bone and the uterus. The body’s estrogen system is tissue-specific, and a single compound can have estrogenic effects in one place and anti-estrogenic effects in another. Ashwagandha, with its complex mix of bioactive compounds, seems to work through multiple pathways simultaneously, and isolating one compound’s effect doesn’t predict what the whole extract does systemically.

Implications for Hormone-Sensitive Conditions

This dual nature matters enormously for people with conditions that are sensitive to estrogen levels. For PCOS, ashwagandha’s potential to normalize gonadotropin levels and reduce cortisol has generated interest, though the clinical evidence in PCOS patients specifically is still in early stages. The review literature describes therapeutic potential based on ashwagandha’s ability to restore ovarian function in preclinical PCOS models and improve metabolic markers, but cautions that robust human trials in this population are still needed.³

For breast cancer, the picture is more nuanced. Lab and animal research has suggested that ashwagandha, and withaferin A in particular, may have potential against both estrogen-receptor-positive and triple-negative breast cancers.⁷ The anti-estrogen receptor activity of withaferin A is one mechanism being explored, along with several estrogen-independent pathways. But none of this has been tested in clinical trials in cancer patients. The simultaneous presence of compounds that could raise circulating estradiol and compounds that could block estrogen receptors makes it impossible to predict with confidence what ashwagandha would do in someone with estrogen-receptor-positive cancer. If you have a hormone-sensitive condition, this isn’t something to experiment with on your own.

When Multi-Herb Formulas Muddy the Picture

If you’ve seen products marketed as “menopause support” that include ashwagandha alongside several other herbs, be aware that the hormonal effects may not carry over from the single-herb trials. One randomized, placebo-controlled trial of an Ayurvedic botanical formulation containing ashwagandha (among other ingredients) found no significant changes in serum hormone levels between the active and placebo groups.⁸ The dose of ashwagandha in a multi-herb blend is usually lower than what was used in the single-ingredient trials, and other herbs in the formula could counteract or dilute its effects. If the estradiol-raising effect is what you’re after, the evidence applies specifically to standalone ashwagandha root extract at the doses used in the clinical trials, not to combination products.

Extract standardization also matters. Different commercial preparations pull different compounds from the plant in different proportions. Root-only extracts standardized to around 5% withanolides, like the widely studied KSM-66, have a different chemical profile than extracts using both root and leaf material or standardized to higher withanolide glycoside concentrations. The menopausal trials used specific root extracts at specific doses, and swapping in a different preparation doesn’t guarantee the same hormonal outcome. The supplement industry’s loose labeling standards make this a real practical concern.

Drug Interactions Worth Knowing About

Ashwagandha doesn’t just influence hormones directly. It can also affect how your liver processes other drugs, including hormonal medications. A study using primary human liver cells found that certain ashwagandha root extracts altered the expression and activity of CYP3A4, one of the most important liver enzymes for drug metabolism.⁹ CYP3A4 is involved in metabolizing a huge range of medications, including oral contraceptives, hormone replacement therapy, and many cancer drugs. If ashwagandha changes how fast your body clears these medications, it could alter their effectiveness or increase side effects.

This is especially relevant for anyone taking estrogen-containing medications. If CYP3A4 activity is altered, the effective dose of your birth control pill or HRT patch could shift up or down in ways neither you nor your doctor anticipated. The liver enzyme study was done in lab-grown cells, not in people, so the real-world magnitude of this interaction isn’t pinned down. But it’s one more reason to mention ashwagandha to your doctor if you’re on hormonal medications rather than treating it as “just a supplement.”

The Gut Microbiome Connection

A newer line of research is exploring whether ashwagandha’s effects on estrogen might partly run through the gut. The gut microbiome contains a collection of bacteria, sometimes called the estrobolome, that produce enzymes capable of converting estrogen metabolites back into their active forms. Changes in gut flora composition can therefore raise or lower the amount of active estrogen circulating in the body. A recent review on ashwagandha in breast cancer patients noted that its effects on gut microbiota suggest additional roles in estrogen metabolism and inflammatory regulation.¹⁰

This research is still in its earliest stages. Nobody has yet measured how much of ashwagandha’s estradiol-raising effect in menopausal women, if any, comes through changes in gut bacteria versus the stress-hormone pathway. But it opens the possibility that the estrogenic effects of ashwagandha aren’t limited to a single mechanism and could vary depending on an individual’s gut health. People who’ve taken antibiotics recently, for instance, or who have gut dysbiosis might respond differently than those with a stable microbiome.

Who Should Be Cautious

Given that ashwagandha can raise estradiol in at least some populations while simultaneously containing compounds that block estrogen receptors, a few groups should be particularly careful:

People with estrogen-receptor-positive cancers: The theoretical anti-estrogen activity of withaferin A has not been tested in human cancer patients, and the systemic estradiol increase seen in menopausal trials could be counterproductive. Do not self-prescribe ashwagandha if you have a history of hormone-sensitive cancer.
People on hormonal medications: The potential for ashwagandha to alter CYP3A4 activity means it could change how your body handles birth control pills, HRT, or anti-estrogen drugs like tamoxifen and aromatase inhibitors. Talk to your prescribing physician before adding it.
People with endometriosis or uterine fibroids: These conditions are fueled by estrogen. If ashwagandha raises circulating estradiol, it could theoretically worsen symptoms, though this hasn’t been directly studied.
Pregnant or breastfeeding women: Hormonal shifts during pregnancy are tightly regulated, and introducing an adaptogen with complex hormonal effects adds unpredictable variables. Most researchers and clinicians advise against use during pregnancy.

For otherwise healthy adults looking to manage stress or support general well-being, the hormonal shifts seen in trials have been modest enough that they haven’t raised safety alarms. The menopausal trials reported the estradiol increases alongside improvements in symptoms, not alongside estrogen-excess side effects. But “no red flags in short-term trials of otherwise healthy participants” is a lower bar than “proven safe for everyone.” The longest trials have run only a few months, so the effects of years of daily use remain unknown. Treat the current evidence as encouraging but incomplete, and adjust your expectations accordingly.