Most people think of hormones as individual numbers. Your testosterone is high or low. Your cortisol is elevated. Your estrogen is "fine."
But hormones don't work in isolation. They're produced in sequences, converted into other hormones by specific enzymes, metabolized through detoxification pathways, and cleared from the body. One hormone becomes the raw material for the next. The balance between them, and how efficiently your body processes them, matters as much as any single number.
This article walks through the major hormone pathways in men: how they connect, what each metabolite means, and why understanding the full picture gives you more useful information than a single lab result.
This is educational content. Bespoke Labs does not diagnose, treat, interpret results, or provide medical advice.
The Starting Point: How Stress Drives Hormone Production
Every hormone pathway in the body starts somewhere. For the adrenal hormones, including cortisol and DHEA, the starting point is the brain's response to stress.
Here's the sequence:
- Stress is perceived (physical, psychological, or metabolic).
- The hypothalamus (a region at the base of the brain) releases CRH (corticotropin-releasing hormone).
- CRH signals the pituitary gland (just below the hypothalamus) to release ACTH (adrenocorticotropic hormone).
- ACTH travels through the bloodstream to the adrenal glands (which sit on top of the kidneys) and tells them to produce hormones.
- The adrenal glands respond by producing cortisol (your primary stress hormone) and DHEA (a precursor to both androgens and estrogens).
This sequence is called the HPA axis (hypothalamic-pituitary-adrenal axis). It's the control system for your stress response, and it directly shapes your hormone profile.
When the HPA axis is activated repeatedly or chronically (from ongoing stress, poor sleep, overtraining, or illness), the balance between cortisol and DHEA can shift. Cortisol production may stay elevated while DHEA production declines. This matters because DHEA is a building block for testosterone and other androgens. If the adrenals are focused on cortisol output, there's less raw material available for androgen production.
DHEA: The Precursor Hormone
DHEA (dehydroepiandrosterone) is produced primarily in the adrenal glands. It's not a powerful hormone on its own, but it's the starting material for several important ones.
From DHEA, the body can go in several directions:
- DHEA-S (DHEA-sulfate): DHEA is converted to DHEA-S through a process called sulfation, which happens primarily in the adrenal glands. DHEA-S is the most abundant circulating form and acts as a reservoir. Inflammation can inhibit sulfation, which means less DHEA-S gets made and more DHEA gets pushed through other pathways instead.
- Androstenedione: DHEA can be converted to androstenedione, which is one step away from testosterone.
- Etiocholanolone and Androsterone: DHEA also metabolizes into these two compounds through different enzyme pathways. Etiocholanolone is produced via the 5b-reductase pathway (the less potent route). Androsterone is produced via the 5a-reductase pathway (the more potent route).
The Total DHEA Production (DHEA-S + Etiocholanolone + Androsterone) gives you a picture of your overall adrenal androgen output. If this total is low, the adrenals may not be producing enough raw material to support downstream hormone levels.
DHEA-S can be measured through standard blood work. It's one of the most useful markers for assessing adrenal androgen production.
The Androgen Pathway: From DHEA to Testosterone to DHT
Once DHEA has been converted to androstenedione, the next step is testosterone.
Androstenedione to Testosterone: This conversion is handled by an enzyme called 17b-HSD. Testosterone is the primary circulating androgen in men, and it's the one most people are familiar with. It influences muscle mass, energy, mood, libido, recovery, and body composition.
But testosterone itself isn't the end of the line. It can be converted further.
Testosterone to 5a-DHT (dihydrotestosterone): The enzyme 5a-reductase converts testosterone into 5a-DHT, which is roughly three times more potent than testosterone. DHT is the androgen most responsible for effects in specific tissues, including the prostate, skin, and hair follicles. This is why elevated DHT is associated with hair loss (androgenic alopecia) and prostate enlargement.
5a-DHT to 5a-Androstanediol: DHT is further metabolized into 5a-androstanediol, which is considered the best marker of how much DHT activity is happening at the tissue level. If 5a-androstanediol is elevated, it suggests significant DHT production in the tissues, even if circulating DHT levels appear normal on a standard blood test.
