Why are my labs "normal"?

142 laboratories measured the same blood and disagreed wildly at female concentrations.

You asked for the test. That already puts you ahead of most women, because usually nobody offers it. The result came back, someone told you it was normal, and that was the end of the conversation.

I want to explain what that number actually is, because "normal" is doing a lot of work in that sentence, and most of it isn't the work you think.

What happened to me

I've been on an antidepressant for thirty years. It works, in the sense that it does the job serotonin drugs do. What it never touched was the flatness.

I didn't want to get out of bed in the morning. Not sadness, and not exhaustion either. I couldn't feel any pull toward the things I used to care about. I'd look at work I'd chosen, that I'd built myself, and feel nothing reaching back. Thirty years of treated depression and that part never moved, because SSRIs work on serotonin and what I'm describing runs on dopamine. Those are different systems. You can be genuinely well treated for depression and still have this.

Nobody ever suggested my hormones. I'm a medical technologist. I've drawn blood for years and I can read my own results, and it still didn't occur to anyone to look, including for a long time me.

Here's the part that changed how I think about lab reports. It wasn't even testosterone that taught me, it was estrogen. I was on hormone therapy, and my estradiol was too low, and nobody ever told me. Not once. I only found out because I'm a medical technologist and I know what estradiol looks like in a twenty-year-old, so when I read my own number I could see it was nowhere near that. My doctor was looking at the same result and calling it fine.

That's the whole problem, and I got lucky in a way most women don't. I had the background to see it. If you don't, you get the word "normal" and no reason to push.

On testosterone, the flatness lifted by about ninety percent. I want to be exact about that, because "it fixed me" would be a lie and this subject has enough of those. Roughly ten percent is still there and I still notice it. But I wake up wanting the day now. I finish things because I want to, not because I've talked myself into it. I hate, hate, hate anhedonia, and I got most of the way out of it, and no lab number was ever going to be the thing that told me so.

The number is less solid than it looks

In 2017, researchers at the CDC and the New York State Department of Health ran a proficiency test. They took unaltered blood serum from four donors, two men and two women, split each sample, and sent it to 142 certified clinical laboratories. Those labs used 16 different testosterone assays. Everyone was measuring the exact same blood.

Then the researchers compared every lab's answer against a reference method, the closest thing there is to a true value.

Here's what came back. For the sample with the lowest testosterone concentration, 15.5 ng/dL, which is squarely in the female range, the labs' results ranged from 17.8% below the true value to 73.1% above it. Same blood. Same day. Different labs.

For the two samples in the male range, 402 and 498 ng/dL, the spread was much tighter, roughly 25% below to 9% above.

Read those two paragraphs again, because that gap is the whole story. The assays do a reasonable job at male concentrations. At the concentrations found in women's blood, they scatter.

(Cao, Botelho, Rej and Vesper, Clinica Chimica Acta, 2017. 142 laboratories, 16 assays, four single-donor specimens, reference-method target values.)

This isn't a fringe complaint

I want to be careful here, because "the tests are wrong" is exactly the kind of thing that shows up on supplement websites, and I don't want to be mistaken for one.

So: in 2019, eleven professional bodies published a joint position statement on testosterone therapy for women. The list includes the Endocrine Society, the American College of Obstetricians and Gynecologists, the North American Menopause Society, and the Royal College of Obstetricians and Gynaecologists. This is the establishment, not the fringe.

Their statement grades each recommendation by evidence strength. On measurement, they wrote that direct assays for total and free testosterone are highly unreliable in the female range, and they graded that finding A, their highest level of evidence.

The same document says total testosterone can be measured accurately using chromatography with tandem mass spectrometry, which is graded B.

So the professional consensus and the proficiency data agree. The common test is not reliable at your concentrations, and a better method exists.

(Davis et al., Journal of Clinical Endocrinology and Metabolism, 2019. Global Consensus Position Statement, endorsed by eleven societies.)

What to ask for

If a testosterone level is going to be measured at all, ask whether the lab is running LC-MS/MS, liquid chromatography with tandem mass spectrometry. That is the method the consensus statement grades as accurate.

