Sven Wombwell
Article by: Sven Wombwell
Estimated 8 minutes read

The hormone testosterone is vital for men as they age. During puberty, it's responsible for building muscle, producing facial and body hair, deepening the voice, and sexual desire. As they age, it helps to regulate weight, control cholesterol levels, and maintain energy and mood. But throughout life, hormone levels fluctuate, with many men wondering what are average testosterone levels by age.

As a teen, testosterone levels are at their highest level, with a decline beginning in the mid-thirties and continuing to drop about 1-2% each year. Studies show ( 1) that testosterone levels can depend on several factors, including health conditions, genetics, and lifestyle factors, so determining testosterone levels by age isn't as simple as it seems.

That said, some average testosterone levels for healthy men can be used as a baseline. Still, it's always best to consult your medical professional for accurate information regarding your health.

What are the Average Testosterone levels by age?

Testosterone levels are typically measured in nanograms per deciliter (ng/dL), and according to Mount Sinai (2), a healthy testosterone range is between 300 to 1,000 ng/dL. When teen boys are at their peak, at about age 19, they can have testosterone levels of 300 ng/dL and higher, with levels staying in that range until they hit their thirties, when levels may begin to decline.

According to studies,(3) (4) average men's testosterone levels by age are as follows:

AgeTestosterone level
20 - 24-year-old males409 - 558 ng/dL
25 - 29-year-old males 413 - 575 ng/dL
30 - 34-year-old males359 - 498 ng/dL
35 - 39-year-old males352 -478 ng/dL
40 - 44-year-old males350 - 473 ng/dL
Average testosterone levels by age.

According to another study (5), there's been a consistent decline in testosterone levels in general over the last several decades and a 20% decline in young adult men. Currently, a sign of low testosterone in men is under 300 ng/dL. 

The fact is that labeling any hormone level as normal is fruitless. Studies are meant to provide insight, but they don't tell you what's best for your situation. Normal hormone levels don't mean the patient won't have symptoms, as receptor site resistance, among other factors, can cause symptoms despite normal levels.

The Importance of Healthy Testosterone Levels 

Optimal (not normal) testosterone levels help control cholesterol, lipids and glucose, but they also protect our bones, brain, and memory. So, when testosterone levels begin to decline, you can feel it in various ways. 

You may be experiencing brain fog and can't remember things, or you may see your cholesterol rise despite eating whole foods. Other symptoms can include low energy levels that interfere with performing everyday tasks or a sex drive that has diminished, putting your relationship at risk. 

Although age, lifestyle and diet can all play a part, it could be a decline in testosterone that's causing the issues you're experiencing, and it may be time to consider getting your hormone levels checked.

The Decline in Testosterone Levels as We Age

Since testosterone levels begin to decline in the mid-thirties, by the time you reach 70 years of age, there could be a decline of as much as 30%. (6) Of course, various factors can affect testosterone levels, but when they drop to below-normal levels, they can affect all areas of physical and mental health. According to a study (7), testosterone levels are more closely related to behavioral and health-related issues than aging. 

When levels dip below 200 ng/dL, even if you feel okay, other health-related symptoms could appear that can jeopardize health (8), such as reduced bone density and cognitive decline. 

How Low Testosterone Affects Health

There is much controversy around having an official low testosterone level and how it affects your health. Firstly, because everyone is different; secondly, it does not consider the patient's symptoms and how they feel. 

According to the American Urological Association, (9) low testosterone is considered under 300 ng/dL and may produce some symptoms that include: 

  • Loss of muscle mass
  • Trouble concentrating
  • Weight gain
  • Low energy
  • Trouble sleeping
  • Low sex drive
  • Erectile dysfunction
  • Bone loss
  • Irritability
  • Depression
  • Hair loss

But, it is essential to remember that many men experience these symptoms at 400 ng/dL, 600 ng/dL or even 900ng/dL. It is all dependent on receptor sensitivity, free testosterone levels, thyroid hormone levels, and a host of other factors.

What is the Best Time of Day to Take a Testosterone Test?

According to Ronald Swerdloff, MD, chief of endocrinology at Harbor UCLA Medical Center, to get the most accurate hormone reading, the blood test should be done in the morning when the average person would have the highest level. 

