Social media sells testosterone as a shortcut to looking better. Here is what the hormone actually does, how it changes with age, and how clinicians assess it.
Social media has turned testosterone into a personality trait. Scroll long enough and you will see it sold as the fix for a soft jawline, a flat mood, a stubborn waistline and a general sense that life has lost its edge. Overseas, and increasingly through telehealth clinics, it is marketed directly to men, many of them in their twenties. In Australia, advertising prescription medicines to the public is generally prohibited. Marketing testosterone as a shortcut to a better physique also bypasses the assessment needed to establish whether treatment is appropriate.
The evidence does not support that story. Testosterone is a hormone with real, measurable effects on muscle, bone, mood, libido and red blood cells. What it is not is a cosmetic dial you turn up for a better face. And the idea that every man over 35 is quietly running low is not what the best research shows.
Understanding what testosterone does, and how it is assessed properly, is a far better place to start than any supplement ad or protocol video.
What testosterone actually does
Testosterone is the main androgen in men. Most of it is made in the testes, under signalling from the pituitary gland. It does several jobs at once, and the effects are not equally dramatic in every man.
Muscle and bone. Testosterone supports muscle protein synthesis and bone mineral density. Low levels over time are associated with reduced muscle mass and higher fracture risk.
Sexual function. It plays a role in libido, erectile function and sperm production. The relationship is not linear, and many other factors are involved.
Mood and energy. Low testosterone is associated with low mood, reduced motivation and fatigue. These symptoms overlap heavily with poor sleep, depression, thyroid disease and simply being worn out.
Metabolism and blood. Testosterone influences fat distribution, insulin sensitivity and red blood cell production. That last point matters clinically, because raising testosterone can thicken the blood.
Those effects do not make testosterone a cosmetic treatment or support the promise of a sharper jawline or a better face. That is the first thing the looksmaxxing trend gets wrong.
How testosterone really changes with age
In some population studies, total testosterone falls by roughly 1% a year from the 30s or 40s. Free testosterone falls a little faster. This is a slow drift, not a cliff.
Here is the part social media leaves out. Studies including the European Male Ageing Study and the Australian Healthy Man Study show that health and body composition strongly influence testosterone levels. In the Healthy Man Study, total testosterone did not vary significantly with age among men reporting very good or excellent health. Much of the decline tracks weight gain, chronic illness, poor sleep and medications, not birthdays. Ageing on its own is a weaker driver than the marketing suggests.
Normal is also a range, not a target. Testosterone results need to be interpreted alongside symptoms, the laboratory reference range and SHBG. A higher result within the reference range is not, by itself, evidence of better health or a reason to pursue treatment. A single number, read in isolation, tells you very little.
There is one more distinction that gets lost online. Primary hypogonadism means the testes themselves are not producing enough, so the pituitary pushes harder and its signalling hormones rise. Secondary hypogonadism means the signal from the pituitary or hypothalamus is insufficient to support normal testosterone production. That can come from a pituitary problem, but often comes from obesity, opioids, severe stress, poor sleep or past steroid use. The two look similar on a symptom checklist. They have different causes and different management, and telling them apart is a core part of the workup.
How clinicians assess it properly
A proper assessment is not one blood test ordered off the back of a TikTok video. It is a structured process.
Symptoms first
Symptoms are the reason to test, not an afterthought. Clinicians ask about libido, morning erections, energy, mood, sleep, changes in body composition and fertility plans. Depression, sleep apnoea and thyroid disease can look very similar, and treating the wrong thing wastes time and money.
Key markers
Testosterone peaks in the morning and drops after food. The standard is a fasting blood sample taken before 10am. A single low result is always repeated before any conclusion is drawn.
Marker | What it tells you |
|---|---|
Total (& free) testosterone | Total is the overall level in the blood, the starting point of any assessment. Free is the unbound fraction, usually calculated from total testosterone, SHBG and albumin, and most useful when SHBG is high or low. |
SHBG | Sex hormone binding globulin, which carries testosterone and decides how much is free. It runs low with excess weight and insulin resistance |
LH and FSH | In the setting of low testosterone, raised levels suggest a testicular cause. Low or inappropriately normal levels suggest a pituitary or hypothalamic cause. |
Prolactin | Raised levels can point to a pituitary problem that suppresses testosterone |
Oestradiol | Relevant in some settings, particularly with obesity |
Full blood count | Baseline haemoglobin and haematocrit, which help detect an excessive rise in red blood cells during treatment |
Metabolic markers | Glucose, HbA1c and lipids, because metabolic health and testosterone move together |
The SHBG row matters more than most people realise. Excess weight lowers SHBG, which drags total testosterone down while free testosterone may still be normal. Read total testosterone alone and a man can be labelled low when he is not.
This is general education about how assessment works. The right panel for any one person depends on their symptoms, history and first set of results.
Address reversible causes
When low testosterone is associated with obesity, medication effects or other potentially reversible factors, addressing those contributors is a central part of management. Established testicular or pituitary disease requires a different approach.
Sleep. Chronic short sleep and untreated sleep apnoea suppress testosterone. This is one of the most common and most fixable contributors.
Body composition. Excess fat lowers testosterone in several ways at once. It raises oestradiol, lowers SHBG and dulls the signal from the brain. Losing fat often raises testosterone without any medication.
