Testosterone: How to Increase Levels Safely

Testosterone is more than just a "libido hormone." It influences libido, morning erections, spermatogenesis, body composition, bone tissue, mood, and red blood cell production. However, in clinical practice, what's important isn't the low test result itself, but the presence of testosterone deficiency syndrome, or hypogonadism. This is why the modern approach is built around the question of "is there a confirmed disease and its cause," rather than the idea of "increasing hormone levels by any means necessary." [1]

The core message of all major guidelines is the same: a man is not considered ill simply because his values are below average. The Endocrine Society of the United States requires symptoms and consistently low values, the American Urological Association uses a threshold below 300 ng/dL as a reasonable diagnostic guideline, and the European Association of Urology emphasizes symptoms and repeated values below 12 nmol/L in men with late-onset hypogonadism. This is not a contradiction, but a reflection of the fact that laboratory methods, populations, and clinical objectives vary across guidelines. [2]

For reference, it's useful to remember the reference range for healthy, non-obese men aged 19-39 years, standardized by the US Centers for Disease Control and Prevention: 264-916 ng/dL. However, this range should not be mechanically used as the sole threshold for treatment. In real-life practice, a physician will evaluate symptoms, repeat morning blood tests, sex hormone-binding globulin, and the possible cause of the decrease. [3]

When Low Testosterone Is a Disease, Not Just a Number

A diagnosis is made when there are characteristic complaints and biochemical confirmation. The most specific symptoms are considered to be decreased libido, erectile dysfunction, and a decrease in the frequency of spontaneous erections, especially morning ones. Physical and psychological complaints, such as fatigue, decreased energy, worsening mood, and decreased muscle strength, are also important, but they are much less specific and can occur in dozens of other conditions. [4]

Therefore, modern medicine has abandoned the popular but incorrect approach of immediately prescribing testosterone to men with fatigue, excess weight, or a bad mood. The correct algorithm is different: first, the symptoms are clarified, then morning tests are repeated, then the primary or secondary cause is sought, and only then treatment is discussed. [5]

Table 1. How different documents interpret testosterone deficiency

Source	What is considered important
The Endocrine Society of America	Symptoms plus definitely and repeatedly low testosterone
American Urological Association	A threshold below 300 ng/dL as reasonable support for the diagnosis
European Association of Urology	In men with symptoms of late hypogonadism, a level below 12 nmol/L is a guideline.
Harmonized reference range for healthy men aged 19-39 years	264-916 ng/dL for standardized assays

The table is compiled according to international guidelines and standardized reference ranges. [6]

Causes of decreased testosterone

The causes are divided into two broad groups. The first is primary hypogonadism, when the problem is located at the testicular level. The second is secondary, when stimulation from the hypothalamus and pituitary gland is impaired. There is also a functional variant, in which the axis is reversibly suppressed by obesity, insulin resistance, chronic diseases, certain medications, and inflammation. It is the functional variant that is most common today. [7]

Obesity is considered the most important risk factor for testosterone deficiency in men. Excess adipose tissue enhances androgen aromatization, increases inflammation, affects leptin and insulin, and thereby suppresses the hypothalamic-pituitary-gonadal axis. Importantly, this form of testosterone deficiency can be at least partially reversible with significant weight loss. [8]

Among drug-induced causes, opioids and glucocorticosteroids are particularly significant. Furthermore, testosterone levels cannot be reliably assessed during acute illness, severe stress, or immediately following a serious infection, as these conditions can lead to a transient functional decline. Such testing easily leads to overdiagnosis and unnecessary treatment. [9]

Table 2. Common causes of decreased testosterone

Group of reasons	Examples
Primary, testicular	Genetic syndromes, history of cryptorchidism, chemotherapy, radiation therapy, toxic testicular injury
Secondary, hypothalamic-pituitary	Hyperprolactinemia, pituitary tumors, hypopituitarism, functional axis suppression
Functional and reversible	Obesity, insulin resistance, chronic inflammation, severe diseases
Medicinal	Opioids, glucocorticosteroids, anabolic steroids after withdrawal
Situational	Acute infections, severe stress, improper preparation for the test

The table is compiled from guidelines and reviews on male hypogonadism and obesity. [10]

Symptoms

The most clinically significant and specific symptoms are sexual ones. These include decreased libido, erectile dysfunction, and a decrease in the number of morning erections. These complaints are the ones that best correlate with true testosterone deficiency and are the ones that a doctor will focus on first. [11]

Physical symptoms are also important, but do not alone confirm the diagnosis. These include decreased activity, decreased exercise tolerance, increased fat mass, decreased muscle mass, and sometimes decreased bone mineral density and anemia. Some men also experience depressed mood, decreased motivation, and a feeling of "constant exhaustion," but these symptoms are often also associated with depression, sleep disturbances, obesity, and chronic diseases. [12]

Table 3. What symptoms are most suspicious?

