The 7 Labs Worth Running Before You Try Anything

If you are over 35 and thinking about testosterone therapy, peptides, or a new supplement stack, the smartest first move is not a purchase. It is a blood draw. The 7 labs worth running before you try anything give you two things no protocol can hand you: a real baseline, and a shot at finding the actual reason you feel flat. 

Fatigue, low libido, stubborn midsection fat, and slow recovery all have long lists of causes. Several of them are cheap to rule out, and several are genuinely fixable once you know they are there.

Below you will find which labs matter, how to time your draw so the numbers mean something, what the current clinical guidelines actually say, and what to do with the results.

Quick Summary

• Test before you treat. Symptoms like low energy, low libido, and low mood are common in aging men and have many possible causes, so they are not diagnostic on their own.

• Draw blood in the early morning, ideally between 7 and 10 a.m., after at least 8 hours of fasting. Timing changes the result.

• Testosterone requires two separate early-morning measurements before any diagnosis. The American Urological Association uses a total testosterone below 300 ng/dL as a reasonable cut point, and the Endocrine Society notes a common clinical threshold near that same number.

• The seven core labs: sex hormones with SHBG, LH and FSH, fasting glucose with A1c and insulin, TSH with free T4, CBC plus a comprehensive metabolic panel, ferritin with iron studies, and a lipid panel including a once-in-a-lifetime Lp(a).

• IGF-1 is a useful reference number, not a diagnosis. A normal IGF-1 does not rule out growth hormone deficiency, and a low one has many everyday causes.

• Reversible contributors get checked first. The Endocrine Society flags excess body weight, corticosteroids, and opioid use among them, and notes that for hypogonadism tied to a BMI above 27 with no other cause, weight loss is typically first-line.

• Get your baseline before you start anything hormonal. Exogenous testosterone suppresses your own production, and once you begin, that clean starting picture is gone.

Why blood work comes before any protocol

There is a pattern in men's health that costs people years. A guy turns 38, notices his energy and drive have slipped, reads a few threads, and starts something. Sometimes it is a peptide he ordered online. Sometimes it is a clinic that prescribes testosterone off a single afternoon lab. Sometimes it is a stack of six supplements at once.

Six months later he feels roughly the same, he has no idea which variable mattered, and he never found out that his ferritin was 900 or his A1c was 6.1.

Blood work solves three problems at once. It rules out the treatable things that mimic low testosterone. It gives you a reference point to measure change against. And it catches the handful of findings that would make certain interventions a bad idea.

The Endocrine Society's July 2026 statement on testosterone therapy makes the point plainly: symptoms alone are not diagnostic, and clinicians need to rule out reversible contributors first. That is not a hedge. It is the difference between fixing a problem and covering one.

What labs should a man over 35 get before starting a supplement or hormone protocol?

A useful baseline panel includes total and free testosterone with SHBG, LH and FSH, fasting glucose with hemoglobin A1c and fasting insulin, TSH with free T4, a complete blood count and comprehensive metabolic panel, ferritin with transferrin saturation, and a lipid panel including lipoprotein(a). Draw all of it fasted, in the early morning, and repeat testosterone on a second morning.

How to prepare for your blood draw

Preparation is not optional here. Poor timing produces numbers that send men down the wrong path.

1. Book an early morning slot. Testosterone follows a daily rhythm and peaks in the morning. Guidelines call for early morning draws, generally between 7 and 10 a.m., with an exception for night shift workers who should discuss timing with their clinician.

2. Fast for at least 8 hours. Water is fine. The Endocrine Society recommends fasting morning measurement, and a 2013 study of 74 men in Clinical Endocrinology found that a 75-gram glucose load was associated with a roughly 25% drop in average testosterone that had not recovered two hours later. Later studies have not all replicated this, but fasting removes the variable entirely.

3. Skip the workout the day before. Hard training, especially heavy or prolonged sessions, can shift hormone and enzyme readings including creatine kinase and liver markers.

4. Sleep normally for a few nights first. Most daily testosterone release happens during sleep. A small controlled JAMA study of ten young men found that one week of five-hour nights lowered daytime testosterone by 10% to 15%, and sleep fragmentation and obstructive sleep apnea are both associated with lower levels.

5. Write down every supplement and medication you take. Include biotin, which interferes with many hormone immunoassays, plus any DHEA, ashwagandha, or over-the-counter product marketed for hormones.

6. Do not start anything new in the two weeks before testing. You want a clean picture, not a mid-experiment snapshot.

7. Use the same lab for follow-up. Assays vary between platforms enough to change your interpretation. Where possible, ask whether the lab's testosterone assay is CDC HoST certified, since the Endocrine Society specifically flags non-standardized assays as a driver of both over-diagnosis and under-diagnosis.

The 7 labs worth running before you try anything

1. Total testosterone, free testosterone, and SHBG

This is the anchor test, and it is also the one most commonly misread.

Total testosterone measures everything circulating. Sex hormone binding globulin, or SHBG, determines how much of that total is actually available to tissue. Free testosterone is the unbound fraction. Two men can share an identical total of 420 ng/dL and have very different free levels depending on SHBG, which rises with age and falls with obesity and insulin resistance.