Resistance training. Regular strength work supports muscle mass, insulin sensitivity and hormonal health.
Alcohol and opioids. Both suppress the hormonal axis. Cutting back can meaningfully change results.
Stress and mental health. Chronic stress and untreated depression act on the same system and often mimic the symptoms.
If symptoms persist despite addressing relevant contributors, and low testosterone is confirmed, further assessment and discussion of treatment may be appropriate.
The cost young men are not being told about
This is the part of the looksmaxxing conversation that worries clinicians most. Testosterone taken from outside the body tells the brain to stop signalling the testes. It can severely suppress fertility, sometimes reducing sperm production to undetectable levels.
A 24 year old starting it to look better may be compromising his future fertility. Recovery after stopping is common but not guaranteed, and it can take many months.
There is a related pattern in gym culture. Some young men who test low have suppressed their own production with anabolic steroids or other performance products bought online. When they stop, levels can stay low for months, and the symptoms that follow feed straight back into the next protocol video.
None of this features in the before and after photos.
The old fears and the current picture
For years, testosterone treatment carried a reputation for danger. Earlier studies raised concerns about heart attack and stroke risk, leading to considerable caution around treatment.
The picture has shifted. The TRAVERSE trial, published in 2023, followed more than 5,200 men aged 45 to 80 with low testosterone and existing heart risk. Treatment did not increase major cardiovascular events compared with placebo. But it was not a clean result. Treated men had more atrial fibrillation, more pulmonary embolism and more acute kidney injury.
An Australian trial adds another layer. T4DM followed about 1,000 men aged 50 to 74 with a large waist, lowish testosterone and early blood sugar problems. Everyone joined a lifestyle program. At two years, the proportion meeting the trial’s diabetes criterion was approximately 12% in the testosterone group and 21% in the placebo group, a relative reduction of about 40%. However, a haematocrit above 54% triggered safety action in approximately 22% of testosterone treated participants, compared with 1% receiving placebo. This finding does not, by itself, establish testosterone as routine treatment for diabetes prevention.
That is the honest summary. For men with genuinely low levels and real symptoms, the evidence is more reassuring than it once looked. It still comes with measurable risks, including thicker blood, raised blood pressure and suppressed fertility. It is not appropriate for men with certain prostate or breast cancer histories. And it does not fix a lifestyle problem.
This is why the looksmaxxing framing is unhelpful. It treats a medical assessment like a shopping decision. Testosterone sits inside a system, and changing one part without understanding the rest has downstream effects.
Why Australia is different
In parts of the world, testosterone is now marketed like a gym membership. Clinics advertise directly to young men, often with a quick online questionnaire and a single blood test.
The rules in Australia are different, and for good reason. Prescription medicines cannot be advertised to the public here. The Endocrine Society of Australia's position is that testosterone treatment is for genuine hypogonadism with a clear cause. It is not for low readings driven by ageing or weight alone. PBS subsidised testosterone also requires treatment by, or in consultation with, an appropriate specialist.
Some see that as overly cautious. The trial data above suggest it is closer to sensible. Whatever happens overseas, the starting point here is still a proper diagnosis, not a subscription.
FAQ
Can low testosterone cause weight gain?
Low testosterone is associated with more fat and less muscle, and excess fat in turn lowers testosterone. It runs both ways, which is why body composition is part of the assessment.
Will testosterone make me look better?
Testosterone is not an established treatment for improving facial appearance. In men with confirmed low levels, changes in body composition may occur, but that is a different question from whether treatment is medically appropriate.
Is testosterone treatment safe long term?
Evidence is more reassuring for appropriately selected men over the periods studied, but it does not establish safety over decades. TRAVERSE followed participants for an average of about 33 months. Treatment still requires an appropriate indication and ongoing monitoring.
Does it affect fertility?
Yes. Testosterone taken from outside the body suppresses sperm production. Anyone who may want children should raise this before any treatment is considered.
I feel tired. Should I get my testosterone checked?
Fatigue has many causes, and testosterone is only one of them. Whether testing makes sense depends on your symptoms and history, and that is a conversation to have with your own doctor.
Where to from here
From a longevity perspective, the aim is not to maximise a hormone result. It is to preserve function, address underlying disease and reduce avoidable risk over time. A low testosterone result may identify a condition that needs treatment, or it may reflect broader health factors that deserve attention. The value lies in understanding which situation applies.
General information, not individual medical advice. Speak to your own doctor.
References
Wu FC et al. Hypothalamic pituitary testicular axis disruptions in older men are differentially linked to age and modifiable risk factors: the European Male Aging Study. J Clin Endocrinol Metab. 2008.
Sartorius G et al. Serum testosterone, dihydrotestosterone and estradiol concentrations in older men self reporting very good health: the Healthy Man Study. Clin Endocrinol. 2012.
Lincoff AM et al. Cardiovascular safety of testosterone replacement therapy (TRAVERSE). N Engl J Med. 2023.
Wittert G et al. Testosterone treatment to prevent or revert type 2 diabetes in men enrolled in a lifestyle programme (T4DM). Lancet Diabetes Endocrinol. 2021.
Yeap BB et al. Endocrine Society of Australia position statement on male hypogonadism. Med J Aust. 2016.