Degree of specificity	Symptoms
More specific	Decreased libido, erectile dysfunction, decreased morning erections
Less specific	Fatigue, decreased energy, mood swings, decreased strength, fat gain
Late and complicated manifestations	Decreased bone density, anemia, marked decrease in muscle mass

The table is based on the recommendations of the European Association of Urology and the American Urological Association. [13]

Diagnostics

The first step isn't treatment, but proper testing. The European Association of Urologists recommends measuring total testosterone in the morning, between 7:00 and 11:00 a.m., on an empty stomach, and repeating the test at least twice if the result is abnormal or borderline. The Endocrine Society of the United States also recommends repeating morning measurements and using accurate measurement methods. [14]

The second step is to determine whether sex hormone-binding globulin (SHBG) is distorting the picture. In obesity, aging, liver disease, thyroid dysfunction, and certain other conditions, total testosterone can be misleading. In such situations, free testosterone is estimated using a calculation method or a reliable laboratory method, and direct, inaccurate immunoassays for free testosterone are not recommended. [15]

The third step is to determine the source of the problem. This is done by measuring luteinizing and follicle-stimulating hormones, and if a secondary variant is suspected, prolactin. If prolactin levels are persistently elevated or there are symptoms of pituitary damage, such as headaches and visual disturbances, an MRI of the pituitary gland is indicated. [16]

Table 4. Basic diagnostic algorithm

Stage	What to do	For what
1	Measure total testosterone twice in the morning on an empty stomach	Exclude random and transient reduction
2	Assess sex hormone-binding globulin and, if necessary, free testosterone	Clarify the actual androgen status
3	Determine luteinizing and follicle-stimulating hormones	Distinguish between primary and secondary hypogonadism
4	Determine prolactin with low or normal luteinizing hormone and symptoms	Exclude hyperprolactinemia and pituitary causes
5	Assess concomitant diseases, medications, body weight and waist circumference	Find reversible causes

The table is compiled according to international recommendations. [17]

How to safely increase levels without replacement therapy

If a man is obese or has significant metabolic disorders, the first line of treatment should be weight loss and lifestyle changes. The European Association of Urology explicitly states that this should be the initial strategy for overweight men with hypogonadism. According to reviews and meta-analyses, weight loss is accompanied by an increase in testosterone, with the magnitude of the increase related to the amount of weight lost. [18]

It's important not to promise miracles, however. Guidelines emphasize that after diet and physical activity, testosterone increases are often modest, often in the range of 1-2 nmol/L, although for some men, the effect may be much more noticeable after significant weight loss. Simply put, lifestyle isn't an "instant booster," but the best way to restore the hormonal axis when functional decline occurs and simultaneously improve overall health. [19]

Sleep also matters. Survey data show that sleep loss and short sleep duration are associated with decreased testosterone levels, and hormone secretion itself is largely dependent on sleep. Therefore, normalizing sleep is not a secondary recommendation, but rather part of a safe, basic approach. [20]

Table 5. What really helps increase testosterone safely

Approach	What is known
Weight loss	The most compelling non-drug strategy for obesity
Physical activity	Improves metabolism and symptoms, sometimes moderately increases testosterone
Normalization of sleep	Important for maintaining normal testosterone secretion
Correction of the cause	Discontinuation or replacement of problematic medications, treatment of hyperprolactinemia, therapy of concomitant diseases
Treatment of sleep apnea and metabolic disorders	Important first of all for safety and the overall clinical picture

The table is based on reviews, meta-analyses, and guidelines on male hypogonadism.[21]

When is testosterone replacement therapy needed?