The alternative, usually called a direct or immunoassay method, is the one that produced the scatter above. It is cheaper and it is what most labs run by default.

This is a reasonable question to ask, and any lab can tell you which method they use.

The part that complicates the popular version

Here is where I have to disagree with a lot of what's written about this, including things I've seen repeated confidently.

The usual advice is that total testosterone is meaningless and free testosterone is what matters, because free testosterone is the fraction not bound to sex-hormone-binding globulin and therefore the biologically active part.

The 2019 consensus statement does not endorse that. It says research should focus on total testosterone as the main biomarker, specifically because the evidence that free testosterone is the biologically active fraction is weaker than people assume. It also notes that direct assays for free testosterone are unreliable in the female range, which is the same problem again.

I'm flagging this because I'd rather tell you the evidence is unsettled than hand you a clean story that isn't true. Free testosterone measured properly, by equilibrium dialysis, is a real measurement. But "get your free T checked" is not the settled answer it's often presented as, and a free testosterone number from a direct assay carries the same reliability problem as the total.

The androgens nobody put on your panel

There's a second issue, and it isn't about accuracy. It's about what gets measured at all.

Your adrenal glands make a family of androgens called 11-oxygenated androgens. The best studied is 11-ketotestosterone. They are not on a standard hormone panel, so if you've had testosterone tested, you almost certainly have no idea what yours are.

In a 2020 study measuring hormones by mass spectrometry in 590 adults aged 18 to 97, 11-ketotestosterone stayed statistically flat across adult life in women, while classic testosterone declined with age.

That matters because it means the hormone most panels measure is falling while another meaningful androgen pool isn't, and only one of them is being looked at.

Where do they come from? A 2022 study sampled blood directly from the adrenal and ovarian veins and found these androgens come from the adrenal glands rather than the ovaries. That study looked at only four patients, all of them cases of hyperandrogenism rather than typical women, so treat it as suggestive rather than settled. I'm telling you the sample size because a four-person study and a 590-person study are not the same kind of evidence, and papers that don't tell you which one they're citing are hiding something.

The practical implication, if it holds: menopause doesn't touch this pool, and your standard panel never showed it to you.

(Davio et al., Journal of Clinical Endocrinology and Metabolism, 2020, n=590. Auer et al., European Journal of Endocrinology, 2022, n=4.)

So what does "normal" mean

Putting it together, when you were told your testosterone was normal, that sentence rested on:

a measurement method the consensus grades as highly unreliable at your concentrations, unless the lab happened to run mass spectrometry
a reference range built from a population, which tells you where you sit relative to other women, not whether the level is right for you
one androgen, measured once, while a second adrenal androgen pool went unmeasured

None of that means your level is actually low. It might genuinely be fine. What it means is that "normal" was a weaker statement than it sounded, and you were not given enough to know either way.

What I'd actually do with this

Not medical advice, and I'll say why at the end. But practically:

Find out which assay your result came from. If it was a direct immunoassay, you know how much confidence to place in the specific number.
If testing again, ask for LC-MS/MS.
Test in the morning, since testosterone follows a daily rhythm, and be consistent about timing between tests.
Ask for SHBG alongside it. It changes how much testosterone is available, and oral estrogen raises it substantially while transdermal estrogen does not.
Hold the number loosely. The consensus statement is explicit that a blood testosterone level should not be used to diagnose the one condition testosterone therapy is actually evidence-based for.

That last point surprises people, so I'll repeat it. The eleven societies say the diagnosis comes from clinical assessment, not from the lab value. If a number sent you away, the number was being asked to do something the evidence says it can't do.

A word about what I am and am not. I'm a medical technologist. I've spent a long time reading primary research and I run labs for a living, which is exactly why the proficiency data above bothers me. I'm not a physician, I'm not diagnosing you, and nothing here is a treatment recommendation. Take it to a clinician who knows your history, and ask them the assay question directly.

If this was useful, the six-part email series goes through the rest of it: what testosterone actually does, why the trials missed it, the side effects nobody quantifies honestly, and how women are getting prescriptions.