When people talk about women's hormones, it's usually about estrogen and progesterone. Maybe testosterone. Rarely about how these hormones are actually connected, how one becomes the raw material for another, or how the body processes and clears them once they've done their job.
But hormones work as a system. They're produced in sequences, converted by enzymes, metabolized through detoxification pathways, and eliminated. The balance between them, and how efficiently your body handles each step, is often more informative than any single number on a lab report.
This article walks through the major hormone pathways in women: the stress response that drives adrenal hormone production, the androgen and estrogen pathways, progesterone and its metabolites, estrogen metabolism and detoxification, and cortisol's daily rhythm. Each section explains what the hormones and metabolites actually do and why they matter.
For a broader overview of blood tests relevant to women across different life stages, see our article on blood tests every woman should consider.
This is educational content. Bespoke Labs does not diagnose, treat, interpret results, or provide medical advice.
The Starting Point: How Stress Drives Hormone Production
The adrenal hormones, including cortisol and DHEA, are produced in response to a signalling cascade that starts in the brain.
Here's the sequence:
- Stress is perceived (physical, psychological, or metabolic).
- The hypothalamus releases CRH (corticotropin-releasing hormone).
- CRH signals the pituitary gland to release ACTH (adrenocorticotropic hormone).
- ACTH travels to the adrenal glands (which sit on top of the kidneys) and stimulates them to produce hormones.
- The adrenal glands respond by producing cortisol (your primary stress hormone) and DHEA (a precursor hormone that feeds into both androgens and estrogens).
This is the HPA axis (hypothalamic-pituitary-adrenal axis). It's the control centre for your stress response, and it has a direct impact on your entire hormone profile.
This matters more for women than many people realise. The adrenal glands produce approximately 75% of a woman's DHEA metabolites, which are the source of more than half of circulating testosterone and a significant portion of circulating estrogens. When the HPA axis is under chronic stress and prioritizes cortisol production, less DHEA is available as a building block for these downstream hormones.
DHEA: The Precursor That Feeds Both Androgens and Estrogens
DHEA (dehydroepiandrosterone) is produced primarily in the adrenal glands. It's not a powerful hormone by itself, but it's the raw material for many of the hormones that are.
From DHEA, the body can produce:
- DHEA-S (DHEA-sulfate): DHEA is converted to DHEA-S through sulfation in the adrenal glands. DHEA-S is the most abundant circulating form and serves as a reservoir. Inflammation can inhibit sulfation, meaning less DHEA-S is produced and more DHEA is diverted into other pathways.
- Androstenedione: an intermediate hormone, one step away from testosterone and also a precursor to estrone (E1).
- Etiocholanolone (via the 5b-reductase pathway) and Androsterone (via the 5a-reductase pathway): two different metabolic routes for DHEA. The balance between them tells you whether the body is favouring the more potent alpha pathway or the less potent beta pathway.
The Total DHEA Production (DHEA-S + Etiocholanolone + Androsterone) reflects your overall adrenal androgen output. In women, this is a major contributor to both androgen and estrogen levels.
DHEA-S can be measured through standard blood work and is one of the best markers for adrenal androgen production.
The Androgen Pathway in Women
Women produce androgens. This is normal and necessary. Androgens in women play a role in energy, libido, mood, muscle function, and bone density. Both low and elevated androgen levels can cause symptoms.
Sources of androgens in women:
- Adrenal glands: produce DHEA, DHEA-S, and androstenedione. These account for more than half of a woman's circulating testosterone.
- Ovaries: produce the remaining testosterone (roughly 25 to 50%) along with androstenedione.
The pathway:
Androstenedione is converted to Testosterone (via the enzyme 17b-HSD).
Testosterone can then be converted further:
Testosterone to 5a-DHT (dihydrotestosterone) via 5a-reductase. DHT is about three times more potent than testosterone. It's the androgen most associated with effects in the skin and hair follicles. Elevated DHT in women can contribute to symptoms like acne, hair thinning on the scalp, and unwanted facial or body hair (hirsutism).
