Free testosterone assessment · no account · about 5 minutes
How much testosterone are you probably making?
Two short questionnaires. The first is the 17-question AMS scale that clinics hand you. The second asks about your body, sleep and habits, which is what actually predicts the number. You get an estimate in ng/dL, the odds you'd test low, and the free changes that would move it most.
Rate how much each symptom has bothered you recently, compared with how you used to be. There are no right answers; go with your first instinct.
What you get
- 01An estimate in ng/dL (and nmol/L), with a likely range instead of a single false-precision number.
- 02Your odds of testing below 300 ng/dL, the line most doctors use, so you know whether a blood test is worth the morning.
- 03What's driving it, factor by factor: age, waist, sleep, drink, medications, symptoms.
- 04Your biggest levers, ranked by how much each is expected to move your number, with the protocol for each. None of them require buying a product.
Tcheck is built by the team behind All Day Fire, a tongkat ali supplement. The assessment is free, sells nothing, and stays that way. Your answers are kept on this device only, unless you choose to subscribe at the end. It is an estimate for education, not a diagnosis; only a morning blood test gives you the real number.
Part 1 complete · your AMS score
By domain
What the score means, and what it doesn't
Clinics use the AMS to decide whether to look further. Scores of 27 and above count as symptomatic, and the cut-offs above are the official ones. The scale was built to track how a man feels over time, not to measure his hormones. Men with high scores are somewhat more likely to test low, but plenty of men with severe symptoms have normal testosterone, and many men with low testosterone feel fine. Four items do carry real signal: beard growth, sexual performance, morning erections and desire. Those feed into Part 2.
Your result
Estimate · not a lab resultEstimated total testosterone
If you took a morning blood test, the chance it lands…
What's driving it
Starting point: a healthy, lean man in his twenties measures about 490 ng/dL on the harmonized reference scale. Each line below moves that up or down. Tap a line for the reasoning.
Your biggest levers
Gains are expected effects for a typical man with your profile, from population studies. They add up imperfectly, and your own response will differ. The full ranked list, with evidence, is in the playbook.
Get the real number
The estimate tells you whether a blood test is worth the morning. The test tells you the truth. It takes ten minutes and, in most countries, costs less than a decent dinner.
- Book it for 7 to 10 am.Testosterone peaks in the morning and falls through the day; afternoon results read low and get dismissed. Night-shift workers: within three hours of waking.
- Ask for the right panel.Total testosterone (LC-MS/MS method if offered), SHBG and albumin so free testosterone can be calculated, plus LH and FSH. Add HbA1c and a lipid panel while you're there.
- Go fasting, rested, not sick.Skip the hard workout the day before, no heavy drinking that week, and don't test during an illness. All three push the number down.
- Get the number, not "normal".Ask for the value and the reference range. "Normal" can mean 265 or 900.
- Repeat it once.Day-to-day variation is 15–20%. Guidelines require two low morning readings before anyone calls it low.
Bring your AMS score and this estimate to the appointment. The blood test guide has the thresholds and what each marker means.
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A plan built around your top levers, a reminder to retake the AMS at week 8, and the research as it comes out. No supplements required, no selling in the plan.
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First email arrives within a day. Retake both parts in eight weeks; the link in that email brings you back here.
Separate project · disclosure
Curious about tongkat ali?
It's the one herb with repeated human trials behind it: in several small studies, 200–400 mg a day of a standardized extract raised total testosterone by a modest amount, mostly in older men and men who started low. It is not a substitute for the levers above. If you want to try it, we make All Day Fire tongkat ali capsules: every batch lab tested for purity, and encapsulated in an NSF certified GMP facility in the US.
For education only. This estimate is a statistical guess from population studies; it cannot diagnose anything. Decisions about testosterone belong with you and a doctor who has your blood work. See how it's calculated.
The playbook
What moves testosterone, ranked
Everything here is free or close to it: food, sleep, training, and a few generic supplements only if a blood test says you're short. Expected effects are for a typical man who has that lever available. If your waist is already lean, the waist lever isn't yours.
