Testosterone levels: What’s normal?

As a society, we tend to place a lot of significance on certain words.

The word “normal” is one of them.

With that in mind, one of the most often asked questions in the field of men’s health is “what are normal testosterone levels in men?”

Both the media and health professionals are capitalizing on this question by talking about “low T” and urging men to turn to hormone replacement therapy to boost their testosterone levels.

But before men should even consider taking steps to raise their testosterone levels (which can be done in a number of natural ways), we return to the basic question: what are normal testosterone levels in men? Here is the not-so-simple answer.

What are the forms of testosterone?

First of all, there is more than one form of testosterone:

• One is bonded with sex hormone binding globulin (SHBG), which is the most common type and makes up about 65 percent of total testosterone. The testosterone attached to SHBG typically cannot be separated from the hormone, so this T is not considered to be bioavailable. Testosterone that is bioavailable is the form that is used by the body.
• One is bonded to the protein albumin, making up about 35 percent of your total testosterone. This testosterone is considered to be potentially bioavailable because it can be “coaxed” away from the protein.
• One is free, which means it is not attached to any protein. Free testosterone makes up about 2 percent of total T and is the form that is completely bioavailable to be used by the body. Free testosterone travels throughout the bloodstream and can bind to receptors in the muscles, brain, and other organs.

Getting your testosterone levels checked

After you undergo the simple blood test that measures your testosterone levels, your doctor will give you the results represented by three different numbers:

• Total testosterone. This represents the total amount of testosterone that is circulating throughout your body, so it includes both types of bonded T plus free T
• Bioavailable T, which consists of testosterone attached to albumin plus free T
• Free T

Now comes the complicated part. The definition of “normal” testosterone varies, depending on the expert and the testing lab used. The good news is that there are general guidelines for “normal” testosterone. Here are the generally accepted normal ranges of total, free, and bioavailable T, given in nanograms of testosterone per deciliter (ng/dL) for different age groups:

Total T:

• 240 to 950 ng/dL for men age 19 years and older

Free T:

• 5.05 to 19.8 ng/dL for men 25 to 29
• 4.86 to 19.0 ng/dL for ages 30 to 34
• 4.65 to 18.1 ng/dL for ages 35 to 39
• 4.46 to 17.1 ng/dL for ages 40 to 44
• 4.28 to 16.4 ng/dL for ages 45 to 49
• 4.06 to 15.6 ng/dL for ages 50 to 54
• 3.87 to 14.7 ng/dL for ages 55 to 59
• 3.67 to 13.0 ng/dL for ages 60 to 64
• 3.47 to 13.0 ng/dL for ages 65 to 69
• 3.28 to 12.2 ng/dL for ages 70 to 74

Bioavailable T:

• 83 to 257 ng/dL for men 20 to 29
• 72 to 235 ng/dL for men 30 to 39
• 61 to 213 ng/dL for men 40 to 49
• 50 to 190 ng/dL for men 50 to 59
• 40 to 168 ng/dL for men 60 to 69

No ranges have been determined for men age 70 and older. Clinically low total testosterone levels are recognized as less than 220 to 300 ng/dL.

Bottom line on normal testosterone levels in men

Here is the bottom line when it comes to answering the question, what are normal testosterone levels in men.

• The range of “normal” is wide, which accommodates the fact that every man’s needs are different.
• While a man’s total testosterone level can be within the normal range, free T levels can be low, which can result in symptoms of low T.
• The testosterone level men should be most interested is in the bioavailable number. If men can boost their bioavailable testosterone level, they should expect an increase in energy, sex drive, and muscle strength as well as better mood and well-being.