5a-DHT to 5a-Androstanediol: the best marker of how much DHT activity is happening at the tissue level.
The 5a vs 5b balance: Just as in men, the balance between the 5a (more potent) and 5b (less potent) metabolic pathways matters. A preference for the 5a pathway, especially when paired with high androgens, may contribute to androgen excess symptoms. Conditions like PCOS (polycystic ovary syndrome) are associated with elevated androgens and increased 5a-reductase activity.
Testosterone, DHEA-S, and androstenedione can all be measured through standard blood work.
From Androgens to Estrogens: The Aromatase Pathway
Androgens are the raw material for estrogen production. The conversion happens through an enzyme called aromatase:
- Testosterone is converted to Estradiol (E2) via aromatase.
- Androstenedione is converted to Estrone (E1) via aromatase.
This is an important concept: estrogen doesn't appear from nowhere. It's built from androgens. The activity of aromatase determines how much androgen is converted to estrogen.
Aromatase activity is influenced by several factors, with body fat percentage being the most significant. Fat tissue contains aromatase. This is why postmenopausal women, whose ovaries have stopped producing estrogen, still have some circulating estrogen. It's being produced in fat tissue via aromatase conversion of adrenal androgens.
The Three Estrogens
Women produce three forms of estrogen, each with different potency and roles:
Estradiol (E2): The most potent estrogen and the one most directly related to symptoms. It's the primary estrogen during reproductive years, fluctuating significantly across the menstrual cycle. Elevated E2 can contribute to symptoms of estrogen excess. Low E2 is associated with symptoms of estrogen deficiency.
Estrone (E1): About 10% as potent as E2, but typically more abundant (about 5x higher in premenopausal women, about 10x higher in postmenopausal women). Because of its abundance, it's a significant contributor to overall estrogenic activity, especially after menopause. E1 may promote more inflammatory cytokine production compared to other estrogens.
Estriol (E3): A weak estrogen with potential anti-inflammatory properties. It's not typically a significant contributor to estrogenic symptoms in non-pregnant women. During pregnancy, E3 levels rise substantially as it's produced by the placenta.
Estradiol can be measured through standard blood work. When to test matters (see the section on cycle timing below).
Estrogen Metabolism: Phase 1 and Phase 2
Once estrogen has been produced and has done its job, the body needs to metabolize and clear it. This is a two-phase process, and the efficiency of each phase has real health implications.
Phase 1: Hydroxylation
In phase 1, estrogens (primarily E1) are broken down into hydroxylated metabolites by CYP enzymes. There are three main routes:
- 2-OH-E1 (via CYP1A1): the protective pathway. 2-OH-E1 is a relatively inactive metabolite. A higher proportion of estrogen going through this route is generally considered favourable.
- 4-OH-E1 (via CYP1B1): the potentially harmful pathway. 4-OH-E1 is a reactive metabolite. If it's not properly neutralized in phase 2, it can form quinones, which are reactive compounds that can bind to and damage DNA. This pathway is associated with oxidative stress.
- 16-OH-E1 (via CYP3A4): this metabolite retains estrogenic activity. Higher levels contribute to ongoing estrogenic effects in the body.
The balance between these three pathways matters. A shift toward the 4-OH route increases exposure to potentially genotoxic metabolites. A shift toward the 2-OH route is considered protective.
Phase 2: Methylation and Detoxification
In phase 2, the hydroxylated metabolites from phase 1 need to be neutralized and prepared for elimination. The primary process is methylation, carried out by an enzyme called COMT (catechol-O-methyltransferase):
- 2-OH-E1 is methylated into 2-Methoxy-E1 (safely detoxified).
- If 4-OH-E1 is not methylated, it can become a quinone (a reactive compound that binds to DNA and causes damage).
Glutathione, the body's primary antioxidant, also plays a critical role in neutralizing these reactive metabolites. If glutathione is depleted, the body's ability to safely process the 4-OH pathway is compromised.