What the guidelines say: the AUA uses a total testosterone consistently below 300 ng/dL across at least two early-morning draws as a reasonable cut point supporting a diagnosis of low testosterone, and requires symptoms or signs alongside it. The Endocrine Society's harmonized reference range for healthy nonobese men aged 19 to 39 runs from 264 to 916 ng/dL using CDC-standardized assays.

Two draws, not one. This matters more than almost anything else in this article. A single low result does not confirm anything.

2. LH and FSH, plus prolactin when indicated

If testosterone comes back low, LH and FSH tell you where the problem lives.

High LH with low testosterone points toward the testes. Low or low-normal LH with low testosterone points upstream, toward the pituitary or hypothalamus, and that is the pattern most often seen with excess body weight, opioid use, and poor sleep. The AUA guideline directs clinicians to measure LH in men with low testosterone, and to add prolactin when LH is low or low-normal.

That distinction changes everything about what happens next. Secondary patterns driven by weight, medication, or sleep are often at least partly reversible. That is a very different conversation from a primary testicular issue.

3. Fasting glucose, hemoglobin A1c, and fasting insulin

Metabolic health and hormonal health are not separate topics. They share the same wiring.

The ADA's 2026 Standards of Care recommend that diabetes and prediabetes testing begin no later than age 35 for everyone, and earlier for adults with overweight or obesity plus one risk factor. Standard thresholds:

• Fasting glucose of 100 to 125 mg/dL indicates impaired fasting glucose, and 126 mg/dL or higher meets the criterion for diabetes

• A1c of 5.7% to 6.4% indicates prediabetes, and 6.5% or higher meets the criterion for diabetes

Fasting insulin is the optional add-on, and it is worth understanding its limits. Insulin assays are not standardized across platforms, so HOMA-IR values are not directly comparable between labs, and cutoffs vary by population. NHANES has used a HOMA-IR of 2.5 or above to flag insulin resistance. It is not a diagnostic criterion for anything. It is most useful trended in the same lab with the same assay over time.

Still worth having. If your A1c is drifting and your fasting insulin is high, you have found something actionable, and you have found it before you spent a year chasing hormones.

4. TSH with free T4

Hypothyroidism produces almost exactly the symptom list men attribute to low testosterone: fatigue, weight gain, low mood, cold intolerance, brain fog.

Adult TSH reference ranges typically fall somewhere around 0.4 to 4.0 or 4.5 mIU/L, with free T4 roughly 0.7 to 1.8 ng/dL, though the number your lab prints takes precedence. High TSH with low free T4 suggests overt primary hypothyroidism. High TSH with normal free T4 is subclinical hypothyroidism, which is common, frequently mild, and sometimes transient. Mild abnormalities often need repeating before anyone acts on them.

Order both. TSH alone leaves you guessing.

5. Complete blood count and comprehensive metabolic panel

These two are the safety layer, and they are the ones men skip.

The CBC gives you hemoglobin and hematocrit. This is not academic. The AUA guideline calls for measuring hemoglobin and hematocrit before offering testosterone therapy because of polycythemia risk, and flags a baseline hematocrit above 50% as reason to investigate before starting. Anything you might take that raises red cell mass makes this number worth knowing first.

The CMP covers liver enzymes, kidney function, electrolytes, and albumin, which you also need for free testosterone calculations. The liver piece deserves attention. In the NIH-funded Drug-Induced Liver Injury Network, the share of drug-induced liver injury cases attributed to herbal and dietary supplements rose from about 7% in 2004 to 2005 to about 20% by 2013 to 2014.

Frequently implicated agents include anabolic steroids, green tea extract, garcinia cambogia, kratom, ashwagandha, turmeric, and multi-ingredient products.

If you are about to start taking something daily, know what your liver looked like beforehand.

6. Ferritin with transferrin saturation

This is the one nobody orders, and it is the reason I put it on the list.

Hereditary hemochromatosis is among the most common genetic conditions in people of Northern European ancestry. C282Y homozygosity, the genotype behind most clinical cases, is present in roughly 0.3% to 0.6% of Northern European ancestry populations and about 0.26% of the US population. Men are affected far more often than women, and symptoms typically show up after 40.

The early symptom list is the problem: weakness, lethargy, joint pain, and reduced sexual function. It reads like a low testosterone ad. Later, untreated iron overload can involve diabetes, liver disease, and hypogonadism, because iron deposits in the pituitary. Only about 10% of C282Y homozygotes go on to develop end-organ damage, but diagnosis is often delayed, and screening runs on two inexpensive tests: serum ferritin and transferrin saturation.

Low iron matters too. Iron deficiency is a straightforward cause of fatigue and exercise intolerance, and in men it always warrants a look for a source of blood loss.

7. Lipid panel with lipoprotein(a) and selective ApoB

The March 2026 ACC/AHA multisociety dyslipidemia guideline changed what a good lipid workup looks like, and most content on this topic has not caught up.

