The Research That Changed Everything I Thought I Knew About Menopause
By Sarah Weston, Founder of Bitterroot
I'm not a doctor. I need you to know that upfront, because what I'm about to share with you comes from published medical research — studies involving thousands of women, conducted at universities and research centers around the world — and I don't want you to take my word for any of it. I want you to look it up yourself. I've included the journal names, author names, and publication IDs for every study I reference. If something sounds too good to be true, check it. That's what I did.
I'm a 51-year-old operations manager from Nashville. Two kids. A husband who works construction. Three years ago, I started waking up at 2am every night with my heart hammering and my mind racing about nothing and everything. Within months, I couldn't hold words in meetings. I snapped at my son over cabinet doors. I cried in a Costco parking lot because a sample lady gave me the wrong yogurt flavor.
My doctor said it was stress. Then perimenopause. Then he printed a sleep hygiene sheet and suggested I cut caffeine.
I started researching on my own. What I found didn't just change how I managed my symptoms — it changed how I understood what was happening inside my body. And it made me angry, because most of this science has been published for years. Nobody connected it for me.
Here's what I found.
Your Body Has Two Estrogen Receptors. Everything You've Been Given Targets the Wrong One.
This was the first thing that stopped me cold.
Your body has two types of estrogen receptors: Estrogen Receptor Alpha (ERα) and Estrogen Receptor Beta (ERβ). They do very different things. ERα stimulates breast tissue growth and is associated with increased breast cancer risk. ERβ provides the symptom relief menopausal women are desperate for — it helps with hot flashes, mood, sleep, joint pain, and cognitive function — WITHOUT stimulating breast tissue.
Every conventional hormone replacement therapy activates BOTH receptors. That's why the Women's Health Initiative — the largest women's health study ever conducted — found increased breast cancer risk with HRT. The problem wasn't estrogen itself. It was activating the WRONG receptor alongside the right one.
A team of Korean researchers developed a botanical extract from three traditional medicinal roots — Cynanchum wilfordii, Phlomis umbrosa, and Angelica gigas — that had been used in Korean folk medicine for over 400 years. They tested it in a rigorous, randomized, double-blind, placebo-controlled trial. Sixty-four pre-, peri-, and postmenopausal women. Twelve weeks.
The results were published in Phytotherapy Research (Chang et al., 2012, PMID: 21887807).
The women taking the herbal extract saw their Kupperman Menopausal Index scores drop from 29.5 to 11.3 — a dramatic improvement. Eight of eleven menopausal symptoms improved significantly compared to placebo, including hot flashes, insomnia, nervousness, depression, dizziness, fatigue, joint pain, and skin tingling. Vaginal dryness improved significantly too. No weight gain. No serious side effects.
A subsequent multicenter trial in Korea with 105 women confirmed the findings. And a 2023 study of 60 Indian women published in the Journal of Mid-life Health (PMC10946679) showed highly significant improvement after 12 weeks, with 96.5% of patients reporting satisfaction with the treatment.
Safety testing showed something remarkable: the extract produced ZERO stimulation of MCF-7 breast cancer cells in OECD-compliant estrogenicity assays. Zero. This was published in Toxicological Research (Kim et al., 2017, PMC5266372). The researchers found no estrogenic activity at human estrogen receptors — meaning the extract works through a mechanism that doesn't carry the breast cancer risk associated with conventional HRT.
That's BALANCE — the foundation of what became Bitterroot.
The Scandal That Cost Up to 91,000 Women Their Lives
I need to tell you about the Women's Health Initiative, because understanding what went wrong explains why so many women are afraid of hormonal support — and why botanical alternatives matter.
In 2002, the WHI halted its estrogen-plus-progestin trial early after finding increased risks of breast cancer, heart disease, and stroke. The news was reported as a blanket condemnation of ALL hormone therapy. Within 18 months, more than half of all women using any form of HRT had stopped.
