What’s a Normal Testosterone?

April 8th, 2013 § 6 comments § permalink

Wiki (not sure if that’s his real name) wrote in a comment, “is low Testosterone unusual for young athletic men (under 25) , what will be your minimum level (red line) for Testosterone of men under 25, as i found the minimum level varies according to each lab … mostly skewed based on the middle aged men they usually test.”

Great question! A while ago, many used “age-indexed” testosterone, meaning that lower levels were considered normal in older men. Most in the field have abandoned that approach as it’s like saying, we know that diabetes is more common as people age, so we’ll just use higher blood sugars as normal when they get older. That would be an approach ignorant of the basis of the disease. To make matters worse, to create the age-indexed thresholds of normal testosterone, each lab essentially was required to do that themselves. So you had a lot of labs with different numbers, and that made interpreting those lab results really difficult.

Your question gets to another point, though, which is what is a normal testosterone for an individual man? Testosterone doesn’t work by itself; a whole machine inside the cell uses it. It’s like gas in a car: you can have the same gas, but a Ferrari will drive differently than a Volvo. (No offense to Volvo owners intended.) So one man’s testosterone of 350 ng/dL may be perfectly fine, but for another, that may be low.

That’s why guys need to do evaluation and treatment with their doctors. (If you are trying to figure out a good doctor who knows about hormones in men, check out that part of the FAQ.) A doctor can evaluate the whole man and see other signs of low testosterone, and tailor treatment with different medications (many of which are described elsewhere in this blog.)

Thanks, Wiki, for the great question!