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Shrink your waist
Expected: +5–8% per 5 cm (2 in) off the waist · roughly +80 ng/dL for a 10% weight loss when overweight
Belly fat is the single biggest controllable factor. It converts testosterone to estrogen, drives insulin resistance, and dampens the signal from the brain to the testes. Waist tracks it better than the scale does.
- Eat 300–500 kcal a day below maintenance, from food, not by skipping meals. Faster than 1 kg (2 lb) a week starts to cost testosterone.
- Protein around 1.6 g per kg of bodyweight a day so the loss is fat, not muscle.
- 8–10k steps a day plus two or three lifting sessions a week.
- Measure the waist at the navel every two weeks; aim for under half your height.
Evidence: Corona 2013 meta-analysis (diet-induced weight loss +2.9 nmol/L); Svartberg 2004, Tromsø (waist the strongest anthropometric correlate); Kumagai 2016 (activity volume drove the gain).
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Sleep seven to nine hours, on a schedule
Expected: +10–15% versus five-hour nights
Most testosterone is made during sleep. One week of five-hour nights dropped daytime levels by 10–15% in healthy young men, about the equivalent of ageing fifteen years.
- Fix the wake-up time first, seven days a week. Bedtime follows.
- Daylight within an hour of waking; dim, warm light the last hour before bed.
- No alcohol in the three hours before bed; it fragments the second half of the night.
- Cool, dark, quiet. A sleep mask and earplugs are allowed purchases.
- Loud snoring, witnessed pauses or waking unrefreshed: get checked for sleep apnea.
Evidence: Leproult & Van Cauter 2011, JAMA. Sleep apnea: consistently associated with low T; weight loss recovers more of it than CPAP alone.
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Lift two or three times a week
Expected: +2–5% directly · much more through a smaller waist and better insulin sensitivity
The spike after a heavy session is temporary and doesn't matter much. The lasting benefit is muscle, which soaks up glucose and shrinks the waist, which is where the hormone lives.
- Compound lifts: a squat or leg press, a hinge, a press, a row. Three or four sets of 5–10 reps, close to failure.
- Forty-five minutes is enough. Add weight slowly and keep a log.
- Two sessions a week beat five sessions in January and none in March.
Evidence: Kumagai 2016; resistance training in sedentary and overweight men raises resting T modestly, with the biggest gains in those who also lose fat.
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Eat enough fat, and don't crash-diet
Expected: avoids a 10–15% loss
Testosterone is built from cholesterol. Very low-fat diets (under about 20% of calories) lower total T by 10–15% in controlled trials, and a deep calorie deficit held for months does the same.
- Keep fat at 25–35% of calories: olive oil, eggs, nuts, dairy, fatty fish, meat.
- Deficit no larger than 500 kcal a day; take a week at maintenance every 8–12 weeks.
- Carbohydrates are fine. Protein high, fat adequate, the rest is preference.
Evidence: Whittaker & Wu 2021, meta-analysis of intervention studies.
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Drink less
Expected: +5–10% for heavy drinkers who cut to a week of seven or fewer
Alcohol is directly toxic to the cells that make testosterone and wrecks the sleep it's made in. Light drinking barely registers; three or more a day does.
- No more than two on any day, and three or four alcohol-free days a week.
- Nothing within three hours of bed.
- Heavy nights lower testosterone for a day or two afterwards. Count them.
Evidence: dose-dependent suppression in both acute and chronic drinking studies; recovers with abstinence.
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Fix deficiencies, and only deficiencies
Expected: meaningful only if you were low; otherwise nothing
Zinc, vitamin D and magnesium are all needed to make testosterone. Being short on any of them lowers it; taking more than enough does nothing. Test first, and buy the cheapest generic.
- Zinc: 11 mg a day from food (oysters, beef, pumpkin seeds, lentils). Supplement 15–25 mg only if intake is poor or a test is low.