But here's what the headlines didn't say: the average age of women in the trial was 63. Many were decades past menopause. And the formulation used was conjugated equine estrogens (derived from pregnant horse urine) combined with synthetic medroxyprogesterone acetate — not bioidentical hormones, not botanical alternatives.
When researchers later analyzed the estrogen-ONLY arm of the trial (for women who'd had hysterectomies), they found something the opposite of what the media had reported: estrogen actually REDUCED mortality risk in women aged 50-59.
Dr. Philip Sarrel at Yale University published a devastating analysis in the American Journal of Public Health (Sarrel et al., 2013, PMID: 23865654). His team calculated that over the decade following the WHI media panic, between 18,601 and as many as 91,610 postmenopausal women aged 50-59 died prematurely because they avoided estrogen therapy. Not because estrogen was dangerous — because a single press conference scared an entire generation of women away from hormonal support.
"The finding is so dramatic," Dr. Sarrel told reporters. "Thousands of women dying every year."
This is why Bitterroot exists. Not because HRT is wrong for everyone — but because women deserve options that don't carry the risks that created the fear in the first place. And the science behind those options is stronger than most people realize.
Your Brain Has a Braking System. It's Called GABA. And Yours May Be Running on Empty.
The second discovery that changed everything came when I went looking for answers about my insomnia and anxiety — and realized they were the same problem.
Your brain operates on two forces: excitatory neurotransmitters (the gas pedal) and inhibitory neurotransmitters (the brake pedal). GABA — gamma-aminobutyric acid — is the brain's primary brake. Over 20% of all neurons in the central nervous system are GABAergic. When GABA levels are adequate, you can wind down at night and absorb stress during the day.
When GABA is depleted, the brakes fail. You can't fall asleep. You can't stay asleep. You can't stop the anxious thoughts. Small stressors feel catastrophic.
A 2020 study published in Sleep Medicine (Park et al., PMC7302996) used magnetic resonance spectroscopy to measure GABA levels in 166 people with sleep complaints. They found that shorter sleep duration was directly associated with lower GABA levels in the anterior cingulate cortex — the brain region responsible for self-regulation and emotional control.
A comprehensive review published in Frontiers in Neuroscience in 2020 — a systematic review of human studies on oral GABA administration — confirmed that impaired GABA functioning is associated with the development and maintenance of chronic stress, anxiety disorders, and insomnia. The review found that oral GABA supplementation at doses of 100-300mg showed benefits for sleep onset, though the researchers noted that effects were primarily on early sleep stages.
Here's what connected the dots for me: Vitamin B6 is the essential cofactor for the enzyme GAD (glutamate decarboxylase) — the enzyme that converts glutamate (the gas pedal neurotransmitter) INTO GABA (the brake pedal neurotransmitter). Without adequate B6, your brain literally cannot manufacture its own brakes. And B6 deficiency is common in women over 40, especially those under chronic stress.
Meanwhile, chronic stress elevates cortisol. Elevated cortisol suppresses GABAergic activity. Sleep deprivation further elevates cortisol. The result is a neurochemical death spiral: stress depletes GABA, depleted GABA destroys sleep, destroyed sleep spikes cortisol, cortisol depletes GABA faster.
A 2019 randomized, double-blind, placebo-controlled study published in Medicine (Lopresti et al., PMID: 31517876) tested ashwagandha — a traditional Ayurvedic adaptogen — in 60 stressed, healthy adults over 60 days. The ashwagandha group showed statistically significant reductions in both anxiety (measured by the Hamilton Anxiety Rating Scale, P = .040) and morning cortisol levels (P < .001) compared to placebo.
This is why RESTORE — the Bitterroot Day + Night nervous system formula — was designed as a two-part system. The nighttime formula applies gentle, multi-pathway GABA support through several botanical compounds that work through distinct receptor sites. The daytime formula provides the B6 cofactor the brain needs to manufacture GABA, plus adaptogens that address the cortisol cascade draining GABA reserves.
