Menstruation and Menopause: Science, Myths, and Health Guidance

Dr. Jen Gunter, a San Francisco Bay Area OBGYN, author, and health communicator, emphasizes the critical need to bridge the communication gap in medicine. She aims to empower individuals with accurate information about their bodies, enabling them to make informed decisions, advocate for quality care, and discern factual health information from misinformation online. Her latest book, "Blood, The Science, Medicine, and Mythology of Menstruation," delves into these topics.

The Science of Menstruation

For millennia, menstruation has been viewed negatively across societies and religions, often labeled as toxic, dirty, or a sign of female inferiority. Ancient Greeks, for instance, believed women were fluidly imbalanced, and menstruation was an "overflow valve" for excess moisture, signifying physical inferiority. This historical weaponization of menstruation has contributed to a pervasive taboo, making it difficult to find historical records of how women managed their periods. This lack of information creates significant negative outcomes, as individuals may not recognize normal versus abnormal bodily functions, delaying necessary medical care or falling prey to unproven remedies.

Education about the menstrual cycle has historically been inadequate, often focusing solely on pregnancy prevention rather than comprehensive biological understanding. This narrow view leaves many with basic questions about their reproductive health. Dr. Gunter stresses that menstruation is fundamental to humanity, an essential part of human evolution that enabled the development of large brains. Understanding it is crucial for everyone, not just those who menstruate, to foster inclusivity in medicine and support loved ones.

Euphemisms and Terminology

Historically, euphemisms like "the rag" or "shark week" have been used to avoid the "shameful" topic of periods. The word "menstruation" itself derives from Latin and Greek roots meaning "monthly occurrence," unrelated to the word "men."

The common belief that a menstrual cycle is always 28 days is a myth. While it might be an average at certain ages, normal cycles can range from 21 to 38 days, with variations even within an individual's cycles (e.g., a 26-day cycle followed by a 32-day cycle).

The Uniqueness of Menstruation

Relatively few mammals menstruate, including humans, some great apes, bats, spiny mice, and elephant shrews. Menstruation is thought to have evolved independently four times. Other mammals have an estrous cycle, where the uterine lining is reabsorbed if pregnancy doesn't occur, unlike menstruation where the lining is shed.

Human menstruation involves a process called decidualization, a physical change in the uterine lining that occurs after ovulation due to progesterone release. This thick decidua acts as a "catcher's mitt" for an embryo and is crucial for the highly invasive human placenta, which requires significant oxygen for brain development. The decidua also plays a role in sensing embryo fitness. If pregnancy doesn't occur, this thick tissue cannot be reabsorbed and must be shed through menstruation, involving chemical changes that cleave the decidua from the uterus, opening blood vessels and expelling tissue and fluid.

The Menstrual Cycle Phases

The menstrual cycle begins on the first day of bleeding. Follicles in the ovary, on a 300-day journey, respond to follicle-stimulating hormone (FSH) and later luteinizing hormone (LH) from the brain. One follicle becomes dominant, producing estradiol (a potent estrogen) which stimulates uterine lining growth and breast tissue. A surge in LH triggers ovulation, releasing an egg. The remaining follicle tissue forms the corpus luteum, which produces progesterone. Progesterone converts the uterine lining into decidua, preparing it for implantation. If no pregnancy occurs, the corpus luteum's lifespan ends (10-14 days), progesterone levels drop, triggering menstruation.

The menstrual cycle is typically divided into two phases:

• Follicular Phase: Governed by FSH, leading to follicle development and estrogen production. Menstruation is part of this phase.
• Luteal Phase: Begins after ovulation, with the corpus luteum producing progesterone, preparing the uterus for potential pregnancy.

Menstrual Pain and Symptoms

Many people experience pain during ovulation, known as Mittelschmerz, believed to be caused by prostaglandins. Ovulation does not involve a "bursting" follicle but rather enzymatic dissolution. Ovaries do not alternate ovulation in a strict pattern; it can be haphazard. If one ovary is removed, the other compensates.

Common negative symptoms associated with the menstrual cycle include:

• Premenstrual Syndrome (PMS): A constellation of symptoms (breast tenderness, moodiness, hopelessness, food cravings) occurring only in the luteal phase.
• Menstrual Cramps (Dysmenorrhea): Painful cramps occurring before or during menstruation.
  • Primary Dysmenorrhea: Not related to another medical condition.
  • Secondary Dysmenorrhea: Related to conditions like endometriosis.
  • Cramps are caused by prostaglandins, which trigger uterine contractions to stop bleeding and can also cause pain and reduced blood flow.
• Menstrual Diarrhea: Occurs in about 12% of menstruating individuals, also due to prostaglandins.
• Premenstrual Dysphoric Disorder (PMDD): A more severe form of PMS with greater impact on daily life and depressive symptoms.

