Female Hormone Primer.

Days 1-5 (menses): estrogen and progesterone at lowest. Energy often low. Iron loss happens here — keep ferritin in check.

Days 6-13 (follicular): estrogen rises. Energy, mood, strength all favor this window. Best week for hard training.

Day 14 (ovulation): estrogen peaks, LH surges. Brief libido spike. Basal body temp jumps ~0.5°F (visible on Oura ring temperature data).

Days 15-28 (luteal): progesterone dominant. Body temperature elevated. Some women experience PMS or PMDD in late luteal phase.

What irregularity means: cycles longer than 35 days or shorter than 21, missed periods, very heavy bleeding, severe pain — all warrant workup. Common causes: PCOS, thyroid, perimenopause, hypothalamic amenorrhea (from low body fat, overtraining, or undereating).

Hormonal pattern: progesterone declines first (luteal-phase insufficiency), then estrogen becomes variable (often higher than normal, then low). The variability itself causes symptoms.

Symptoms: cycle length changes, sleep disturbances (often the first symptom, especially mid-cycle), hot flashes, mood changes, weight gain (often abdominal), brain fog, libido changes.

Workup: FSH (elevated suggests perimenopausal/menopausal), estradiol, progesterone (best mid-luteal phase), testosterone, DHEA-S, thyroid panel, vitamin D, B12, ferritin. AMH if fertility is still a question.

The trap: 'normal' labs are common in early perimenopause because labs sample one day in a highly variable system. Symptoms are valid evidence even when one-day labs aren't dramatic.

Estradiol — transdermal patch, gel, or pellet. Transdermal lower clot risk than oral. Dose to symptoms: hot flashes resolved, sleep improved, vaginal symptoms gone.

Progesterone — oral micronized progesterone (Prometrium) at night, 100-200mg. Sedating (sleep benefit). Required if you have a uterus and are taking estrogen (uterine cancer protection).

Testosterone — increasingly recognized in women. Cream or pellet at female doses (1/10 male dose). Improves libido, energy, mental clarity, lean mass.

DHEA — adrenal precursor. Some women find it helpful, others don't. Modest evidence.

The Women's Health Initiative (2002) scared a generation off HRT. The original interpretation was wrong; modern transdermal bioidentical HRT in women under 60 has much better risk-benefit. The cancer / cardiovascular fears applied largely to oral conjugated equine estrogens started 10+ years after menopause.

Muscle preservation is more critical for women. Lower starting lean mass; loss is harder to rebuild. Resistance training 3x/week is non-negotiable on GLP-1s.

Estrogen-GLP-1 interactions exist. Some women on HRT report mood and appetite shifts when starting GLP-1; protocols are still evolving.

Fertility: GLP-1s are contraindicated in pregnancy. Discontinue 2+ months before trying to conceive. Improves PCOS-related infertility in some users via metabolic effects on ovulation.

Bone density: rapid weight loss in postmenopausal women accelerates bone loss. DEXA bookends and resistance training are protective.