F.I.S.T.
07-14-2013, 09:13 PM
What’s a “Normal” Testosterone Level and How to Measure Your T
Today we’ll be taking a look at what’s considered a normal testosterone level and how you can get your testosterone levels tested. As I began researching testosterone levels and hormone testing for this series, I quickly learned that there’s a lot of conflicting and confusing information out there — some websites will say that “X” is a normal testosterone level, while another website says “Y” is the ideal range. Even medical labs give conflicting numbers on what’s a normal testosterone level.
Why so much confusion?
The problem is that there hasn’t been much standardization in hormone testing, particularly regarding T levels. Different labs use different methods (and measurements), which has only created confusion among consumers and even family doctors about what testosterone level results even mean.
Hopefully, the current state of confusion will soon change. The Center for Disease Control here in the U.S. started a project in 2010 to get labs to agree on standard hormone testing procedures (http://www.cdc.gov/labstandards/hs.html). It’s slowly gaining ground, but not every lab has signed on.
I also learned that the bottom range of what’s considered “normal” by many doctors is actually woefully underestimated. Doctors are telling men who come to them with symptoms of low testosterone, “Well, you’re barely within normal range, but it’s still normal, so… you’re fine!”
No, Dr. Everything’s-A-Okay. It’s not fine.
I hope in this post I can clarify some of the confusion surrounding testosterone levels and hormone tests. I’ll be straight with you. This stuff is super confusing. I’ve done my best to synthesize all the disparate info out there into an easy-to-read format for the layman and have sought to create the most accessible resource on the web. But, I’m not a scientist or doctor, and may have gotten a few things wrong. If any of you professional endocrinologists see an error, I welcome your corrections.
Total and Free Testosterone Levels
Before we begin, I want to reiterate the fact that there are three different types of testosterone floating in your body: free testosterone, SHBG-bound testosterone, and albumin-bound testosterone. When you get tested, there are two tests you can get: total testosterone and free testosterone.
Total testosterone is the total amount of T floating in your blood at the time of the test: free, SHBG-bound, and albumin-bound combined. Total testosterone is typically measured in ng/dl, or nanograms per decilitre.
Free testosterone is the measurement of — you got it — free testosterone (which often includes albumin-bound testosterone as well because it can easily convert to free T). Free T is typically measured in picograms per milliliter. As we’ll discuss later in this post, because free testosterone makes up such a tiny, tiny percentage of your total T, it’s really hard to measure accurately. So, when you see research on normal testosterone levels, it usually focuses on total testosterone. Consequently, most of the numbers in this post will be about total T levels. With that said, I do include some references to research that indicates what average and optimal free testosterone levels are.
What’s a “Normal” Testosterone Level?
When you go to get tested for testosterone, the lab will often show you what’s considered the “normal” range among patients who have tested with that particular lab. It’s called the “reference range.”
(http://en.wikipedia.org/wiki/Reference_range)
For example, LabCorp (the lab I used to test my T levels here in Tulsa, OK) shows a reference range of 348 – 1197 ng/dl (nanograms per decilitre) for total testosterone levels. According to this reference range, my total testosterone level of 383 ng/dl at the beginning of my experiment would mean my total T levels were — barely — within the normal range.
Here’s the problem.
That reference range consists of a wide variety of men who tested with LabCorp: 80-year-old men and 20-year-old men; obese men and super fit men; men with pituitary gland problems and men with glands that work like champs.
Sure, my 383 ng/dl was considered normal, but normal compared to whom? An 80-year-old man with Type 2 diabetes?
The fact that reference ranges don’t break patients down by age or health status explains why a 30-year-old man can go to his doctor with the symptoms of low T, only to be told that his T levels are fine because they’re within the “normal” range. If you’re 30 (or even 50), but have the same testosterone level as an 8o-year-old, diabetic man, your doc may say you’re okay, but you’re still not going to feel good. Plain and simple.
What’s interesting is that for many years, the bottom number of the reference range for T levels at many medical labs was much lower. For example, up until last year, LabCorp’s reference range for testosterone was 249-836 ng/dl. You could have had a testosterone level of 250 (which is super low) and still be told by your doctor that you were normal.
All this is to say that the “normal” levels put out there by doctors and labs aren’t all that useful.
Average Testosterone Levels by Age
When determining what’s considered a normal testosterone level, it’s best to look at what the reference range is for men your age. Researchers have known for years that T levels typically drop by about 1% every year after you hit your mid-30s. So if you’re 35, comparing yourself to a bunch of 80-year-old men isn’t very useful because they likely have really low T levels.