The 5a vs 5b balance: When androgens are metabolized, they can go through either the 5a-reductase pathway (producing more potent metabolites like androsterone and DHT) or the 5b-reductase pathway (producing less potent metabolites like etiocholanolone). The ratio between these two pathways tells you whether the body is favouring the more androgenic route or the less androgenic route.
A strong preference for the 5a pathway may contribute to androgen excess symptoms (hair loss, acne, prostate issues). A preference for the 5b pathway means the body is processing androgens through the less potent route.
How Testosterone Becomes Estrogen: The Aromatase Pathway
Men produce estrogen too. Not in the same quantities as women, but it's a normal and necessary part of male physiology. The problem isn't estrogen itself. It's when the balance between testosterone and estrogen shifts too far.
The conversion works like this:
- Testosterone is converted to Estradiol (E2) via the aromatase enzyme.
- Androstenedione is converted to Estrone (E1) via the aromatase enzyme.
Estradiol (E2) is the most potent estrogen. In men, elevated E2 relative to testosterone can contribute to symptoms like reduced libido, water retention, and gynecomastia (breast tissue development). For more on how these hormones relate to erectile function and libido, see our article on erectile dysfunction and low libido.
Estrone (E1) is less potent than E2 (about 10% as potent) but is typically more abundant. It can still contribute to estrogenic symptoms and may promote more inflammatory cytokine production than other estrogens.
Estriol (E3) is a weak estrogen with potential anti-inflammatory properties. It's typically less clinically relevant in men.
The single strongest influence on aromatase activity is body fat percentage. Fat tissue contains aromatase. More body fat means more conversion of testosterone to estradiol. This is one reason why men with higher body fat often have lower testosterone and higher estrogen, and why losing body fat can shift this balance.
Estradiol can be measured through standard blood work.
Estrogen Metabolism: Phase 1 and Phase 2
Once estrogen has been produced, the body needs to metabolize and clear it. This happens in two phases, and the efficiency of each phase has health implications.
Phase 1: Hydroxylation
In phase 1, estrogens (primarily E1) are broken down into hydroxylated metabolites by CYP enzymes. There are three main pathways:
- 2-OH-E1 (via CYP1A1): This is considered the protective pathway. 2-OH-E1 is a relatively inactive metabolite.
- 4-OH-E1 (via CYP1B1): This is the potentially harmful pathway. 4-OH-E1 is a reactive metabolite that, if not properly neutralized, can form quinones, which are compounds that can bind to and damage DNA.
- 16-OH-E1 (via CYP3A4): This metabolite retains estrogenic activity. Higher levels can contribute to ongoing estrogenic effects.
The balance between these three pathways matters. A higher proportion going through the 2-OH route is generally considered favourable. A shift toward the 4-OH route is associated with oxidative stress and potential DNA damage.
Phase 2: Methylation and Detoxification
In phase 2, the hydroxylated metabolites from phase 1 need to be neutralized and prepared for elimination. The key process here 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 can bind to DNA and cause damage.
Glutathione (the body's primary antioxidant) also plays a role in neutralizing these reactive metabolites. If glutathione levels are depleted, the body's ability to handle the 4-OH pathway safely is reduced.
Methylation activity is influenced by nutrient status, particularly B vitamins (B6, B12, folate) and magnesium. Poor methylation means slower estrogen detoxification.
Standard blood work can measure your estradiol and estrone levels. The downstream metabolites (2-OH, 4-OH, 16-OH) and methylation ratios require specialized urine testing, which provides a more detailed picture of how your body is processing estrogen.