Since hormones can have patterns of secretion, afternoon testing can provide false information about low levels. To be sure reading is accurate, it's also a good idea to test more than once. Two to three times over several weeks or months can ensure accurate readings.

Are Levels Actually That Important?

Unfortunately, most medical professionals haven't had the necessary training to understand hormones and what it means to have optimal levels. While they may be aware of the need for hormone replacement, they focus on baseline test numbers that don't even come close to telling the whole story.

According to medical research, it's well documented that the 'normal levels' the medical community has been trained to use don't provide optimal levels for most men. Despite this, they continue to focus on the numbers and the symptoms the patient is experiencing are ignored.

The symptoms of low testosterone can severely interfere with your quality of life in all areas. When you don't feel your best, it takes a toll on your enjoyment of life and relationships with the people you care about. What you may not understand is that it also significantly affects your health. 

Although your medical practitioner may focus on the hormone levels test, only you know how you feel. You don't have to live with the negative symptoms of low testosterone. If your practitioner doesn't give you the support you need, it may be time to consult a specialist who can. 

What is a Testosterone Level Test?

According to the Cleveland Clinic (10), A testosterone test is a blood test that measures the level of the predominantly male hormone testosterone. Since the body functions at its best in an optimal range, levels, either too low or too high, can cause various health problems. 

Testosterone exists in the body as bound testosterone, which is bound to sex hormone binding globulin (SHBG) or free testosterone, which isn't attached to anything. The body can utilize free testosterone more easily than bound testosterone. In a testosterone blood test, results may show: (11). 

  • Total testosterone test. Measures both free testosterone and bound testosterone. The test should be done between 8 a.m. and 10 a.m. for best results. 
  • Estradiol. This form of estrogen is vital for a healthy sex drive, erections and sexual function. Estradiol also offers protection to brain health and bones. If estradiol is out of balance, it reduces the effectiveness of TRT. 
  • DHEAs. DHEA sulfate is an adrenal hormone that kick-starts the production of other hormones like testosterone. DHEA supplements are often recommended as part of our programs. 
  • Free T3. T3 is an active thyroid hormone that controls metabolism, promotes fat burning, and, if deficient, can be one of the biggest threats to overall hormone health. If your clinic doesn't offer this test, move swiftly on.  
  • PSA. A Prostate-specific androgen test checks levels of PSA, which, if too high, may indicate a prostate issue. We always check PSA is within the normal range before starting any TRT. 

Why Would You Need a Testosterone Level Test?

If you've struggled with symptoms of low testosterone or have health issues that could be related, your provider may suggest you have testosterone levels checked. They can include:

  • Erectile dysfunction (ED)
  • Weight gain around your middle
  • Low energy levels
  • Brain fog
  • Developing breast tissue
  • Loss of muscle mass
  • Low sex drive
  • Type 2 diabetes

So, what can you do if your testosterone levels are out of whack? You may want to consider testosterone replacement therapy to feel like yourself again and enjoy the benefits of optimal testosterone levels. 

What is Testosterone Replacement Therapy

Testosterone replacement therapy (TRT) is a medical treatment that utilizes medications in various forms, including injections, creams, patches, gels or pellets, to increase testosterone levels in the body. By replacing lost testosterone, you'll experience renewed energy and vigor and enjoy a better quality of life.


Testosterone is a vital hormone that allows men to perform at their best. Changes occur in testosterone levels by age, with a decline starting in the mid-thirties with symptoms that can include a low sex drive, loss of energy and reduced strength and muscle mass that affect men physically and psychologically. 

The key takeaway is not to fixate on numbers. In all reality, if your hormone specialist knows their stuff, you shouldn't even need a blood test. Your symptoms are like a mirror of your hormone health. We do blood tests, one, so we have a baseline to work from, and two, because people like to know their levels, but remember your symptoms are the true reflection of your hormones, and the numbers are pretty meaningless.

So, if you have symptoms of low testosterone, help is available. Testosterone replacement therapy can reduce the unwanted effects of low testosterone and give you your life back. 

Find out If TRT is for you by completing your free online health assessment.

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