1. My Clinical Approach to Low Testosterone
Many men come to my clinic in Rhodes having already had a testosterone test — often on their own initiative — and are worried because the value looks low. The first thing I explain is that a single value is not enough for a diagnosis.
My role is to combine the symptoms, the clinical picture, a properly drawn laboratory measurement, and — where needed — further investigation of the cause, before we discuss any intervention, whether lifestyle-based or medical.
In practice, I always follow these steps:
- Confirmation with a second morning measurement before any diagnosis.
- Assessing symptoms together with the laboratory finding, not in isolation.
- Investigating reversible causes (weight, sleep, lifestyle) before considering TRT.
- Special attention to fertility when the patient wishes to have children.
The goal of this guide is to help you understand what genuinely affects testosterone — without exaggeration, and without replacing a proper andrological evaluation.
2. What Is Testosterone
Testosterone is the main male androgen hormone. It is produced mainly in the testes, and its production is regulated by the hypothalamic–pituitary–testicular axis.
Testosterone influences:
Libido
Muscle mass
Bone health
Red blood cell production
Body fat distribution
Mood / well-being
Sexual function
Sperm production, through the overall function of the axis
The relationship between testosterone and erections is not simple. Testosterone affects libido and plays a role in sexual function, but erections also depend on vascular, neurological, and psychological factors — see the section below.
3. Symptoms of Low Testosterone
Sexual Symptoms
- Reduced libido
- Fewer spontaneous / morning erections
- Erectile dysfunction in some men
- Reduced sexual activity
Physical Symptoms
- Reduced muscle mass
- Reduced strength
- Increased body fat
- Reduced bone density in severe chronic deficiency
- Possible gynecomastia in selected cases
- Reduced body hair in significant hypogonadism
General / Psychological Symptoms
- Fatigue
- Reduced energy
- Difficulty concentrating
- Reduced motivation
- Mood changes
These symptoms are non-specific and can result from many other conditions (e.g., depression, hypothyroidism, chronic illness). Laboratory confirmation is always needed before attributing them to low testosterone.
4. How Testosterone Is Tested
Initial testing usually relies on total serum testosterone. The blood draw should generally be done in the morning, ideally under consistent conditions, following the instructions of the laboratory or the treating physician.
If the first value is low or borderline, a repeat morning measurement on a different day is usually needed before any diagnosis is made.
Total & Free Testosterone, SHBG
SHBG (sex hormone-binding globulin) affects the relationship between total and bioavailable testosterone. When total testosterone is borderline, when abnormal SHBG is suspected, or when symptoms do not match the total value, evaluation of SHBG, albumin, and calculation of free testosterone (or another appropriate method) may be needed. No single “free testosterone” method should automatically be assumed equivalent to another without verification.
Other Hormone Tests to Investigate the Cause
Depending on the clinical picture, additional tests may be needed, such as:
LH (luteinizing hormone)
FSH (follicle-stimulating hormone)
Prolactin
SHBG
TSH / thyroid function, where relevant
Hematocrit / complete blood count
Glucose / HbA1c & metabolic work-up, where relevant
PSA before testosterone therapy, at appropriate ages/cases
LH/FSH helps distinguish between primary hypogonadism (a problem in the testes themselves) and secondary / hypogonadotropic hypogonadism (a problem in the hypothalamic-pituitary axis).
For a detailed description of the test, see our dedicated guide on the Testosterone Test.
5. Normal Testosterone Values
Reference ranges vary between laboratories and assay methods. Diagnostic cut-offs must always be interpreted together with symptoms — a single value, even below the laboratory’s reference range, is not enough on its own.
Different guidelines may use slightly different cut-offs. For instance, the American Urological Association (AUA) guideline references an indicative threshold around 300 ng/dL for defining low testosterone, while the Endocrine Society uses similar but not always identical thresholds. None of these cut-offs is an isolated diagnostic rule — they are always weighed together with symptoms and a repeat measurement.
6. How to Increase Testosterone Naturally
6.1 Losing Excess Body Weight
In men with excess body weight or obesity, weight loss can lead to a meaningful improvement in testosterone. This is one of the lifestyle interventions with the best supporting evidence, when obesity is present.
6.2 Exercise
Resistance training, regular aerobic activity, and overall physical activity are associated with better hormonal and metabolic health. There is a difference between the acute, temporary rise in testosterone right after exercise and long-term hormonal improvement — no single exercise permanently “boosts” testosterone.
