What low testosterone actually feels like
The symptom pattern is broader than sex, and the sexual symptoms have a characteristic shape: desire falls first, and hardest.
| Domain | Typical symptoms |
|---|---|
| Sexual | Reduced libido, fewer spontaneous and morning erections, reduced ejaculate volume, less intense orgasm |
| Physical | Fatigue, loss of muscle mass and strength, increased body fat especially around the abdomen, reduced body hair |
| Cognitive and mood | Low mood, irritability, poor concentration, reduced motivation |
| Other | Hot flushes, reduced bone density, poor sleep quality |
Testing properly
- Two total testosterone measurements, taken in the morning — ideally before 10am — on separate days, fasting.
- Do not test during acute illness, after a poor night's sleep, or shortly after heavy exertion. All of these lower results transiently.
- If borderline, free or bioavailable testosterone plus SHBG can clarify, particularly in men with obesity or diabetes where SHBG is often low.
- LH and FSH distinguish a testicular problem (high LH) from a pituitary or hypothalamic one (low or normal LH with low testosterone).
- Prolactin where LH is low, since a prolactin-secreting pituitary tumour is an important reversible cause.
Causes worth fixing before treating
A meaningful proportion of low testosterone is secondary to something else — and that something else is often more treatable than the hormone itself.
- Obesity
- Fat tissue converts testosterone into oestrogen via aromatase. Significant weight loss raises testosterone without any medication.
- Obstructive sleep apnoea
- Fragmented sleep suppresses the nocturnal testosterone surge. Treating apnoea often improves both hormone levels and erections. See sleep apnoea and ED.
- Opioid medication
- Chronic opioid use is a well-documented and frequently missed cause of hypogonadism.
- Anabolic steroid use, past or present
- Exogenous androgens suppress the body's own production, sometimes for years after stopping. Be honest with your clinician about this — it changes the treatment plan entirely.
- Chronic illness, alcohol and severe stress
- All suppress the hypothalamic–pituitary–gonadal axis. Sometimes correcting them is enough.
If treatment is warranted
When symptoms and two confirmed low results line up, testosterone replacement is a legitimate treatment with a clear evidence base — but it is a commitment, not a trial run.
- Libido and energy typically respond within three to six weeks; erectile function, if it improves, can take months.
- It is frequently combined with a PDE5 inhibitor rather than replacing it.
- It suppresses sperm production. Raise fertility before you start — alternatives exist that preserve it.
- It requires ongoing monitoring of haematocrit and, in older men, PSA.
The full picture, including formulations, risks and monitoring, is in our testosterone therapy guide.
FAQ
Frequently asked questions
What is a normal testosterone level?
Reference ranges differ between laboratories, but a total testosterone below roughly 300 ng/dL on two morning tests is commonly used as the threshold for deficiency. Symptoms matter as much as the number.
Will testosterone fix my erections?
Only if you are genuinely deficient. In men with normal levels it does not improve erections and carries real risks.
Do testosterone boosters work?
There is no good evidence that over-the-counter boosters meaningfully raise testosterone. See our supplement evidence review.
Does masturbation lower testosterone?
No. This is a persistent internet myth with no supporting evidence.
Sources
What this is based on
We link to primary sources — clinical guidelines, regulator publications and peer-reviewed research — wherever possible. Links open on third-party sites we do not control.
- [01]American Urological Association. Testosterone Deficiency: AUA Guideline (2018).
- [02]Endocrine Society. Testosterone Therapy in Men With Hypogonadism — clinical practice guideline (2018).
- [03]National Institute of Diabetes and Digestive and Kidney Diseases. Definition & Facts for Erectile Dysfunction.