References UK clinical guidance from the NHS, the British HIV Association (BHIVA), and the British Association for Sexual Health and HIV (BASHH). Last updated: April 2026.
Testosterone is the main male sex hormone, produced mainly in the testes. Levels naturally vary between individuals and fluctuate throughout the day. While low testosterone gets most of the attention, high testosterone levels can also occur and can have several causes — some benign, some medical. Understanding what’s normal and what isn’t helps you decide when to seek advice.
Here’s a practical overview.
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What Is Normal?
Normal total testosterone levels in adult men typically range from about 10 to 30 nmol/L (300-1000 ng/dL), though reference ranges vary between labs. Levels are highest in the morning and decline during the day. Testosterone naturally peaks in the late teens and early 20s, then gradually declines with age.
Causes of High Testosterone
| Cause | Detail |
|---|---|
| Anabolic steroid use | The most common cause of unusually high levels in adult men |
| Testosterone replacement therapy | Prescribed TRT can sometimes push levels above normal |
| Testicular tumours | Rare, but some tumours produce testosterone |
| Adrenal tumours or hyperplasia | Can cause excess androgen production |
| Congenital adrenal hyperplasia | A genetic condition affecting hormone production |
| Natural variation | Some men naturally have higher levels within normal range |
Symptoms of High Testosterone
High testosterone doesn’t always cause obvious symptoms. When it does, they can include:
- Acne (particularly new or severe)
- Oily skin and hair
- Rapid muscle growth
- Mood changes — irritability, aggression
- Sleep disturbance
- Shrinking testicles (if caused by external testosterone)
- Breast tenderness or enlargement (gynaecomastia)
- Reduced sperm count and fertility
- High red blood cell count (polycythaemia)
Anabolic Steroid Use
The most common reason for markedly elevated testosterone in adult men in the UK is anabolic steroid use — usually for body-building or performance. Health consequences of steroid misuse include:
- Cardiovascular disease
- Liver problems
- Infertility (often long-lasting)
- Testicular shrinkage
- Mood and psychiatric issues
- Acne and hair loss
If you use anabolic steroids and want to stop safely, your GP or a specialist clinic can help. Many sexual health clinics offer supportive services including harm reduction advice.
Investigation
If high testosterone is found on a blood test, your doctor may:
- Repeat the test in the morning after an overnight fast
- Check other hormones (LH, FSH, prolactin, SHBG, oestradiol)
- Ask about steroid use, supplements and medications
- Examine for signs of tumours
- Consider imaging of testes or adrenal glands if needed
Treatment
Treatment depends on the cause:
- Stopping anabolic steroids
- Adjusting TRT dose
- Treating underlying tumours surgically
- Managing complications (blood viscosity, mood, fertility)
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Frequently Asked Questions
Is high testosterone dangerous?
It depends on the cause and level. Naturally high levels within normal range are fine. Markedly elevated levels from steroid use or tumours can cause serious health problems.
Can I reduce high testosterone naturally?
If levels are elevated due to external sources (steroids or prescribed TRT), stopping or adjusting those is the answer. Lifestyle changes have minimal effect on hormone levels once they’re significantly raised.
Does high testosterone affect fertility?
Excess testosterone suppresses the body’s natural hormone signals to produce sperm. This can cause temporary or long-lasting infertility, particularly in people using anabolic steroids.
Related reading
- How Accurate Are Rapid HIV Tests?
- Anonymous STI Testing: What It Means
- Are HIV Tests Accurate If You're on PrEP, PEP or ART?
- Are STI Blood Tests Accurate?
- Before You Get Intimate: Why You Should Ask About STI Testing
Sources
- NHS — Sexual health conditions
- BASHH — UK clinical guidelines for STI management
- British HIV Association (BHIVA) — HIV treatment guidelines
- Terrence Higgins Trust — sexual health information
- UK Health Security Agency — STI surveillance data
Steve Page is a recognised expert on Sexually Transmitted Diseases (STDs) and STD treatments, having published numerous articles in peer-reviewed journals and presented his research at conferences around the world. He has an in-depth understanding of the latest medical research on STDs, and is an advocate for the development of new treatments and protocols to improve the health of those affected. In addition to his research, he has dedicated his career to understanding the causes and symptoms of STDs, as well as how to best treat those impacted.
