By Dr. Ali Aldibbiat — MD, PhD, FRCP (London & Edinburgh), FACE. Consultant Endocrinologist, Newcastle Vitality Clinic, Jumeirah, Dubai.
A man in his forties is tired, his motivation has flattened, his gym progress has stalled and his libido has faded. He orders a testosterone test online, gives a blood sample at four in the afternoon, and receives a result at the lower end of the range. Within a week he is on testosterone.
Almost everything about that sequence is wrong — and the outcome may well be a man on lifelong hormone therapy for a condition he never had, while the thing actually causing his symptoms goes untreated.
What low testosterone actually feels like
The symptoms divide into two groups, and the distinction matters enormously.
Reasonably specific to testosterone deficiency:
- Reduced frequency of morning erections
- Reduced sexual desire
- Erectile difficulty, particularly alongside the above
- Loss of body and facial hair, and reduced need to shave
- Small or soft testes
- Breast tissue development or tenderness (gynaecomastia)
- Reduced fertility, or difficulty conceiving
- Hot flushes, in more severe deficiency
Non-specific, and heavily over-attributed:
- Fatigue
- Low mood
- Poor concentration
- Reduced muscle mass and strength
- Increased body fat
- Poor sleep
The second list is real — these symptoms do occur in testosterone deficiency. But they occur in a great many other conditions too, including depression, sleep apnoea, iron deficiency, thyroid disease, poorly controlled diabetes, chronic stress and simple sleep deprivation.
Direct-to-consumer testosterone services are built on that overlap. A questionnaire asking about fatigue, motivation and libido will identify a very large proportion of men over 40 as candidates, whatever their hormonal status.
If your symptoms are entirely from the second list, testosterone deficiency is possible but statistically unlikely to be the explanation, and a proper assessment is more likely to help you than a prescription.
Why most testosterone tests are done wrong
This is the most useful section in this article, and if you take one thing from it, take this.
Testosterone must be measured in the morning, fasting. Testosterone follows a diurnal rhythm, peaking in the early morning and falling through the day. The reference ranges laboratories use were derived from morning samples. An afternoon sample can read 20–30% lower than the same man’s morning value. A “low” afternoon result may simply be a normal man tested at the wrong time. The correct window is 07:00 to 11:00, fasting.
A single low result is not a diagnosis. Testosterone varies day to day, and acute illness, poor sleep or recent intense exercise all lower it transiently. Guidelines require a low result to be confirmed on a second, separate morning sample before any diagnosis is made. One test is a signal; two make a finding.
Total testosterone alone is often misleading. Most circulating testosterone is bound to sex hormone binding globulin (SHBG) and is not biologically available. What matters to your tissues is the free fraction. SHBG is altered by many common conditions:
- Obesity, insulin resistance and type 2 diabetes lower SHBG, so total testosterone reads low while free testosterone may be adequate
- Ageing, hyperthyroidism and liver disease raise SHBG, so total testosterone may look reassuring while free testosterone is genuinely low
This is why SHBG should be measured alongside total testosterone, with free testosterone calculated — particularly in men who are overweight, diabetic, or over 60. Without it, you are interpreting a number that may not mean what it appears to.
Assay quality matters. Immunoassays are less accurate at the low end of the range, where the clinical decision is being made. Where available, mass spectrometry is preferred.
A single afternoon total testosterone — which is what most walk-in health packages provide — is close to uninterpretable on its own.
The tests that must accompany it
Finding a low testosterone is the beginning of the assessment, not the end. The next question is why, and the answer changes the treatment entirely.
LH and FSH. These separate the two fundamental categories. High LH and FSH with low testosterone indicates primary hypogonadism — the testes are not responding despite the brain signalling correctly. Low or inappropriately normal LH and FSH with low testosterone indicates secondary hypogonadism — the signal from the pituitary is inadequate, and something at that level needs explaining.
Prolactin. An elevated prolactin can indicate a pituitary tumour — uncommon, entirely treatable, and disastrous to miss. Any man with secondary hypogonadism needs this checked.
Ferritin and iron studies. Haemochromatosis causes hypogonadism through iron deposition in the pituitary and testes, and it is a genetic condition with implications for the whole family.
HbA1c and fasting glucose. Type 2 diabetes and low testosterone are closely linked in both directions.
Thyroid function. Both over- and underactive thyroid affect testosterone and cause overlapping symptoms.
