Testosterone Levels in Men and Women
Maintaining healthy testosterone levels is one of the most important things you can do as you age. Your body will naturally begin to decrease the amount of testosterone it produces before you reach age thirty. While the yearly decrease is slight, it will add up over time, sometimes leading to symptoms of testosterone deficiency. Also called hypogonadism or Low T (for low testosterone), this condition can start as mildly annoying but turn into something more debilitating if left untreated.
Healthy testosterone levels in men and women help to maintain the following functions:
- Libido and sex drive
- Sexual performance
- Heart health – balancing cholesterol, triglyceride, and blood pressure levels
- Red blood cell production
- Cognitive functions and memory
- Hair growth
- Metabolism and weight control
- Insulin and glucose levels
- Bone density and muscle growth
- Sleep cycles and energy levels
As you can see, when testosterone levels decrease with age, they can lead to many unwanted changes in the body. Adults with severe Low T may experience feelings of depression, mood changes, social isolation, and decreased quality of life.
Testosterone is just as crucial for women as it is for men. A female needs testosterone to maintain her red blood cell count, bone density, muscle tone, and brain functions. Testosterone helps ensure proper vaginal lubrication and sex drive at any age. Since the body converts some of the extra free testosterone into estradiol, it is essential to maintain healthy testosterone levels to support estrogen production. Both men and women need estrogen to help support strong bones.
Maintaining healthy testosterone levels at any age is essential for men and women.
What Is the Difference Between Total, Free, and Bioavailable Testosterone Levels?
Testosterone exists in the bloodstream in different forms. The majority of the testosterone that enters the blood binds itself to one of two proteins:
- Sex hormone-binding globulin (SHBG)
- Albumin
The binding of testosterone to a protein is necessary for transport through the bloodstream because testosterone is not water-soluble. It is a fat-soluble protein that cannot move through the blood on its own. The binding to SHBG is tight, inhibiting that testosterone from entering any androgen receptor cells without it breaking free from the SHBG. Estradiol and dihydrotestosterone (DHT) also bind to SHBG in the bloodstream as they are also steroid, fat-soluble hormones.
As we begin our close look at the three testosterone levels definition, we start with total testosterone. Total testosterone encompasses all testosterone in the bloodstream – that which is bound to albumin and SHBG, as well as any free testosterone. Free testosterone is that which is not bound to a protein and makes up about 2 percent of all testosterone. It is readily available to enter any androgen receptors it is near as it cannot move freely through the bloodstream.
The binding of testosterone to albumin is weak, allowing it to dissociate freely in the capillary bed so that it is available for tissue uptake by the androgen receptors. Bioavailable testosterone encompasses both the albumin-bound testosterone along with any free testosterone.
When we look at testosterone levels over time, we sometimes find that DHT and estradiol levels rise while testosterone levels fall. That is because, with age, the body increases the conversion of testosterone into these two hormones.
There are three types of testosterone levels: total, free, and bioavailable.
What Are Normal, High, and Low Testosterone Levels in Men?
When it comes to diagnosing low testosterone levels, men have long found themselves in a bit of a dilemma – no two labs used the same reference values. Even to this day, the information online can seem confusing. However, the American Urological Association has now stated that the acceptable cut-off total testosterone level of 300 ng/dL is the best number to use for maximizing benefits from prescribing testosterone therapy. However, they have also left it open to doctors to look at symptoms of Low T when diagnosing testosterone deficiency. Some men may have slightly higher total testosterone levels yet still have symptoms, necessitating the prescribing of testosterone replacement therapy (TRT).
The current total testosterone levels male range as assessed by LabCorp is 246 to 916 ng/dL. Other reports list it as between 270 and 1070 ng/dL. The healthiest level for middle-aged and older men is between 450 and 600 ng/dL, and that is what we strive for when prescribing TRT for men.