Today we’ll be taking a look at what’s considered a normal testosterone level and how you can get your testosterone levels tested. As I began researching testosterone levels and hormone testing for this series, I quickly learned that there’s a lot of conflicting and confusing information out there — some websites will say that “X” is a normal testosterone level, while another website says “Y” is the ideal range. Even medical labs give conflicting numbers on what’s a normal testosterone level.
Why so much confusion?
The problem is that there hasn’t been much standardization in hormone testing, particularly regarding T levels. Different labs use different methods (and measurements), which has only created confusion among consumers and even family doctors about what testosterone level results even mean.
Hopefully, the current state of confusion will soon change. The Center for Disease Control here in the U.S. started a project in 2010 to get labs to agree on standard hormone testing procedures (http://www.cdc.gov/labstandards/hs.html). It’s slowly gaining ground, but not every lab has signed on.
I also learned that the bottom range of what’s considered “normal” by many doctors is actually woefully underestimated. Doctors are telling men who come to them with symptoms of low testosterone, “Well, you’re barely within normal range, but it’s still normal, so… you’re fine!”
No, Dr. Everything’s-A-Okay. It’s not fine.
I hope in this post I can clarify some of the confusion surrounding testosterone levels and hormone tests. I’ll be straight with you. This stuff is super confusing. I’ve done my best to synthesize all the disparate info out there into an easy-to-read format for the layman and have sought to create the most accessible resource on the web. But, I’m not a scientist or doctor, and may have gotten a few things wrong. If any of you professional endocrinologists see an error, I welcome your corrections.
Total and Free Testosterone Levels
Before we begin, I want to reiterate the fact that there are three different types of testosterone floating in your body: free testosterone, SHBG-bound testosterone, and albumin-bound testosterone. When you get tested, there are two tests you can get: total testosterone and free testosterone.
Total testosterone is the total amount of T floating in your blood at the time of the test: free, SHBG-bound, and albumin-bound combined. Total testosterone is typically measured in ng/dl, or nanograms per decilitre.
Free testosterone is the measurement of — you got it — free testosterone (which often includes albumin-bound testosterone as well because it can easily convert to free T). Free T is typically measured in picograms per milliliter. As we’ll discuss later in this post, because free testosterone makes up such a tiny, tiny percentage of your total T, it’s really hard to measure accurately. So, when you see research on normal testosterone levels, it usually focuses on total testosterone. Consequently, most of the numbers in this post will be about total T levels. With that said, I do include some references to research that indicates what average and optimal free testosterone levels are.
What’s a “Normal” Testosterone Level?
When you go to get tested for testosterone, the lab will often show you what’s considered the “normal” range among patients who have tested with that particular lab. It’s called the “reference range.”
(http://en.wikipedia.org/wiki/Reference_range)
For example, LabCorp (the lab I used to test my T levels here in Tulsa, OK) shows a reference range of 348 – 1197 ng/dl (nanograms per decilitre) for total testosterone levels. According to this reference range, my total testosterone level of 383 ng/dl at the beginning of my experiment would mean my total T levels were — barely — within the normal range.
Here’s the problem.
That reference range consists of a wide variety of men who tested with LabCorp: 80-year-old men and 20-year-old men; obese men and super fit men; men with pituitary gland problems and men with glands that work like champs.
Sure, my 383 ng/dl was considered normal, but normal compared to whom? An 80-year-old man with Type 2 diabetes?
The fact that reference ranges don’t break patients down by age or health status explains why a 30-year-old man can go to his doctor with the symptoms of low T, only to be told that his T levels are fine because they’re within the “normal” range. If you’re 30 (or even 50), but have the same testosterone level as an 8o-year-old, diabetic man, your doc may say you’re okay, but you’re still not going to feel good. Plain and simple.
What’s interesting is that for many years, the bottom number of the reference range for T levels at many medical labs was much lower. For example, up until last year, LabCorp’s reference range for testosterone was 249-836 ng/dl. You could have had a testosterone level of 250 (which is super low) and still be told by your doctor that you were normal.
All this is to say that the “normal” levels put out there by doctors and labs aren’t all that useful.
Average Testosterone Levels by Age
When determining what’s considered a normal testosterone level, it’s best to look at what the reference range is for men your age. Researchers have known for years that T levels typically drop by about 1% every year after you hit your mid-30s. So if you’re 35, comparing yourself to a bunch of 80-year-old men isn’t very useful because they likely have really low T levels.