Methylation activity depends on nutrient cofactors:
- Vitamin B6 is essential for methylation and estrogen detoxification
- Vitamin B12 and folate support the methylation cycle
- Magnesium is a cofactor for COMT
Gut health also matters. An enzyme called beta-glucuronidase, produced by certain gut bacteria, can reactivate estrogen that was already packaged for elimination and send it back into circulation. Gut dysbiosis (bacterial imbalance) can contribute to elevated circulating estrogen through this mechanism. This is sometimes called the "estrobolome," the collection of gut bacteria that influence estrogen metabolism.
Standard blood work can measure estradiol levels. The downstream metabolites (2-OH, 4-OH, 16-OH) and methylation ratios require specialized urine testing. The nutrient cofactors (B6, B12, magnesium) can be measured through standard blood work.
Progesterone: More Than Just the "Other" Hormone
Progesterone is often treated as the counterpart to estrogen, but it has its own pathway and metabolites that matter independently.
In premenopausal women, progesterone is primarily produced by the corpus luteum (the structure left behind in the ovary after ovulation). Levels rise after ovulation during the luteal phase and drop before menstruation.
Progesterone is metabolized into two main compounds:
- b-Pregnanediol (via 5b-reductase): the primary metabolite of progesterone. It's the best marker of total progesterone production.
- a-Pregnanediol (via 5a-reductase): an active metabolite that can bind to GABA receptors in the central nervous system. GABA is the brain's primary inhibitory neurotransmitter, the one responsible for calming activity, reducing anxiety, and promoting sleep.
The 5a-metabolism ratio for progesterone (a-Pregnanediol / b-Pregnanediol) tells you how much of your progesterone is being directed toward the pathway that affects GABA receptors. This is most relevant when progesterone levels are at luteal or higher levels, and especially relevant for women taking oral progesterone.
A higher proportion going to a-pregnanediol means more potential impact on mood and sleep through the GABA system. This can be positive (calming, sleep-promoting) or, in some cases, contribute to drowsiness or mood changes.
Progesterone can be measured through standard blood work, though timing matters (it should be measured in the mid-luteal phase, approximately 7 days after ovulation, to get a meaningful result).
Cycle Timing: Why When You Test Matters
Women's hormone levels change significantly throughout the menstrual cycle. Testing at the wrong time can produce results that look abnormal but are actually just reflecting the normal phase of the cycle.
Follicular phase (Days 1 to approximately 14):
- Estradiol starts low and rises as the follicle develops
- Progesterone is low
- LH and FSH are at baseline levels early in this phase
Ovulation (around Day 14):
- LH surges (this is the signal that triggers ovulation)
- Estradiol peaks just before the LH surge
- FSH also rises briefly
Luteal phase (approximately Days 15 to 28):
- Progesterone rises significantly (produced by the corpus luteum)
- Estradiol rises again to a secondary, smaller peak
- If pregnancy doesn't occur, both decline toward the end of the phase
General testing guidance:
- Days 2 to 5 (early follicular phase): the standard window for testing baseline estradiol, LH, FSH, and androgens. Hormones are at their most stable baseline during this window.
- Approximately 7 days after ovulation (mid-luteal phase): the window for testing progesterone, since this is when it peaks.
Cortisol: The Daily Pattern
Cortisol follows a predictable daily rhythm:
- Lowest at bedtime (supporting sleep onset)
- Rises in the early morning hours before waking
- Peaks about 30 to 60 minutes after waking (the cortisol awakening response, giving you energy and alertness)
- Gradually declines through the afternoon and evening
When this pattern is disrupted:
- Low morning cortisol can mean difficulty waking or feeling alert
- Elevated evening cortisol can mean difficulty falling asleep or feeling wired at night
- A flat pattern throughout the day may indicate HPA axis dysfunction from chronic stress
Cortisol vs Cortisone: Cortisol (active) and cortisone (inactive) are interconverted by the enzyme 11b-HSD. The body shifts the balance based on need. Acute stress or infection may shift toward more active cortisol. Chronic stress or prolonged inflammation may shift toward inactive cortisone to protect tissues.