Replacement therapy is not considered for every man with a "low test," but for those with symptoms and a recurring deficiency. The Endocrine Society and the American Urological Association agree that the goal of treatment is to improve the symptoms of hypogonadism, not just to improve the number. Patients are advised in advance that the best evidence concerns libido, erectile function, anemia, bone density, lean mass, and some depressive symptoms, while the impact on energy, cognitive function, and quality of life is less certain. [22]

The therapy should not be used for weight loss, improving athletic performance, treating type 2 diabetes for glycemic control, or as an anti-aging treatment. The Endocrine Society specifically discourages the use of testosterone to improve glycemic control in men with type 2 diabetes, and the US Food and Drug Administration (FDA) in 2025 retained the restriction on use in cases of age-related decline in testosterone levels without an established medical reason. [23]

In terms of therapy modalities, the choice is between gels, injections, oral options, and, less commonly, other delivery systems. Gels are convenient and easily controlled, but carry the risk of drug transfer through close skin contact. Injectable forms are effective, but more often fluctuate in concentration and are associated with a higher risk of elevated hematocrit, especially compared to topical forms. Oral forms exist, but for some of them, the regulator specifically notes the concern of increased blood pressure. [24]

Table 6. Main treatment options

Option	Pros	Cons
Gels	Smooth profile, convenient dose titration	Risk of transfer to the skin of other people, daily regimen is required
Injections	Pronounced effect, convenient for some patients	Fluctuations in levels, hematocrit often increases
Oral forms	Do not require injections or application to the skin	Not suitable for everyone, for some forms pressure control is important
Gonadotropins for secondary hypogonadism and the desire to have children	Preserve or restore fertility	The scheme is more complex and requires a specialist.
Selective estrogen receptor modulators and aromatase inhibitors	Sometimes endogenous testosterone is increased	Off-label use, less evidence, risks

The table is compiled according to the recommendations of the European Association of Urology, the Endocrine Society and the guidelines on male infertility. [25]

Safety, contraindications and monitoring

There are situations when testosterone should not be prescribed or should be done with extreme caution. The Endocrine Society recommends against initiating therapy in men who are planning to conceive in the near future, those with prostate or breast cancer, elevated hematocrit, untreated severe obstructive sleep apnea, severe lower urinary tract symptoms, uncontrolled heart failure, recent myocardial infarction or stroke, and thrombophilia. The European Association of Urology classifies an active desire to have children and a hematocrit of 54% or higher as absolute contraindications. [26]

The most common adverse effect of therapy is erythrocytosis, or an increase in hematocrit. Both the Endocrine Society and the European Association of Urology recommend that hematocrit be measured before treatment, then after 3-6 months, and then annually. If values exceed 54%, therapy should be adjusted or temporarily discontinued. In men at high risk, hematocrit elevations are monitored more frequently. [27]

The issue of cardiovascular safety has become clearer in recent years, but has not disappeared entirely. In the TRAVERSE study in 5,246 men with confirmed hypogonadism and high or existing cardiovascular risk, the incidence of major cardiovascular events was 7.0% in the testosterone group versus 7.3% in the placebo group, meaning the therapy was no worse than placebo in this regard. At the same time, European guidelines note a signal about a slightly higher incidence of atrial fibrillation, acute kidney injury, and pulmonary embolism, so monitoring remains mandatory. In 2025, the US regulator updated the drug labeling: it retained the restriction on use in cases of age-related decline without an established cause, removed the old warning about increased cardiovascular risk as a class effect, but required that data on increased blood pressure be taken into account. [28]

Table 7. What needs to be monitored during therapy

Indicator	When to control
Total testosterone	3-6 months after the start, then according to the regimen and form of the drug
Hemoglobin and hematocrit	Before treatment, after 3-6 months, then annually
Prostate-specific antigen and urologic evaluation	Before treatment according to indications and further in selected patients
Symptoms and side effects	On every visit
Metabolic profile and bone density as indicated	Individually, especially in cases of functional hypogonadism and osteoporosis

The table is based on the guidelines of the Endocrine Society and the European Association of Urology.[29]

Fertility and conception planning

This is one of the most important sections, often overlooked in popular articles. Exogenous testosterone suppresses the hypothalamic-pituitary signal, causing sperm production to decrease and sometimes stop completely, leading to azoospermia. Therefore, men who are concerned about current or future fatherhood should not be prescribed conventional testosterone replacement therapy. [30]

