Last updated: October 2026.
Quick answer: Testosterone after 40 usually falls slowly, by about 1% a year on average, and many men stay in the normal range for life. Low testosterone is diagnosed only when symptoms such as low sex drive come with two morning blood tests below about 300 ng/dL. Body weight, sleep, alcohol and some medicines often matter more than age.
Testosterone after 40 is a common worry, and much of what men read about it comes from companies that sell tests, pills or prescriptions. The hormone does decline with age, but slowly, and age alone rarely explains a truly low result.
This guide covers what changes, what counts as normal, how to test and what the evidence says about raising levels. For the warning signs alone, see our list of low testosterone symptoms in men over 40.
Testosterone after 40 at a glance
| Question | Short answer |
|---|---|
| How fast does it fall? | About 1% a year on average from the 30s or 40s, with wide variation |
| Usual adult range | Roughly 300 to 1,000 ng/dL of total testosterone, depending on the lab |
| Usual threshold for low | Below about 300 ng/dL on two morning tests, with symptoms |
| Best time to test | Early morning, fasting, on two separate days |
| Most common reversible causes | Obesity, sleep apnea, type 2 diabetes, opioids, heavy drinking |
| Strongest lifestyle lever | Losing excess weight |
| Who is considered for TRT | Men with symptoms and consistently low levels, after a medical evaluation |
What happens to testosterone after 40?
Testosterone after 40 falls gradually, and there is no sudden drop. The figure most often cited is about 1% a year, starting in the 30s or 40s. It is an average across large groups, so it does not predict what happens to any one man.
Individual variation is wide. Some men in their 70s have levels typical of much younger men, and some men in their 40s test low. Healthy, lean older men tend to show smaller declines, which suggests that weight gain and illness explain part of what is blamed on age.
A carrier protein called SHBG also rises with age and binds testosterone, so the free, active share falls a little faster than the total.
What is a normal testosterone level for a man over 40?
A normal total testosterone level for an adult man is roughly 300 to 1,000 ng/dL, and the exact range depends on the laboratory. Read your result against the range printed on your own report.
Guidelines from the American Urological Association use a total testosterone below 300 ng/dL as a reasonable cut-off for low testosterone. The Endocrine Society asks for levels that are clearly and consistently low. Both require symptoms as well as numbers.
There is no separate official range for testosterone after 40. A number just under or just over the line is a reason to retest, not a diagnosis.
What are the symptoms of low testosterone?
The most telling symptoms are sexual: lower sex drive, fewer morning erections and erection problems. Tiredness and low mood are less specific, because they have many other causes.
- More specific: low libido, fewer spontaneous erections, erectile problems, loss of body hair, hot flashes, breast tenderness or enlargement, low bone density, infertility.
- Less specific: fatigue, low mood, poor concentration, loss of muscle and strength, more body fat, poor sleep.
Symptoms alone cannot confirm low testosterone after 40. Erection problems are more often linked to blood vessel health, as we explain in what causes erectile dysfunction.
What lowers testosterone besides age?
Obesity is the most common cause of low testosterone after 40, and several other conditions and medicines lower it too. Many of these causes can be treated, and levels may recover when they are.
| Cause | How it lowers testosterone | Can it be reversed? |
|---|---|---|
| Obesity | Lowers SHBG and dampens the brain signals that drive production | Often, with weight loss |
| Obstructive sleep apnea | Broken sleep and low oxygen at night | Partly; weight loss seems to matter most |
| Type 2 diabetes | Linked to lower levels, partly through excess weight | May improve with weight loss |
| Opioid painkillers | Long-term use suppresses hormone signals from the brain | Often, if the dose is changed under medical supervision |
| Heavy alcohol use | Affects the testicles and the liver | Often, with cutting down |
Steroid tablets, past anabolic steroid use and serious illness can also lower levels. Less often, the cause lies in the testicles or the pituitary gland, which is why a confirmed low result needs follow-up tests.
How do you test testosterone properly?
To check testosterone after 40, have blood drawn in the early morning, ideally fasting, and confirm a low result with a second test on a different day. Levels peak in the morning and fall during the day, and a meal can lower them for a few hours.
- Time it right. Have blood drawn in the early morning, before breakfast.
- Test when you are well. Illness and poor sleep can lower a result for a while.
- Repeat a low result. Many men who test low once are normal on the second test.
- Add follow-up tests if both are low. Doctors usually check LH and FSH, and often prolactin, SHBG or free testosterone.
Our guide to how to check testosterone levels covers the process step by step. A low result from a home kit still needs a lab test ordered by a doctor.
Can you raise testosterone after 40 without medication?