- Vitamin D: get a 25-OH-D test; if under 20 ng/mL (50 nmol/L), 1,000–2,000 IU a day plus midday sun.
- Magnesium: 300–400 mg a day from food (greens, nuts, beans) or a cheap glycinate if you're short.
Evidence: Prasad 1996 (zinc deficiency); Pilz 2011 positive in deficient men, Lerchbaum 2017 null in replete men; Cinar 2011 (magnesium, small).
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Cap endurance volume, or fuel it
Expected: +10–30% for high-volume endurance athletes who recover
Men logging more than ten hours a week of running or cycling, especially while under-eating, develop measurably lower testosterone. It's an adaptation to energy stress, not a disease, and it reverses.
- Eat enough for the training. Under-fuelling is the real cause.
- Keep hard endurance work under 7–8 hours a week unless racing; add two lifting sessions.
- Sleep more than you think the training needs.
Evidence: Hackney 2020 review of the exercise-hypogonadal male condition.
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Review your medications
Expected: large, for the men it applies to
Regular opioids are among the strongest suppressors of testosterone known (about 165 ng/dL on average). Long-term prednisone and some antipsychotics also lower it. Finasteride raises total T slightly while lowering DHT. Never stop a medication on your own; ask the prescriber about alternatives and get tested.
Evidence: Bawor 2015 meta-analysis (opioids); glucocorticoid and prolactin-raising drug effects are long established.
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Get morning light and move during the day
Expected: small directly; it mostly works through sleep and waist
- Ten to twenty minutes outside within an hour of waking anchors the clock that times the morning testosterone peak.
- A ten-minute walk after meals and standing calls cut the sitting that feeds the waist.
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Manage chronic stress
Expected: modest; real when stress is wrecking sleep
Cortisol and testosterone run on opposite rails. The practical fixes are the ones already listed: sleep, training, daylight, less alcohol. Add whatever reliably lowers your own load, whether that's a walk, a conversation or a boundary.
What won't move it much
- Testosterone "boosters"
- Tribulus and D-aspartic acid have failed repeated trials in healthy men. Fenugreek and ashwagandha show small, inconsistent effects. Tongkat ali is the one with several positive small trials, mostly in older or low-starting men. None replaces the list above.
- Cold plunges
- No good evidence they raise testosterone. Cold straight after lifting may blunt muscle gains.
- Abstinence
- Masturbation and sex have no meaningful effect on resting levels in either direction.
- Soy
- A meta-analysis of trials found no effect of soy foods or isoflavones on testosterone in men.
- Quitting smoking
- Smokers measure slightly higher total T, mostly from higher SHBG; quitting is still the right call and is not expected to lower free testosterone meaningfully.
- A single heavy workout
- Raises testosterone for about an hour. By dinner it's gone. Train for the long-term effects.
Blood test guide
How to get a number you can trust
One badly timed test has sent plenty of men down the wrong road in both directions. Here's how to do it properly, what to order, and how to read it.
Before the draw
- Morning, 7 to 10 am.Levels fall 20–30% from morning to late afternoon in younger men. If you work nights, go within three hours of waking and tell the lab.
- Fasting, after a normal night's sleep.A big meal lowers the reading for a few hours; one short night lowers it more.
- Not after a hard session, a heavy night, or while ill.Any of the three can shave 10–20% off.
- Two mornings, a week or more apart.Guidelines require two low readings before diagnosis, because a single value bounces 15–20% day to day.