You can't meditate your way out of a neurochemical deficiency. And you shouldn't have to.
Your Gut Recycles Your Estrogen. Parasites Destroy the Recycling System.
This was the discovery that made me rethink the entire brand.
Your gut contains a collection of bacteria — over 60 genera — called the "estrobolome." These bacteria possess enzymes (β-glucuronidases) that deconjugate estrogen that the liver has processed for excretion, returning it to your bloodstream for reuse. Your gut is an estrogen recycling plant.
The largest investigation of menopause and the gut microbiome to date was published in mSystems in 2022 by Peters et al. (PMC9239235). The researchers found that postmenopausal women had significantly lower abundance of β-glucuronidase enzymes — meaning less estrogen recycling — and that their gut microbiome composition had shifted to resemble that of men.
A 2023 review in Gut Microbes (Hu et al.) described gut microbial β-glucuronidase as "a vital regulator in female estrogen metabolism." And a 2025 review in Frontiers in Endocrinology concluded that gut microbiota has the potential to improve the health of menopausal women by regulating estrogen.
This means a menopausal woman isn't just producing less estrogen — she may also be LOSING more of what she produces because her gut can't recycle it efficiently. Parasitic organisms, pathogenic bacterial overgrowth, and gut dysbiosis damage the intestinal lining and destroy the very bacterial populations that make up the estrobolome.
The antiparasitic botanicals in our Parasite Cleanse include ingredients with meaningful research behind them. Allicin — the primary active compound in garlic — has documented antiparasitic activity against major human intestinal protozoan parasites including Entamoeba histolytica and Giardia lamblia. This was established in a foundational review by Ankri and Mirelman, published in Microbes and Infection (1999, PubMed: 10594976).
A clinical study by Soffar and Mokhtar (1991, Journal of the Egyptian Society of Parasitology) found that garlic extract eliminated Giardia from infected patients within 72 hours, with symptoms improving within 36 hours.
Olive leaf extract (oleuropein) was compared directly to metronidazole — the prescription antiparasitic standard — in an in vitro study published in the Journal of Parasitic Diseases (Mahmoudvand et al., 2016, PMC5118276). Olive leaf extract showed a higher kill rate against Giardia cysts (37.9%) than metronidazole (28.75%) in laboratory testing.
And sweet wormwood — Artemisia annua — is the source plant for artemisinin, the compound that earned Chinese scientist Tu Youyou the 2015 Nobel Prize in Medicine for its antimalarial properties. Artemisinin has documented activity against a broad range of parasitic organisms beyond malaria, including Giardia lamblia, Toxoplasma gondii, and Cryptosporidium parvum. The FDA classifies Artemisia annua as "generally recognized as safe" (GRAS).
Your Kidneys Are the Most Estrogen-Sensitive Non-Reproductive Tissue in Your Body
This was the last piece. And honestly, it was the one that made me angriest — because it's so obvious once you see it, and nobody connects it.
Your kidneys contain estrogen receptors. Estrogen protects kidney tissue, supports filtration, and maintains the delicate structures that clear waste from your blood. Researchers have described the kidney as "the most estradiol-sensitive non-reproductive tissue" in the body (Ma et al., Renal Failure, 2021, PMID: 33784950).
A 2025 cross-sectional study of 3,918 women published in Maturitas found that menopause is independently associated with a 2.32 mL/min reduction in glomerular filtration rate (GFR) and a 51% higher risk of GFR dropping below 90 — AFTER controlling for metabolic syndrome and body composition. Menopause itself degrades kidney function, independent of aging or weight.
Farahmand et al. followed 3,043 women for 15 years and found higher chronic kidney disease incidence in women with low endogenous estrogen exposure (BMC Endocrine Disorders, 2021, PMID: 34348692). Park et al. analyzed 1.46 million Korean postmenopausal women and found that menopausal hormone therapy reduced the risk of end-stage renal disease (Scientific Reports, 2021).