Cortisol clearance rate describes how fast the body metabolizes and eliminates cortisol. Some people produce a lot of cortisol but clear it quickly, so their circulating levels may look normal even though their adrenals are working overtime. Obesity is associated with a faster cortisol clearance rate.
Cortisol can be measured through standard blood work (morning fasting). A full daily pattern requires salivary or urine cortisol testing.
The Anabolic-Catabolic Balance
Just as in men, women's bodies are constantly balancing two processes:
- Anabolic (building): supported by androgens like DHEA and testosterone. These hormones contribute to tissue growth, repair, bone density, and muscle maintenance.
- Catabolic (breaking down): driven by cortisol, which promotes tissue breakdown and energy mobilization.
When DHEA is strong relative to cortisol, the body favours repair and maintenance. When cortisol significantly outweighs DHEA, the body is in a more catabolic state.
This balance is particularly relevant for women under chronic stress, women who are overtraining, or women in perimenopause when adrenal hormone production becomes an increasingly important source of androgens and, through aromatase conversion, estrogens.
Melatonin and Its Role
Melatonin is produced by the pineal gland. It's your primary sleep hormone, signalling the body that it's time for sleep. Melatonin production is suppressed by light exposure (especially blue light) and increases in darkness.
Melatonin matters in the context of hormone pathways because:
- Sleep quality directly affects hormone production and the daily cortisol pattern
- Melatonin has antioxidant effects that may help protect against oxidative stress (relevant to estrogen metabolism and the 4-OH pathway)
- Disrupted circadian rhythm affects the balance of nearly every hormone in the system
What You Can Test Through Standard Blood Work
Standard blood tests can measure many of the key hormones in these pathways:
Estrogens and Progesterone:
- Estradiol (E2)
- Progesterone (timed to cycle phase)
Androgens:
- Total testosterone
- Free testosterone
- DHEA-S
- Androstenedione
Pituitary signals:
- LH and FSH (important for understanding cycle function, ovulation, and menopausal transition)
- Prolactin
Thyroid (interacts with the entire hormone system):
- TSH, Free T4, Free T3
Adrenal:
- Cortisol (morning fasting)
- DHEA-S
Nutrient cofactors:
- Vitamin D, B12, B6, Magnesium, Folate
- Ferritin and iron studies (iron deficiency is common in women and affects energy, recovery, and hormone function)
Other relevant markers:
- SHBG (sex hormone-binding globulin)
- hs-CRP (inflammation, relevant to aromatase activity and DHEA sulfation)
For a deeper look at estrogen metabolites and their ratios, progesterone metabolites (a-pregnanediol and its GABA receptor activity), daily cortisol patterns, and the 5a/5b androgen balance, specialized urine testing provides more detail.
Key Takeaways
- Hormones are produced in pathways, not in isolation. Estrogen is built from androgens. Androgens are built from DHEA. DHEA is produced by the adrenals in response to the brain's stress signals.
- The HPA axis (stress response) directly competes with hormone production. Chronic stress prioritizes cortisol over DHEA, reducing the raw material available for downstream hormones.
- Estrogen metabolism happens in two phases. Phase 1 hydroxylation determines which metabolites are produced (protective 2-OH vs potentially harmful 4-OH). Phase 2 methylation determines whether those metabolites are safely detoxified.
- Progesterone metabolites have their own effects, including activity on GABA receptors that can influence mood and sleep.
- Cycle timing determines what "normal" looks like. Testing hormones at the wrong point in the cycle produces misleading results.
- Nutrient cofactors (B6, B12, folate, magnesium, glutathione) are essential for these pathways. Gut health affects estrogen clearance.
- Standard blood tests can measure many of the key hormones. Specialized urine testing provides the metabolite-level detail.
Bespoke Labs provides access to lab testing and results delivery. We do not diagnose, treat, interpret results, or provide medical advice.