In many instances, only total testosterone levels require testing, along with many other hormones and blood panels. However, there are times when total testosterone levels may seem in range, and free testosterone levels are necessary to test. A deficiency in free testosterone can mean one of three things:
- The testosterone bound to SHBG cannot break free to enter the androgen receptors
- The enzyme aromatase is converting the free testosterone to estradiol too quickly before it can bind with the androgen receptors – elevated estrogen levels will be present
- 5-alpha reductase, the enzyme responsible for DHT conversion of testosterone is reducing free testosterone and boosting DHT levels
The following chart shows the normal range for free testosterone levels for men by age per the Mayo Clinic Labs:
| Male Age | Normal Range of Free Testosterone Levels |
| 25 – 30 | 5.05 – 19.8 ng/dL |
| 30 – 35 | 4.85 – 19.0 ng/dL |
| 35 – 40 | 4.65 – 18.1 ng/dL |
| 40 – 45 | 4.46 – 17.1 ng/dL |
| 45 – 50 | 4.26 – 15.4 ng/dL |
| 50 – 55 | 4.06 – 15.6 ng/dL |
| 55 – 60 | 3.87 – 14.7 ng/dL |
| 60 – 65 | 3.67 – 13.9 ng/dL |
| 65 – 70 | 3.47 – 13.0 ng/dL |
| 70 – 75 | 3.28 – 12.2 ng/dL |
| 75 – 80 | 3.08 – 11.3 ng/dL |
The testing of bioavailable testosterone levels in men is not often used, but if so, here is the established reference range by Mayo Clinic Labs by age:
- 30 to 39 years: 72 to 235 ng/dL
- 40 to 49 years: 61 to 213 ng/dL
- 50 to 59 years: 50 to 190 ng/dL
- 60 to 69 years: 40 to 168 ng/dL
No reference range is established for men over 70 years for bioavailable testosterone levels.
The most commonly tested level for men is total testosterone.
What Are Testosterone Levels in Women?
Assessing normal testosterone levels for women is a bit different. Whether a woman is pre or post-menopausal can make a difference in her total testosterone levels, as shown below:
- Total premenopausal testosterone levels: 10.0 to 55.0 ng/dL
- Total postmenopausal testosterone levels: 7.0 to 40.0 ng/dL
Although there are also variances in free testosterone levels by age, female changes are very slight. Between the ages of 25 and 30, a woman’s natural free testosterone is between 0.06 and 1.06 ng/dL. The upper range drops to 1.03 for the next five years, and then to 0.98 ng/dL between ages 40 and 45. The decrease continues at a rate of .02 to .03 ng/dL every five years. By the time a woman reaches age 60, her free testosterone is between 0.06 and 0.87 ng/dL. The decline continues at the same pace throughout the rest of her life.
Bioavailable testosterone levels in women will differ based on whether or not oral estrogen therapy is in use:
- Women 20 to 50 years of age on oral estrogen: 0.8 to 4.0 ng/dL
- Women 20 to 50 years of age not on oral estrogen: 0.8 to 10 ng/dL
Women have naturally lower testosterone levels than men, but it is just as crucial to maintain a healthy supply of testosterone in the female body.
How to Check Testosterone Levels?
When it comes to checking testosterone levels, age means everything. The older a person gets, the more likely the risk of developing low testosterone. Doctors measure testosterone and other hormones first thing in the morning when their levels are at their highest. Because food can interfere with testosterone readings, the testosterone levels test is done while fasting.
Even if the results are in the normal range in the testosterone levels age chart, a person may still be testosterone deficient. Because the range of normal testosterone levels is extensive, people who are at the lower end of the normal range may also suffer from symptoms of low testosterone. A hormone specialist knows that it takes both symptoms as well as lower levels of testosterone to diagnose Low T in men and women.
Blood testing performed first thing in the morning while fasting provides the most accurate assessment of testosterone levels.
What to Do If Your Testosterone Levels Are Not Normal
Although it is unlikely that older adults will have normal testosterone levels based on blood test results, that does not necessarily mean they have Low T. Testosterone deficiency requires symptoms of Low T as well as corresponding blood test results. Many people have low levels of testosterone without any of the signs of Low T. If that is the case, then there is no need for treatment.
Only when symptoms are present is testosterone therapy warranted. Contacting a doctor who specializes in hormone replacement therapy for diagnostic testing and treatment is the best option. The goal of raising testosterone levels by age in men is to return them to the point they were at when a man was in his twenties – aiming for between 500 and 650 ng/dL for the best possible results.
For further information on testosterone levels, how to check where they are at now, treatment options, and how to proceed, please contact RX Hormone medical clinic for a complimentary, confidential telephone consultation.