What to order
| Marker | Why | Typical reference |
|---|---|---|
| Total testosterone LC-MS/MS method if offered | The headline number. Immunoassays are fine above 300 but drift at the low end. | 264–916 ng/dL 9.2–31.8 nmol/L |
| SHBG | The protein that binds most testosterone. High SHBG (age, liver, thyroid, low insulin) means less is free to act; low SHBG (obesity, insulin resistance) hides a low free level behind a normal total. | 10–57 nmol/L |
| Albumin | With SHBG and total T, lets the lab calculate free testosterone, which matters more for symptoms. | 3.5–5.0 g/dL |
| Calculated free T | Below about 65 pg/mL (225 pmol/L) is low on most calculators, even when total looks fine. | > 65 pg/mL |
| LH and FSH | Tell you where a low number comes from. High LH with low T points at the testes; low or normal LH with low T points at the brain, weight, sleep or medication, which is the reversible kind. | LH 1.7–8.6 IU/L |
| Prolactin | If LH is not raised. High prolactin suppresses testosterone and is treatable. | < 20 ng/mL |
| HbA1c, lipids, hematocrit | Context. Insulin resistance is the most common reversible cause; hematocrit matters if anyone later suggests treatment. | A1c < 5.7% |
Reference ranges vary by lab and method. The harmonized total-T range above comes from four large cohorts of healthy non-obese men aged 19–39 (Travison 2017). Quest and LabCorp now both use it or something close.
Reading it
- ATotal under 264–300 ng/dL on two mornings, with symptoms: that's the territory where guidelines say a doctor should work it up. Ask about causes (weight, sleep apnea, medications, LH/FSH) before anyone offers a prescription.
- BTotal 300–400 with symptoms: "low-normal." Check calculated free T and SHBG. This is where the levers in the playbook pay off most, and a retest in three months after working them is the sensible move.
- CTotal above 400–450, symptoms anyway: testosterone is probably not your problem. Sleep, mood, thyroid, iron and the rest of the usual suspects deserve a look.
- DAny result from an afternoon draw: repeat it in the morning before believing it.
Costs: direct-to-consumer labs in the US run roughly $40–80 for total T plus SHBG; most European and Asian clinics are similar or cheaper. In Japan a men's clinic will often run the AMS on paper before drawing blood, which is the same Part 1 you can take here.
Method
How the estimate is calculated
No model can read your blood from a questionnaire. What a model can do is combine what population studies know about age, body fat, sleep, drink, illness, medication and symptoms into an honest probability. That is what Tcheck does, and it shows its work.
Starting point
Healthy, non-obese men aged 19–39 have a harmonized reference range of 264–916 ng/dL (2.5th to 97.5th percentile, Travison 2017). Fitting a log-normal curve to that gives a median of about 490 ng/dL and a spread (log standard deviation) of about 0.32. Every estimate starts there.
Factors
Each answer multiplies the starting point by an effect size taken from the literature, applied on a log scale so they combine the way the biology does.
| Factor | Effect used | Main sources |
|---|---|---|
| Age | −0.5% per year after 30 | EMAS (Wu 2008): healthy ageing alone is a small effect; most of the apparent decline is weight and illness. |
| Waist-to-height ratio | −2.5% per 0.01 above 0.47 | Svartberg 2004; EMAS; NHANES. About −25% at a waist of 0.58× height, the typical obese range. |
| BMI (if no waist) | −3.5% per point above 24 | Same sources; BMI is the fallback because waist predicts better. |
| Sleep | −3% (6–7 h) to −13% (under 5 h) | Leproult & Van Cauter 2011. |
| Snoring / apnea | −3% to −8% | Observational studies of OSA; partly overlaps with weight. |
| Resistance training | −2% to +3% | Small direct effect; most of the benefit arrives through the waist. |
| Endurance volume | −3% (7–12 h) to −10% (12 h+) | Hackney 2020. |
| Alcohol | −2% to −10% | Dose-dependent suppression studies. |
| Smoking | +7% (total T only) | EMAS; Tromsø. Reflects higher SHBG; counted, not recommended. |
| Aggressive cut / very low fat | −8% / −10% | Whittaker & Wu 2021. |
| Type 2 diabetes / prediabetes | −10% / −4% | Dhindsa 2004, 2010: independent of BMI. |
| Serious chronic illness | −15% | Inflammatory suppression of the axis. |
| Testicular history | −20%, wider uncertainty | Raises the chance of primary hypogonadism; only LH/FSH can tell. |
| Opioids / steroid pills / antipsychotics | −40% / −25% / −15% | Bawor 2015 meta-analysis; glucocorticoid and prolactin literature. |
| Finasteride, dutasteride | +8% | Blocked conversion to DHT. |
| Anabolic steroids or TRT in the last year | −45%, much wider uncertainty | Suppressed own production; recovery takes months. |
| AMS symptoms | −1.5% per severity point on the four androgen-specific items; −0.15% per point on the other 13 | Wu 2010 (EMAS, NEJM): sexual symptoms are the ones that track low T, with odds roughly doubling to tripling when all are present. The rest of the scale barely predicts the hormone. |
Lifestyle, health and symptom effects overlap with each other and with body fat in real life, so their combined effect is shrunk by 20% before it is applied. Age, body and medication effects are applied in full.