Menstrual pain is often minimized but can be as intense as labor pain. Untreated chronic pain can have long-term neurological ramifications. NSAIDs (nonsteroidal anti-inflammatory drugs) are a common and effective treatment as they block prostaglandins. If NSAIDs are ineffective, it may indicate an underlying condition like endometriosis.

Menstrual Cycle Tracking

Tracking menstrual cycles can be beneficial for identifying symptom patterns (e.g., PMS, menstrual migraines, pelvic pain) to aid medical diagnosis. However, "quantified self" tracking for optimization lacks scientific data. Many menstrual tracking apps use proprietary algorithms and can be inaccurate, leading users to blame their bodies rather than the app.

A significant concern with menstrual tracking apps is data privacy. In areas where abortion is illegal, this data can be subpoenaed and used to prosecute individuals. Users should be mindful of the data their phones collect, as it can be harvested and used against them, especially in a climate where women's reproductive rights are being challenged.

Hormonal Contraception and Menstruation

Hormonal birth control pills, taken daily, expose the body to progestin throughout the cycle. This prevents the uterine lining from thickening as it would naturally, resulting in lighter or absent periods. This is not harmful, as there is no thick lining to shed. The idea that menstruation is necessary to "release toxins" is a myth; the liver and kidneys handle detoxification.

Inclusivity in Menstruation

It's crucial to use inclusive language when discussing menstruation. While most menstruating individuals are cisgender women, trans men and non-binary people also menstruate. Not all women menstruate (e.g., those with hysterectomies, removed ovaries, or who are menopausal), and trans women do not. Using terms like "people who menstruate" ensures inclusivity.

The average age for menstruation to begin is around 12, but it can vary. If it hasn't started by age 16 or begins before age 8 or 9, medical consultation is advised. The age of onset does not predict the age of menopause.

The Science of Menopause

Menopause is the cessation of menstruation, a universal experience that is often poorly understood. It is not a disease but a natural biological transition, similar to puberty or pregnancy. The framing of menopause as a disease originated from pharmaceutical marketing in the 1960s.

Humans and orcas are among the few species that live long after reproduction ceases. The "grandmother hypothesis" suggests that menopause is evolutionarily beneficial, allowing older women to contribute to the survival and success of their grandchildren by providing care, knowledge, and resources, thereby ensuring the continuation of their "grand genetics."

Menopause Transition and Stages

Menopause is officially diagnosed after 12 consecutive months without a period, typically occurring between ages 45 and 55. The period leading up to menopause, characterized by hormonal changes, is called the menopause transition (also known as perimenopause or premenopause), lasting 4 to 7 years or longer. During this time, hormone levels fluctuate chaotically, leading to irregular periods, which eventually space out and then cease.

• Premature Menopause: Occurs between ages 40 and 44.
• Primary Ovarian Insufficiency: Occurs before age 40 and requires investigation.
• Surgical Menopause: Occurs when ovaries are removed, inducing immediate menopause.

Hormone testing is generally not needed for menopause diagnosis in the expected age range (45-55) but is recommended for those under 45 to rule out other medical conditions. Hormone levels fluctuate too much during the menopause transition to be reliable indicators.

Menopause Symptoms

Menopause is associated with a wide range of symptoms, many of which are understudied. Common symptoms include:

• Vasomotor Symptoms: Hot flashes and night sweats.
• Vaginal Symptoms: Dryness, irritation, and pain with sex.
• Cognitive Symptoms: Brain fog.
• Other Physical Symptoms: Palpitations, joint pain.

The duration and severity of symptoms vary greatly among individuals, similar to the diverse experiences of pregnancy.

Managing Menopause

A strong health foundation, particularly exercise, is crucial for managing menopause. Exercise positively impacts risks for type 2 diabetes, heart disease, dementia, depression, and osteoporosis. Both aerobic and strength training are important.

Menopausal Hormone Therapy (MHT): MHT (formerly Hormone Replacement Therapy) is the gold standard for treating hot flashes and night sweats. It is a therapy, not a replacement for something "missing." Other treatments for hot flashes include new drugs and some epilepsy/depression medications. Vaginal estrogen is used for vaginal dryness.