Cortisol: The Daily Pattern and What It Means
Cortisol follows a predictable daily rhythm called the diurnal pattern:
- Lowest at bedtime (when you should be winding down)
- Rises in the early morning hours before you wake
- Peaks about 30 to 60 minutes after waking (the cortisol awakening response, which gives you the energy and alertness to start the day)
- Gradually declines through the afternoon and evening
When this pattern is disrupted, things you might notice include:
- Difficulty waking up or feeling alert in the morning (low morning cortisol)
- Wired at night, difficulty falling asleep (elevated evening cortisol)
- Afternoon energy crashes (steep mid-day decline)
- Flat pattern throughout the day (low overall output, sometimes called HPA axis dysfunction)
Cortisol vs Cortisone: Cortisol (active) and cortisone (inactive) are interconverted by the enzyme 11b-HSD. The body can shift the balance between them depending on need. In response to acute stress or infection, the body may shift toward more active cortisol. In response to chronic stress or long-term inflammation, the body may shift toward more inactive cortisone to protect tissues from sustained cortisol exposure.
Metabolized cortisol (the total of cortisol metabolites THF + THE) reflects your total cortisol production for the day. This can be different from your free cortisol level, because some people produce a lot of cortisol but also clear it quickly, so their circulating levels look normal even though their adrenals are working overtime.
Cortisol can be measured through standard blood work (a morning fasting draw is most common). For a full daily pattern, salivary or urine cortisol testing provides more detail.
The Anabolic-Catabolic Balance: DHEA vs Cortisol
Your body is constantly balancing two processes:
- Anabolic (building): driven by androgens like DHEA and testosterone. These hormones support tissue growth, repair, muscle protein synthesis, and recovery.
- Catabolic (breaking down): driven by cortisol. Cortisol promotes tissue breakdown, mobilizes energy stores, and suppresses immune function when elevated chronically.
When DHEA production is strong relative to cortisol, the body is in a more anabolic state, favouring repair and growth. When cortisol is significantly higher than DHEA, the body is in a more catabolic state, favouring breakdown.
Chronic stress, poor sleep, and overtraining all push this balance toward the catabolic side. This is one mechanism through which stress suppresses testosterone: the adrenals prioritize cortisol over DHEA, and DHEA is the raw material for testosterone production.
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 testosterone production (most testosterone is produced during deep sleep)
- 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 daily cortisol pattern
What You Can Test Through Standard Blood Work
Understanding the pathways is one thing. Testing them is another. Standard blood tests can measure many of the key hormones in these pathways:
Androgens:
- Total testosterone
- Free testosterone
- DHEA-S
- Estradiol (E2)
Pituitary signals:
- LH (luteinizing hormone) and FSH (follicle-stimulating hormone), which tell you whether the brain is properly signalling the testes
- Prolactin
Thyroid (which interacts with the entire hormone system):
- TSH, Free T4, Free T3
Adrenal:
- Cortisol (morning fasting)
- DHEA-S
Other relevant markers:
- SHBG (sex hormone-binding globulin), which affects how much testosterone is available for use
- Vitamin D, B12, B6, Magnesium, which are nutrient cofactors for these pathways
- hs-CRP (inflammation marker, relevant to aromatase activity and DHEA-S sulfation)
For a deeper look at downstream metabolites, phase 1 and phase 2 estrogen metabolism ratios, daily cortisol patterns, and the 5a/5b androgen ratios, specialized urine testing provides a more detailed picture.
Key Takeaways
- Hormones are produced in pathways, not in isolation. Testosterone doesn't just appear. It's built from DHEA, which is produced by the adrenals in response to signals from the brain.
- Stress directly competes with androgen production. The HPA axis drives both cortisol and DHEA, and chronic stress tilts the balance toward cortisol.
- Testosterone can convert to estrogen (via aromatase) and to DHT (via 5a-reductase). Both of these conversions matter. Body fat drives aromatase activity.
- Estrogen needs to be metabolized and cleared properly. The phase 1 hydroxylation pathway and phase 2 methylation pathway determine whether estrogen metabolites are safely detoxified or become reactive.
- Nutrient cofactors (B6, B12, magnesium, glutathione) are essential for these pathways to function.
- Standard blood tests can measure many of the key hormones. Specialized urine testing provides insight into the metabolites and ratios that blood tests don't cover.
Bespoke Labs provides access to lab testing and results delivery. We do not diagnose, treat, interpret results, or provide medical advice.