Yes, to a degree, and mainly when excess weight, poor sleep or heavy drinking is holding levels down. Lifestyle changes will not correct a disorder of the testicles or pituitary gland, and gains are modest in men who are already lean.
| Lever | What the evidence shows | Limits |
|---|---|---|
| Weight loss | The best-supported lever; bigger losses bring bigger rises in men with obesity | Little effect if you are not overweight |
| Resistance training | Builds muscle and reduces fat; raises testosterone briefly after sessions | Effect on resting levels is small and inconsistent |
| Sleep | Short sleep lowered daytime levels in small studies | Extra sleep beyond what you need has no proven benefit |
| Alcohol | Heavy drinking is linked to lower levels | The effect of light drinking is unclear |
These steps support heart health and sexual function whether or not the number moves. See natural ways to boost testosterone after 40 and our article on sleep and testosterone.
Do testosterone supplements work?
Most testosterone boosters have little good evidence behind them, and none replaces medical care for a confirmed deficiency. The studies are usually small and short.
- Vitamin D and zinc: correcting a real deficiency may help. Taking extra when your levels are adequate has not been shown to raise testosterone.
- Ashwagandha and fenugreek: a few small trials reported modest rises. Results are mixed and long-term safety data are thin.
- Proprietary blends: many hide the amount of each ingredient, so the dose cannot be compared with any study.
Supplements are not checked for effectiveness before sale. Tell your doctor what you take.
When is TRT considered, and what are the risks?
Testosterone replacement therapy (TRT) is considered for men who have symptoms and consistently low morning levels on two tests, once other causes have been checked. It is not recommended for normal ageing alone.
TRT may improve sex drive and, to a smaller extent, erections, mood and body composition. The main risks are:
- thicker blood (a raised red cell count), which needs regular blood tests
- lower sperm production, so it is not advised for men trying to conceive
- acne, breast tenderness and fluid retention
- possible worsening of untreated sleep apnea
- the need for prostate monitoring with PSA tests
Treatment is usually long term. Read TRT: is it right for you? before you decide, and check our list of TRT clinic red flags if you are looking at online providers.
When should you see a doctor?
See a doctor if sexual symptoms, unexplained fatigue or low mood last more than a few weeks. Do not start a hormone product on your own. Book an appointment promptly for any of these:
- erection problems, especially with diabetes or high blood pressure
- breast enlargement, a breast lump or nipple discharge
- a lump, swelling or shrinkage in a testicle
- a broken bone after a minor fall, or loss of height
- difficulty conceiving after a year of trying
- headaches with changes in vision
- loud snoring with pauses in breathing
Seek urgent help for chest pain, sudden breathlessness, a painful swollen leg or thoughts of self-harm.
Testosterone after 40 FAQ
Does testosterone drop suddenly after 40?
No. Testosterone after 40 falls gradually, by about 1% a year on average. There is no sudden drop, and the rate differs widely between men depending on weight, health and medicines.
What is a normal testosterone level for a 45-year-old man?
Most labs report a normal adult range of roughly 300 to 1,000 ng/dL of total testosterone. There is no separate official range by age, so compare your result with the range on your lab report.
What testosterone level is considered low?
Guidelines commonly use a total testosterone below about 300 ng/dL, measured in the early morning on two separate days. A diagnosis also requires symptoms, such as low sex drive or fewer morning erections.
What time of day should I test my testosterone?
Test in the early morning, ideally before eating. Testosterone peaks in the morning and falls through the day, and a meal can lower it for a few hours.
Can losing weight raise testosterone after 40?
Yes, in men who carry excess weight. Weight loss is the best-supported way to raise testosterone after 40, and larger losses tend to bring larger rises. It has little effect in lean men.
Do testosterone boosters work for men over 40?
Evidence is weak for most of them. Vitamin D or zinc may help men who are deficient. A few small trials of herbs such as ashwagandha reported modest rises, but results are mixed.
Is low testosterone after 40 a normal part of ageing?
A slow decline is normal. A level clearly below the reference range, together with symptoms, is not explained by age alone and should be evaluated by a doctor for other causes.
Is TRT safe for men over 40?
TRT can be appropriate for men with a confirmed deficiency. Risks include thicker blood, reduced fertility, acne and possible worsening of sleep apnea. It requires regular blood tests and prostate monitoring by a doctor.
Bottom line
Testosterone after 40 declines slowly and unevenly, and most men never need treatment for it. If you have symptoms, get two early-morning blood tests and a proper evaluation before you buy anything. Weight, sleep and alcohol are the first things to address. TRT is an option for confirmed deficiency, with risks and long-term monitoring.
References
- Endocrine Society: Testosterone Therapy in Men With Hypogonadism, clinical practice guideline.
- American Urological Association: Clinical guidelines, including Testosterone Deficiency.
- MedlinePlus: Testosterone Levels Test.
- MedlinePlus: Sleep Apnea.
- NIH Office of Dietary Supplements: Vitamin D fact sheet.
- NIH Office of Dietary Supplements: Zinc fact sheet.
This article is for information only and is not medical advice. Supplements are not intended to diagnose, treat, cure or prevent any disease.