Get your testosterone tested before 10 a.m. and do it twice

Book the 7:40 a.m. draw. Not the 2 p.m. one that fits between the school run and your standing Tuesday call. Testosterone follows a daily rhythm, it peaks in the early morning, and by mid-afternoon the same man can post a number low enough to start a conversation he didn't need to have. The American Urological Association's guideline is built around morning measurement for exactly this reason, and it uses 300 ng/dL as the line for a low testosterone diagnosis. A 2 p.m. draw can walk a normal man across that line and a lot of guys have spent real money finding that out the hard way.

So the first thing you do isn't buy a supplement or a subscription. It's pick a better appointment slot.

The morning rule, and the part nobody tells you

Before 10 a.m. is the standard. Earlier is better. Fasted is preferred, because eating can nudge the number down, and it also makes life simpler if you're getting lipids and glucose at the same visit, which you probably should be if you're over 35 and haven't in a while.

The diurnal swing is sharpest in younger men and flattens out with age, which is why you'll occasionally hear that timing doesn't matter much at 60. Maybe. But you're not testing to win an argument about physiology, you're testing to get a number your doctor can act on, and every guideline he's working from assumes a morning sample. Give him the sample the guideline describes.

Now the part the lab requisition doesn't mention. Don't test during a bad week. Testosterone drops with acute illness, with real sleep deprivation, with a crushing training block you haven't recovered from, with heavy drinking, with the flu you're 60 percent over. If you got four hours of sleep because the two-year-old had an ear infection, reschedule. It costs you nothing. A misleading low costs you months.

Pick a week that looks like your actual life. Normal work, normal sleep, normal training. Not deload week, not the week after the Spartan race.

Ask what assay they're running

This is where most men stop paying attention, and it's the difference between a number you can trust and a number you can't.

Total testosterone is the headline result. It can be measured two ways. Immunoassay is fast, cheap and standard at most commercial labs. Liquid chromatography with tandem mass spectrometry, written LC-MS/MS, is the reference method, and it's the one the Endocrine Society points toward for accuracy, especially at low concentrations and in men on the borderline. If your result is going to decide something, ask whether the lab can run LC-MS/MS.

Then there's free testosterone, and here's where the money gets wasted. Most of your testosterone is bound to sex hormone binding globulin and albumin. Free testosterone is the unbound fraction. The problem is that the cheap direct free testosterone immunoassay is widely regarded as unreliable. The defensible options are equilibrium dialysis, which is the gold standard and not available everywhere, or a calculated free testosterone using your total testosterone, your SHBG and your albumin.

Which means: if free T is going to be part of the picture, order SHBG and albumin in the same draw. SHBG rises with age and falls with obesity and insulin resistance, so two men with identical total testosterone can be in genuinely different situations. Skipping SHBG is the single most common gap in a panel I see men bring to a doctor.

One more. If you take a high-dose biotin supplement, stop it several days before the draw and tell the lab. The FDA has warned that biotin interferes with a range of immunoassays, hormone tests included. Half the hair-and-nails gummies in the house have absurd biotin doses in them.

What else goes on the slip

Testosterone by itself tells you a level, not a cause. A doctor working the problem properly will usually want LH and FSH, because they separate a testicular problem from a pituitary or hypothalamic one, and that changes everything about what happens next. Prolactin comes in when LH is low and testosterone is very low. Iron studies matter, because hereditary hemochromatosis is an underappreciated cause of low testosterone and it's a diagnosis you'd rather have early. A CBC gives a baseline hematocrit. An A1c is reasonable because metabolic health and testosterone travel together.

Don't order all of this yourself off a website. Bring the list to your physician and let him decide which ones apply to you. That's the point of having one.

The second sample isn't optional

One low result is a data point. Two low morning results on separate days are a finding.

Testosterone is biologically variable enough that a single number near the threshold means very little. The guidelines call for two separate early-morning measurements before anyone says the word hypogonadism, and the guys who skip this step are overwhelmingly the ones who end up on a treatment they didn't need.

Do the second draw at the same hour, ideally the same lab, same assay, at least a few days later. Reference ranges vary between labs, so a 310 at one shop and a 290 at another can be the same underlying reality wearing different clothes. Keep the variables boring.

And understand what the number can't do. A result inside the reference range doesn't automatically explain away fatigue, and a result under 300 with no symptoms at all isn't a mandate to treat. The diagnosis is the lab plus the symptom picture, together. Your doctor will ask you some personal questions in that conversation. Answer them straight. He's heard it.

Before you conclude it's your hormones

Untreated sleep apnea suppresses testosterone, and it's rampant in men who snore, carry extra weight around the middle, and wake up unrefreshed. Significant weight gain does it too. So do opioids, chronic heavy alcohol use, and prior anabolic steroid cycles, which can leave the system suppressed long after the last vial went in the trash.

Fix the fixable thing first. It's slower and less exciting than a prescription and it works on the cause.

One more thing worth knowing before you start anything: testosterone therapy suppresses your body's own production and can impair fertility, sometimes durably. If your family isn't finished, that conversation belongs at the front of the appointment, not the end. Ask about it explicitly. There are approaches that account for it, and a urologist or endocrinologist is the person to raise it with.

None of this is medical advice and none of it substitutes for the doctor who can examine you. It's a better appointment, which is a genuinely different thing from a better internet search.

Set the alarm, skip breakfast, get stuck at 7:40, and then do the unglamorous part and go back the following week for the second one. The men who get good answers are almost always the men who went twice.