Full blood count including haematocrit. Essential as a baseline before any treatment, since testosterone raises red cell mass.
PSA, in men over 40, as a baseline before treatment.
Vitamin D, commonly deficient here, and relevant to fatigue and muscle function.
Each result changes what happens next. That reasoning is what a specialist adds, and it is precisely what an online questionnaire cannot provide.
The reversible causes you must exclude first
This is where I most often part company with commercial testosterone services, because in a substantial proportion of men, low testosterone is a consequence of something else — and treating that something else raises testosterone without any hormone therapy at all.
Obesity. Adipose tissue contains aromatase, which converts testosterone to oestradiol; visceral fat also suppresses pituitary signalling. The result is genuinely low testosterone. Significant weight loss raises testosterone measurably, and modern weight management makes that far more achievable than it once was. See how GLP-1 weight loss options compare (/weight-loss-injections-dubai-semaglutide-tirzepatide-oral-glp1/).
Obstructive sleep apnoea. Common, frequently undiagnosed, strongly associated with low testosterone, and independently responsible for fatigue, low mood and poor concentration. Treating it addresses several problems simultaneously.
Uncontrolled type 2 diabetes.
Opioid medications, which suppress the hypothalamic-pituitary-gonadal axis powerfully and are a very common overlooked cause.
Glucocorticoids, systemic or high-dose inhaled.
Excess alcohol.
Previous or current anabolic steroid use. More common than most patients disclose initially. Exogenous androgens suppress the axis, sometimes for a long time after stopping.
Severe stress, chronic sleep deprivation, and extreme energy deficit — including in men training hard while eating too little.
Treating the cause rather than the number is the difference between medicine and product sales. In a man with a BMI of 34, untreated sleep apnoea and a testosterone at the lower limit, starting TRT would treat the number while leaving everything actually harming his health untouched.
“Age-related” decline and what the regulators say
Testosterone declines modestly with age — around 1% per year from the fourth decade in most men. Whether that decline requires treatment in the absence of a specific cause remains genuinely debated.
The regulatory position is unambiguous. When the FDA revised testosterone product labelling in February 2025, it explicitly retained the Limitation of Use: these products are indicated for men with clinically low testosterone accompanied by an associated medical condition, not for low testosterone due to ageing alone.
That does not mean an older man with genuine symptoms and confirmed low testosterone should be dismissed. It does mean that “my testosterone is lower than it was at 25” is not by itself a diagnosis, and that anyone treating it as one is going beyond what the evidence and the licence support.
What a proper assessment involves
At NVC, assessment of suspected testosterone deficiency includes a full history covering symptoms, medications, sleep, substance and steroid use, and fertility intentions; examination including testicular examination, gynaecomastia assessment, waist circumference and blood pressure; two morning fasting testosterone measurements with SHBG and calculated free testosterone; the full accompanying panel above; and a clear explanation of what the results mean and what the options are — which may or may not include testosterone.
If treatment is appropriate, it is started with a monitoring schedule agreed in advance. If it is not, you will be told why, and what will help instead.
Frequently asked questions
What is a normal testosterone level for my age? Reference ranges vary between laboratories and assays, and interpretation depends on SHBG and free testosterone as well as the total. A result should never be interpreted without knowing the sampling time, whether it was fasting, and whether it has been confirmed on a second morning sample.
What time of day should a testosterone test be taken? Between 07:00 and 11:00, fasting. Testosterone falls through the day, and afternoon samples are commonly misinterpreted as low.
Can low testosterone be reversed without TRT? Often, yes — particularly where the cause is obesity, sleep apnoea, uncontrolled diabetes, opioid use or excess alcohol. Addressing these can raise testosterone into the normal range without hormone therapy.
Does losing weight increase testosterone? Yes. Significant weight loss raises testosterone in men with obesity-related hypogonadism, because reducing fat mass reduces the conversion of testosterone to oestradiol and improves pituitary signalling.
Do I need a referral for a testosterone test in Dubai? You can access testing directly, but a result without proper interpretation causes more problems than it solves. What matters is that testing is done correctly and read in the context of a full assessment.
Get the diagnosis right before you get the prescription. A single testosterone number cannot tell you whether you need treatment. Book a comprehensive assessment with Dr. Ali Aldibbiat, Consultant Endocrinologist, at Newcastle Vitality Clinic, Jumeirah.