Getting tested properly
Testosterone peaks in the morning and falls through the day, so a valid test is drawn before 10am. It also needs to be repeated — a single low reading is not a diagnosis, because levels swing with illness, poor sleep, and stress.
Most guidelines treat total testosterone below roughly 300 ng/dL, confirmed on two separate morning samples, as low. Numbers alone are not enough either: the diagnosis requires symptoms as well — low libido, fatigue, loss of muscle, low mood, poor concentration.
A clinic that prescribes testosterone from one afternoon blood draw, or from a questionnaire with no blood draw at all, is not practising to standard. This is the most common shortcut in the direct-to-consumer men's health market.
What it will and will not fix
When levels are genuinely low, replacement reliably improves sex drive, energy, mood and body composition. Those are real gains and men notice them.
Erections are less predictable. Testosterone drives desire more than it drives the plumbing, and if your arteries are the problem, a hormone will not unclog them. What it does do usefully is improve how well pills work — men with low testosterone who failed sildenafil sometimes respond once their level is corrected.
The monitoring you must not skip
Testosterone raises your red blood cell count. Pushed too high, thick blood raises clot risk, so haematocrit needs checking at baseline, then periodically. This is the most common reason to reduce a dose.
PSA and a prostate assessment are checked before starting and monitored after. Testosterone does not appear to cause prostate cancer, but it can accelerate one that is already present and undetected.
It suppresses your own production. Your testicles shrink and sperm production drops, often to zero. For men who might still want children this is the decisive issue, and it does not always fully reverse after stopping.
On cardiovascular safety, the large TRAVERSE trial published in 2023 found no increase in major cardiac events for men with low testosterone and existing heart risk. That was reassuring. Labels still carry warnings about blood pressure increases, so it remains something to monitor rather than ignore.
Side effects
Common, and usually manageable
- Acne and oilier skin
- Fluid retention
- Shrinking of the testicles
- Breast tenderness or enlargement
- Gel forms can transfer to a partner or child by skin contact — cover the area
Get medical help straight away
- Thickened blood from a rising red cell count, raising clot risk
- Worsening of untreated sleep apnoea
- Infertility, which is not always reversible
- Acceleration of an existing, undiagnosed prostate cancer
Common questions
My level is 320 and I feel terrible. Can I still be treated?
Possibly. The cutoff is a guideline, not a wall, and free testosterone or SHBG may tell a fuller story. That is a conversation for an endocrinologist or urologist rather than a subscription clinic.
Are the online testosterone clinics legitimate?
Some are. The test is whether they require two morning blood draws before prescribing, and whether they schedule follow-up haematocrit and PSA monitoring. If either is missing, look elsewhere.