MHT is not universally recommended as preventative care. Evidence-based "green light" indications include:

• Hot flashes and night sweats.
• Prevention of osteoporosis in high-risk individuals.

"Yellow light" indications, requiring individual discussion, include:

• Depression during the menopause transition (estrogen may help, but not after menopause).
• Joint pain (studies are not strong, but it may help some).
• Reduced risk of type 2 diabetes (not a global recommendation).

MHT is not recommended for preventing dementia, Alzheimer's, cardiovascular disease (though early use may have some benefits), brain fog (unless sleep deprivation from hot flashes is a factor), or weight gain. The decision to use MHT should be based on individual symptoms, risk profile, and safety.

Menstrual Irregularities in Menopause Transition: Heavier periods and conditions like fibroids or adenomyosis can occur. Hormonal birth control pills (estrogen-containing) or hormonal IUDs can manage heavy bleeding.

Pharmaceutical vs. Compounded Hormones: Dr. Gunter strongly advocates for pharmaceutical hormone preparations (pills, patches, gels) because they are rigorously tested for absorption, dosage, and safety. Compounded products lack this research and oversight, leading to unreliable absorption, unknown dosages, and potential contamination. "Bioidentical" is a marketing term; most pharmaceutical estrogens are plant-based and chemically identical to natural hormones. Testosterone is not a standard part of MHT and is only evidence-based for specific libido issues after other therapies have been explored.

Sorting Science from Snake Oil

With abundant online health content, it's essential to critically evaluate information:

1. Too Good to Be True: Be skeptical of bold promises or "secret" cures. Legitimate medical breakthroughs are widely reported.
2. Supplement Sales: Be wary of individuals who sell or promote supplements. Their medical information may be biased due to financial incentives. Supplements are largely unregulated and untested.
3. Fact-Checking: Immediately fact-check online information. Use search engines with reputable medical organizations (e.g., ACOG, SOGC, Menopause Society, CDC, WHO) to filter results.
4. Seeking Medical Care:
   • Write down all symptoms to discuss with your doctor.
   • Advocate for yourself, using information from professional medical societies if you feel unheard.
   • Choose board-certified physicians over less regulated practitioners like naturopaths or chiropractors.
   • Investigate doctors' financial ties to pharmaceutical companies (publicly available data).
   • Be cautious of health advice from celebrities, as it may not be evidence-based.

Supplements: What You Need to Know

Supplements are intended to address dietary shortfalls. Few have strong evidence-based support.

Evidence-Based Supplements:

• Prenatal Vitamins: Essential for healthy pregnancy due to common dietary shortfalls in folate and other micronutrients.
• Multivitamins: Recommended after bariatric surgery due to nutrient malabsorption.
• Iron Supplements: For iron deficiency anemia, as dietary iron alone is often insufficient.
• Potassium Supplements: For individuals on diuretics that cause potassium loss.

Supplements with Reported Medical Benefits (Varying Evidence):

• Magnesium: May help with constipation (some evidence).
• Black Cohosh: For hot flashes (no good scientific support).
• Biotin: For hair growth (no data to support).

Unstudied and Potentially Dangerous Supplements:

• Products combining multiple vitamins, minerals, and botanicals for "organ support," "metabolism boosting," or "fat burning" are rarely studied and often adulterated.
• Supplements for libido, sport enhancement, and metabolism have a higher risk of contamination.
• Contamination with heavy metals (e.g., lead), toxic molds, or fungi is a significant concern, especially with Ayurvedic products (about 20% risk of lead contamination).

How to Choose Supplements:

1. Necessity: Is there good evidence to support taking it for your specific need? Consult reputable sources like the CDC, ACOG, or the US Office of Dietary Supplements.
2. Source of Recommendation: Is the recommendation from a medical professional society or someone selling a product?
3. Third-Party Verification: Look for third-party certifications (e.g., USP verified label) to ensure purity and accurate labeling, as government regulation is limited in the US.
4. Avoid: Do not take supplements for sport enhancement or metabolism boosting, and be very wary of Ayurvedic products due to high contamination risks.

Dr. Gunter concludes by emphasizing that open conversation about menstruation and menopause is vital. Silence perpetuates shame and allows political powers to diminish the health and autonomy of half the population. Understanding these biological processes is crucial for advocating for oneself, accessing quality care, and driving necessary research.