6.3 Sleep
Chronic sleep deprivation can negatively affect the hormonal axis. Adequate sleep duration and quality matter, and possible sleep apnea should be evaluated when related symptoms are present (e.g., snoring, daytime sleepiness).
6.4 Diet
What matters is adequate energy intake, sufficient protein, balanced fats, and avoiding extreme crash diets or chronic excessive caloric restriction — not a special “testosterone diet”.
6.5 Alcohol
Excessive alcohol consumption can negatively affect testosterone and testicular function.
6.6 Chronic Stress
The relationship between chronic stress and testosterone is not straightforward, and the simplistic idea that “lowering cortisol raises testosterone” does not hold up. Overall health, sleep, psychological burden, and behaviors linked to chronic stress (e.g., poor diet, alcohol use, reduced exercise) can indirectly affect the hormonal axis.
7. Foods, Supplements & “Testosterone Boosters”
Are There Foods That Increase Testosterone?
No single food produces a clinically meaningful increase in testosterone in an otherwise healthy man. What matters more is an adequate diet, healthy body weight, sufficient nutrient intake, dietary variety, and avoiding significant nutritional deficiencies.
Zinc, Vitamin D, Magnesium
Correcting a genuine deficiency in zinc, vitamin D, or magnesium can be beneficial. This does not mean that high doses of these supplements raise testosterone in men without a deficiency — evidence for many “testosterone boosters” is limited or of low quality.
Do “Testosterone Boosters” Work?
- Many products are marketed with claims not supported by adequate clinical studies.
- Some supplements may have variable content of active ingredients.
- They should not replace the diagnosis of a possible hormonal disorder.
- "Natural" does not necessarily mean effective or safe.
8. Testosterone & Obesity
There is a two-way relationship: obesity is associated with lower testosterone. Increased body fat, metabolic disturbances, insulin resistance, and sleep apnea can all be linked to lower testosterone values.
Weight loss can improve both testosterone and overall metabolic health — which is why it is often the first and best-supported intervention in men with obesity and low testosterone.
9. Testosterone, Age & Erectile Dysfunction
Testosterone & Age
Testosterone can gradually decline with age. However, age alone is not a diagnosis of hypogonadism — an older man does not automatically need testosterone therapy. There must be both compatible symptoms and confirmed low values. “Age-related low T” is not necessarily pathological.
Testosterone & Erectile Dysfunction
Low testosterone can affect libido and sexual function. However, erectile dysfunction very often has vascular, metabolic, medication-related, neurological, or psychogenic causes. Testosterone should not be considered the sole cause of every erection problem.
10. Testosterone & Fertility
Exogenous testosterone can suppress LH/FSH and sperm production, leading to significant oligospermia or even azoospermia.
A man who wishes to have children should not arbitrarily start testosterone replacement therapy (TRT). Managing low testosterone in a man who intends to father children requires a specific andrological approach, which may include alternative treatment options rather than direct exogenous testosterone.
11. When Testosterone Replacement Therapy (TRT) Is Needed
TRT is considered when a combination of factors is present: compatible symptoms, repeatedly low testosterone, appropriate investigation of the cause, assessment of contraindications/risks, and a benefit–risk discussion with the treating physician.
Before starting TRT, and in line with current guidelines, physicians typically check: confirmation of low testosterone, hematocrit/complete blood count, PSA/prostate assessment where indicated, fertility intentions, cardiovascular risk, possible sleep apnea, and the causes of any potential secondary hypogonadism. This is not an exhaustive checklist that replaces clinical judgment.
For a detailed description of diagnosis, treatment, and monitoring, see our dedicated guide on Male Hypogonadism.
Natural Increase vs TRT
| Approach | When It Makes Sense | What It Can Achieve |
|---|---|---|
| Weight loss | Excess body weight / obesity | Can improve endogenous testosterone |
| Exercise | Sedentary lifestyle / low fitness | Improves overall health, can support normal levels |
| Better sleep | Sleep deprivation | Supports normal hormonal function |
| Correcting deficiencies | Documented deficiency (e.g., vitamin D) | Beneficial only if a genuine deficiency exists |
| TRT | Confirmed hypogonadism | Medical treatment — not a "natural booster" |
These options are not equivalent. TRT has specific medical indications — it is neither a “natural booster” nor an anti-aging treatment.
12. What Can Lower Testosterone
Obesity
Chronic illnesses
Severe acute illness
Sleep deprivation
Sleep apnea
Certain medications (e.g., opioids, glucocorticoids)
Excessive alcohol consumption
Testicular disorders
Pituitary / hypothalamic disorders
Prior chemotherapy or radiation
Genetic causes, in selected cases
Not every patient needs the same laboratory work-up — the investigation is tailored to the individual history and clinical picture.