If such a patient does have secondary hypogonadism, gonadotropins are considered the standard. Male infertility guidelines indicate that for hypogonadotropic hypogonadism, treatment typically begins with human chorionic gonadotropin, monitoring the testosterone response, and then, if necessary, adding follicle-stimulating hormone to optimize spermatogenesis. Selective estrogen receptor modulators and aromatase inhibitors are sometimes used, but these options have a lesser evidence base and are often used off-label. [31]

What doesn't work or is dangerous

A man with normal testosterone levels should not be treated simply because he wants more energy, muscle, or "virility." Guidelines explicitly prohibit the use of testosterone in eugonadal men and do not support its use for weight loss, cognitive enhancement, strength, or anti-aging. [32]

Dietary supplements that promise a "natural testosterone boost" should also be approached with caution. Unless there is a confirmed zinc or vitamin D deficiency, or another specific cause, such regimens should not be expected to produce significant results. It is far more important to address obesity, sleep deprivation, alcohol abuse, and the use of anabolic steroids or suppressive medications. [33]

Frequently Asked Questions

Can a diagnosis be made based on just one test?
No. Both the Endocrine Society and the European Association of Urology require a repeat morning measurement, and a diagnosis is made only if symptoms are combined with persistently low values. [34]

What level is considered low?
There is no universal "magic number." The American Urological Association uses a threshold below 300 ng/dL as reasonable support for diagnosis, the European Urological Association uses a threshold below 12 nmol/L in symptomatic men, and the standardized reference range for healthy young men is 264–916 ng/dL. [35]

Is it possible to simply lose weight and avoid therapy?
In many cases of functional hypogonadism associated with obesity, the answer is yes, at least partially. Weight loss is considered the first line of treatment, and the greater and more sustained the weight loss, the greater the chance of testosterone levels increasing. [36]

Does testosterone improve erections?
Sometimes yes, but mostly in men with proven hypogonadism. Libido and some sexual symptoms are most predictably improved; in severe erectile dysfunction, a combination with other treatments is often required. [37]

Is testosterone safe for the heart?
Current data are more reassuring than they were 10 years ago. The TRAVERSE study showed no increase in major cardiovascular events compared to placebo in men with confirmed hypogonadism, but therapy still requires patient selection and monitoring, particularly for hematocrit, blood pressure, and thrombotic risk factors. [38]

Is it possible to take testosterone if you want to have children?
Generally, no. Exogenous testosterone suppresses spermatogenesis and can lead to azoospermia. In this situation, gonadotropins and other special regimens should be discussed with an andrologist or reproductive specialist. [39]

Key points from experts

Shalender Bhasin, Professor of Medicine at Harvard Medical School and Chair of the Endocrine Society's Testosterone Guidelines Panel, concluded: "Treatment should be focused not on a low testosterone level, but on confirmed hypogonadism with symptoms, repeated low levels, and a clear follow-up plan." This approach protects against both overdiagnosis and inappropriate hormone prescriptions. [40]

John P. Mulhall, Chairman of the American Urological Association Panel on Testosterone Deficiency, Memorial Sloan Kettering Cancer Center, said his position is particularly relevant to practice: a threshold below 300 ng/dL is useful as a clinical guideline, but the decision must always take into account symptoms, risks, safety, and the issue of fertility preservation. [41]

Channa Jayasena, Clinical Professor of Reproductive Endocrinology and Andrology at Imperial College London, is the author of the British Society of Endocrinology guidelines. His contribution is particularly notable in that current British guidelines emphasize a multidisciplinary approach: first seeking reversible causes, especially obesity and drug-induced axis suppression, and then moving on to hormonal therapy. [42]

Conclusion

Safely increasing testosterone levels begins not with an injection or supplement, but with a proper diagnosis. If the decrease is due to obesity, sleep deprivation, medications, or metabolic disorders, the first line of action should be correcting the underlying cause and lifestyle. If true hypogonadism is present, therapy is possible, but only after confirming the diagnosis, discussing contraindications, and developing a monitoring plan. [43]

The most common mistake in this area is trying to treat age, fatigue, or dissatisfaction with body shape with testosterone. The most correct strategy is to distinguish functional decline from organic hypogonadism, not forgetting fertility, and managing the patient to improve not only test results but also actual health. [44]