Uncertainty
The spread starts at the population's own (0.32 on the log scale) and widens when the picture is unusual: a stack of several penalties, a testicular history, recent steroid use. If you enter a past lab value, the estimate is blended toward it, with more weight the more recent it is, and the spread narrows. The "likely range" shown is the middle 50%; the odds are the share of that distribution falling below 300 ng/dL (the AUA threshold), between 300 and 500, and above 500.
What this is not
It is not a diagnosis, a free-testosterone estimate (that needs SHBG), or a substitute for the morning blood test it keeps telling you to get. It is a well-sourced guess with its uncertainty shown, which is more than most online "T tests" offer.
Sources
- Travison TG et al. Harmonized reference ranges for circulating testosterone levels in men of four cohort studies in the United States and Europe. J Clin Endocrinol Metab, 2017.
- Wu FCW et al. Hypothalamic-pituitary-testicular axis disruptions in older men are differentially linked to age and modifiable risk factors: the European Male Aging Study. J Clin Endocrinol Metab, 2008.
- Wu FCW et al. Identification of late-onset hypogonadism in middle-aged and elderly men. N Engl J Med, 2010.
- Heinemann LAJ et al. A new "Aging Males' Symptoms" (AMS) rating scale. The Aging Male, 1999.
- Corona G et al. Body weight loss reverts obesity-associated hypogonadotropic hypogonadism: a systematic review and meta-analysis. Eur J Endocrinol, 2013.
- Svartberg J et al. Waist circumference and testosterone levels in community dwelling men. The Tromsø study. Eur J Epidemiol, 2004.
- Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA, 2011.
- Whittaker J, Wu K. Low-fat diets and testosterone in men: systematic review and meta-analysis of intervention studies. J Steroid Biochem Mol Biol, 2021.
- Dhindsa S et al. Frequent occurrence of hypogonadotropic hypogonadism in type 2 diabetes. J Clin Endocrinol Metab, 2004.
- Bawor M et al. Testosterone suppression in opioid users: a systematic review and meta-analysis. Drug Alcohol Depend, 2015.
- Hackney AC. Hypogonadism in exercising males: dysfunction or adaptive-regulatory adjustment? Front Endocrinol, 2020.
- Kumagai H et al. Increased physical activity has a greater effect than reduced energy intake on lifestyle modification-induced increases in testosterone. J Clin Biochem Nutr, 2016.
- Prasad AS et al. Zinc status and serum testosterone levels of healthy adults. Nutrition, 1996.
- Pilz S et al. Effect of vitamin D supplementation on testosterone levels in men. Horm Metab Res, 2011; Lerchbaum E et al. Vitamin D and testosterone in healthy men: a randomized controlled trial. J Clin Endocrinol Metab, 2017.
- Bhasin S et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab, 2018.
- Mulhall JP et al. Evaluation and management of testosterone deficiency: AUA guideline. J Urol, 2018.
- Leisegang K et al. Eurycoma longifolia (Jack) improves serum total testosterone in men: a systematic review and meta-analysis of clinical trials. Medicina, 2022.