Can Stress Lower Testosterone?
The relationship is complex. A low laboratory value should not simply be attributed to stress without further investigation. Chronic stress is often accompanied by poor sleep, weight changes, increased alcohol use, or reduced physical activity, all of which can affect overall health.
How Long Does It Take to Increase Naturally?
There is no fixed timeframe — it depends on the cause. Meaningful weight loss or correcting a genuine deficiency can produce a measurable effect over time (usually months, not days). A “boost” within a few days is not a realistic goal.
13. When to See an Andrologist
Persistent low libido
Repeatedly low testosterone
Erectile dysfunction along with other hypogonadism symptoms
Infertility
Reduced testicular volume
Gynecomastia
Severe fatigue with hormonal findings
Suspected pituitary disorder
Very low testosterone
Wanting to consider TRT
Wish to father children with concurrent low testosterone
14. Step-by-Step Diagnostic Pathway
Wish to have children → specific andrological evaluation before any exogenous testosterone.
15. Frequently Asked Questions
How can I naturally increase testosterone?
The best-supported approaches are losing weight if you carry excess body weight or obesity, regular exercise (especially resistance training), adequate quality sleep, and a balanced diet without extreme dieting. There is no "magic" method that guarantees a measurable result within a fixed timeframe.
What are the symptoms of low testosterone?
They include reduced libido, fewer morning erections, fatigue, reduced muscle mass and strength, increased body fat, and mood changes. These are non-specific symptoms that can also result from other conditions, so laboratory confirmation is needed.
Which test checks testosterone levels?
Initial testing usually relies on morning total serum testosterone. Depending on the result, additional tests may be needed, such as SHBG, free testosterone, LH, FSH, or prolactin.
What time should a testosterone test be done?
Typically in the morning, since testosterone levels follow a normal daily variation and tend to be higher earlier in the day. Follow the specific instructions from your laboratory or treating physician.
Do I need to repeat the test if it comes back low?
Yes, in most cases. A low or borderline value is usually confirmed with a second morning measurement on a different day before any diagnosis is made or treatment decision is taken.
Does exercise increase testosterone?
Regular exercise, particularly resistance training, is associated with better overall hormonal and metabolic health and can help support normal testosterone levels, especially alongside weight loss. It does not cause a permanent, dramatic surge in testosterone.
Are there foods that increase testosterone?
No single food produces a clinically meaningful increase in testosterone in an otherwise healthy man. What matters more is an adequate, balanced diet overall — not one specific "miracle food".
Do zinc and vitamin D help?
Correcting a genuine deficiency in zinc, vitamin D, or magnesium can be beneficial. This does not mean that high-dose supplements raise testosterone in men without a documented deficiency — evidence for many "testosterone boosters" is limited.
Does testosterone therapy affect fertility?
Yes, significantly. Exogenous testosterone can suppress LH/FSH and sperm production, leading to reduced sperm counts or even azoospermia. Men who wish to have children need specific andrological evaluation before starting any such treatment.
When is testosterone therapy needed?
Replacement therapy (TRT) is considered only when compatible symptoms, repeatedly confirmed low testosterone, appropriate work-up of the underlying cause, and a benefit–risk assessment by the treating physician all come together. A single low value is not enough.
Related Topics
Low Testosterone or Hypogonadism Symptoms?
A single low testosterone value is not enough on its own for a diagnosis. Proper andrological evaluation combines symptoms, repeat hormonal testing, and investigation of the underlying cause. Book an appointment at our clinic in Rhodes.
References
- Bhasin S, et al. Testosterone Therapy in Men With Hypogonadism: Endocrine Society Clinical Practice Guideline. JCEM 2018 — PMID: 29562364
- Mulhall JP, et al. Evaluation and Management of Testosterone Deficiency: AUA Guideline. J Urol 2018 — PMID: 29601923
- EAU Guidelines on Sexual and Reproductive Health 2024 — uroweb.org
- Lincoff AM, et al. TRAVERSE: Cardiovascular Safety of Testosterone-Replacement Therapy. NEJM 2023 — PMID: 37326322
Medical Review
Dr. Marinos Vasilas
Urological Surgeon – Andrologist
Dr. Marinos Vasilas provides a personalized andrological approach to investigating and managing low testosterone at his clinic in Rhodes, following the guidelines of the Endocrine Society, the AUA, and the European Association of Urology (EAU).
Meet the Doctor