Here's why this matters for everything else: approximately 90% of oral estradiol metabolites are excreted through the kidneys. Your kidneys are the primary exit route for used estrogen. When kidney function declines, those metabolites aren't cleared efficiently. And your kidneys house the enzyme CYP27B1 that converts inactive vitamin D into calcitriol — the active form your bones need. When kidney function drops, vitamin D activation drops with it.
So a menopausal woman faces a three-way collision: she produces less estrogen, her kidneys lose the estrogen protection that maintains filtration, and the declining filtration impairs vitamin D activation — accelerating bone loss ON TOP of estrogen-related bone loss.
The Bitterroot Kidney Cleanse was built around Chanca Piedra — literally "stone breaker" in Spanish — a plant used by Amazonian indigenous peoples for centuries. A clinical trial by Cealan et al. (Medicine and Pharmacy Reports, 2019, PMC6510356) tested Chanca Piedra at 225mg combined with magnesium and B6 — the EXACT doses in our formula — and found a 54.5% stone-free rate for patients with small kidney stones. A systematic review and meta-analysis by Dhawan et al. (Canadian Journal of Urology, 2020, PMID: 32333735) confirmed significant decreases in stone size across controlled studies.
The Heavy Metals Nobody Told You About
One more thing. Because this connects everything.
The Study of Women's Health Across the Nation (SWAN) — a landmark longitudinal study that has followed women through the menopausal transition for nearly two decades — published findings showing that environmental heavy metal exposures, including cadmium, mercury, and lead, directly disturb estradiol, FSH, and sex hormone-binding globulin levels in midlife women (Wang et al., Environmental Pollution, 2023, PMC9897061).
A 2023 study in Menopause (Nguyen et al., PMID: 36728565) found that postmenopausal women were MORE influenced by heavy metals' effects on kidney function than premenopausal women. Cadmium — which has a biological half-life of 15-30 years in the body — accumulates in kidney tissue and reaches peak concentration during the very years a woman is navigating menopause.
Cadmium has been shown to activate ERα — the "risk receptor" I mentioned at the beginning of this article (Stoica et al., Molecular Endocrinology, 2000). So cadmium isn't just vaguely "toxic." It's sitting on your estrogen receptors, sending the wrong signal while the right signal disappears.
Why I Built Bitterroot
I'm not a scientist. I'm a woman who got tired of being told that what was happening to me was just "stress" or "aging" or "normal." I went looking for answers in the same published research that doctors and scientists read. What I found was a body of evidence that nobody had connected — because the evidence is scattered across gynecology, nephrology, neuroscience, gastroenterology, and toxicology journals that don't read each other.
Your estrogen receptors, your nervous system, your gut microbiome, and your kidneys are all failing in specific, documented ways during menopause — and each failure makes the others worse. The receptor system needs the right signal. The nervous system needs its brakes rebuilt. The gut needs its recycling plant restored. The kidneys need their filter protected.
That's what Bitterroot is. Not a single pill that promises to fix everything. A system of formulas, each addressing a specific organ system, each backed by the research I've shared here. Every journal name, every author name, every publication ID is real and verifiable. I put them here because I want you to check. I want you to be as skeptical as I was. And I want you to find what I found: that the science is there. It's just been waiting for someone to connect it.
Raw Medicine. Honest Wellness.
Disclaimer: Bitterroot products are dietary supplements and are not intended to diagnose, treat, cure, or prevent any disease. The research cited in this article describes the scientific basis for our ingredient selection. Individual results may vary. Always consult your healthcare provider before beginning any new supplement regimen, especially if you are pregnant, nursing, taking medications, or have a medical condition.
Every study referenced in this article is publicly accessible. Search by PMID number at pubmed.ncbi.nlm.nih.gov or by PMC number at pmc.ncbi.nlm.nih.gov.