Low Testosterone in Men: Symptoms, Testing, and Optimization (Beyond TRT)

You're tired all the time. Your libido is gone. Building muscle feels impossible. Brain fog is constant. You're more irritable than you used to be. Belly fat keeps accumulating no matter what you do.

Your doctor checks your testosterone. It comes back at 350 ng/dL. They say it's "within normal range" and send you home.

Here's the truth: "normal" doesn't mean optimal—and 350 ng/dL is functionally low, even if it's technically in range.

What Is Testosterone and Why Does It Matter?

Testosterone is the primary male sex hormone. It's produced mainly in the testes (95%) and partly by the adrenal glands (5%). Testosterone is responsible for:

• Libido and sexual function
• Muscle mass and strength
• Bone density
• Fat distribution (prevents belly fat accumulation)
• Red blood cell production
• Mood, motivation, and mental clarity
• Energy and vitality

Testosterone naturally declines with age—about 1–2% per year after age 30. But many men experience drops far steeper and earlier than expected due to lifestyle, stress, and metabolic dysfunction.

Symptoms of Low Testosterone

Low testosterone doesn't show up as one clear symptom—it's a constellation of issues:

Physical Symptoms:

• Low libido or erectile dysfunction
• Difficulty building or maintaining muscle
• Increased body fat (especially belly fat)
• Fatigue and low energy
• Reduced strength and endurance
• Loss of body hair
• Gynecomastia (breast tissue development)
• Hot flashes or night sweats

Mental/Emotional Symptoms:

• Brain fog and poor concentration
• Low motivation and drive
• Depression or mood swings
• Irritability
• Lack of confidence

Metabolic Symptoms:

• Insulin resistance
• Elevated blood sugar
• High cholesterol
• Increased visceral fat

If you recognize multiple symptoms from this list, testing is critical.

How to Test Testosterone Properly

Most doctors order a single total testosterone test. If you're above the bottom of the range, they say you're fine. This approach misses the nuance.

What to Test:

1. Total Testosterone

Measures all testosterone in your blood (bound + unbound).

2. Free Testosterone

Only 2–3% of testosterone is "free" (unbound and biologically active). This is the testosterone your body can actually use.

3. SHBG (Sex Hormone-Binding Globulin)

SHBG binds testosterone and makes it unavailable. High SHBG = low free testosterone even if total testosterone looks normal.

4. Estradiol (E2)

Men need some estrogen—but too much causes problems:

• Gynecomastia (man boobs)
• Water retention
• Mood swings
• Fat gain

Optimal estradiol in men: 20–30 pg/mL

5. LH and FSH

These pituitary hormones signal the testes to produce testosterone.

• Low LH/FSH + low testosterone = secondary hypogonadism (brain/pituitary issue)
• High LH/FSH + low testosterone = primary hypogonadism (testicular issue)

6. Additional Tests:

• Prolactin - Elevated prolactin suppresses testosterone and libido
• Thyroid Panel - Low thyroid mimics low T symptoms
• Fasting Insulin & Glucose - Insulin resistance lowers testosterone

What Causes Low Testosterone?

1. Obesity and Insulin Resistance

Fat tissue contains aromatase, an enzyme that converts testosterone to estrogen. The more body fat you have, the more testosterone you lose. Insulin resistance also directly suppresses testosterone production.

2. Chronic Stress

High cortisol suppresses the HPG axis (hypothalamus-pituitary-gonadal axis), which controls testosterone production. Chronic stress = chronic low testosterone.

3. Poor Sleep

Testosterone is produced during deep sleep. Sleep deprivation can lower testosterone by 10–15% after just one week.

4. Environmental Toxins

Endocrine disruptors mimic or block hormones:

• BPA (plastics)
• Phthalates (personal care products, plastics)
• Pesticides and herbicides
• Heavy metals

5. Nutrient Deficiencies

• Zinc - Critical for testosterone production
• Vitamin D - Acts as a steroid hormone; deficiency lowers testosterone
• Magnesium - Increases free testosterone

6. Other Causes:

• Chronic alcohol consumption
• Certain medications (opioids, statins, SSRIs)
• Testicular injury or dysfunction
• Natural aging (1-2% decline per year after 30)

How to Optimize Testosterone Naturally

Before considering TRT, try these evidence-based strategies:

2. Resistance Training

Heavy compound lifts (squats, deadlifts, presses) boost testosterone acutely and chronically.

• Lift 3–5× per week
• Focus on progressive overload
• Don't overtrain (excessive volume lowers testosterone)

3. Sleep 7–9 Hours

Prioritize deep sleep. Testosterone is produced during REM and deep sleep stages.

4. Reduce Stress and Cortisol

• Daily stress practices (breathwork, meditation, nature time)
• Adaptogenic herbs (ashwagandha, rhodiola)
• Reduce overtraining

5. Eat for Testosterone Production

• Healthy fats - Testosterone is made from cholesterol. Eat eggs, grass-fed meat, avocado, olive oil
• Protein - 1g per pound of body weight to support muscle and hormones
• Avoid processed foods, seed oils, excess sugar

6. Strategic Supplementation

• Zinc - 30–50 mg daily (if deficient)
• Magnesium - 400–600 mg daily
• Vitamin D - Optimize to 50–80 ng/mL
• Boron - 6–10 mg daily (increases free testosterone)
• Ashwagandha - 600 mg daily (lowers cortisol, raises testosterone)
• Tongkat Ali - 200–400 mg daily (supports LH and testosterone)

7. Reduce Estrogenic Exposure

• Avoid plastics (use glass or stainless steel)
• Choose organic produce (reduce pesticide exposure)
• Use non-toxic personal care products
• Filter your water

When to Consider Testosterone Replacement Therapy (TRT)

If lifestyle interventions don't work—or if your testosterone is clinically low (<300 ng/dL)—TRT may be appropriate.

Benefits of TRT:

• Increased energy and vitality
• Improved libido and sexual function
• Increased muscle mass and strength
• Fat loss (especially visceral fat)
• Better mood and mental clarity
• Improved insulin sensitivity

Types of TRT:

• Injections (testosterone cypionate or enanthate) - Most common, cost-effective
• Topical gels or creams - Convenient but variable absorption
• Pellets - Inserted under the skin, last 3–6 months
• Patches - Daily application

TRT Risks:

• Testicular atrophy (testes shrink)
• Infertility (suppresses sperm production)
• Elevated estrogen (if not managed)
• Increased red blood cell count
• Acne or oily skin

The Functional Approach: Find the Root Cause

Low testosterone is often a symptom of deeper dysfunction:

• Insulin resistance
• Chronic stress and HPA axis dysfunction
• Sleep disorders
• Nutrient deficiencies
• Environmental toxin overload

Addressing the root cause can restore testosterone naturally—without TRT.