Lipoprotein(a) should now be measured at least once in adulthood. It carries a Class I recommendation, which is the strongest designation the guideline uses. Lp(a) is largely genetically determined and stays fairly stable across life, so repeat testing is generally unnecessary.

A level of 125 nmol/L or higher, roughly 50 mg/dL, is associated with about a 1.4-fold increase in long-term heart attack and stroke risk, and 250 nmol/L with at least double.

ApoB is more selective. The guideline positions it as useful for assessing residual risk and guiding therapy once LDL-C and non-HDL-C goals are met, particularly with triglycerides at or above 150 mg/dL, diabetes, or a low achieved LDL-C.

You are testing once. Get the number that only needs testing once.

Reference points at a glance

Reference ranges differ between laboratories and assays. Interpretation belongs with a clinician who has your full history in front of them.

What about IGF-1 and growth hormone testing?

This one deserves an honest answer, since we work in the growth factor space and it would be easy to oversell it.

IGF-1 is worth measuring as a baseline reference number. Unlike growth hormone, which pulses through the day and is nearly impossible to interpret from a single draw, IGF-1 stays relatively stable and reflects average GH exposure. Ask for an age-adjusted result, because the reference range shifts substantially by decade.

Here is what IGF-1 cannot do. A normal IGF-1 does not exclude adult growth hormone deficiency. The Endocrine Society's guidance on adult GH deficiency is explicit on that point, and diagnosis in adults generally requires GH stimulation testing rather than a static IGF-1 value.

Going the other direction, a low IGF-1 has plenty of ordinary explanations, including undernutrition, poorly controlled diabetes, liver disease, and hypothyroidism. Clinical guidance also advises against pursuing GH stimulation testing in people who simply have nonspecific fatigue and weakness with no history of pituitary injury or disease.

So treat IGF-1 as a data point you can track, not a verdict. If it comes back well below the age-adjusted range, that is a conversation with an endocrinologist, not a reason to buy something.

Three more labs worth discussing with your clinician

These are situational rather than universal, which is exactly why they belong in a conversation rather than a default panel.

• PSA if you are over 40 and considering testosterone therapy. The AUA guideline calls for PSA measurement in men over 40 before starting testosterone therapy to exclude a prostate cancer diagnosis. If it is elevated, a repeat is recommended before anyone draws conclusions.

• Estradiol using a sensitive assay. Standard immunoassays are unreliable at the low concentrations found in men. If estradiol is being measured at all, an LC-MS/MS or otherwise sensitive method is the one worth running.

• 25-hydroxyvitamin D, with a caveat. The Endocrine Society's 2024 vitamin D guideline suggests against routine 25(OH)D screening in generally healthy adults, largely because trials have not established what target level actually produces a benefit. Testing still makes sense when there is a specific indication such as malabsorption, abnormal calcium, osteoporosis, or certain medications. If you are simply looking to cover baseline intake rather than chase a number, a maintenance-dose product like BioPro PM's companion BioPro D3-K2 pairs vitamin D3 with K2 for that purpose, and it is worth mentioning to your clinician alongside everything else you take.

What to do once your results come back

Resist the urge to act on every flagged value at once. Sequence matters.

1. Repeat anything borderline. Testosterone specifically requires a second morning draw. Mild TSH elevations often need repeating too.

2. Deal with reversible contributors first. The Endocrine Society notes that for hypogonadism attributable to overweight or obesity above a BMI of 27 with no other identified cause, weight loss is typically first-line therapy. Corticosteroids, opioids, untreated sleep apnea, and chronic short sleep belong in the same category.

3. Chase abnormal safety labs before starting anything. High ferritin, elevated liver enzymes, a hematocrit over 50%, or an unexpected anemia all need explanations, not workarounds.

4. Fix the metabolic picture in parallel. Prediabetes on your panel is a finding you can move within months, and it will not be solved by a hormone.

5. Then decide on interventions, with the trade-offs in front of you. The TRAVERSE trials, involving more than 5,200 men, found no meaningful increase in heart attack or stroke over one to four years. Those same trials showed roughly a 50% relative increase in pulmonary embolism and more fractures in testosterone-treated men, and long-term prostate safety remains unestablished. Real decisions require real numbers on both sides.

6. Set a re-test date. Ninety days is a reasonable interval for most metabolic and hormonal markers. Same lab, same conditions.

Where BioPro+ fits in

We build a supplement, so it is worth being direct about what a supplement is and is not.

BioPro+ is a sublingual, non-synthetic formula built around a proprietary elk antler velvet extract, shilajit, and functional botanicals including aloe vera, lycium, and tribulus. It is designed to support everyday physiological function: energy, recovery, sleep quality, and general vitality. Men choose it because it is drug-free, needle-free, requires no prescription, and takes ten seconds a morning rather than a clinic visit.

What it is not is a substitute for the work described above. BioPro+ does not diagnose anything, does not correct an abnormal lab value, and is not a replacement for medical evaluation.

If your ferritin is 950 or your A1c is 6.3, that needs a clinician, not a supplement. And on the ingredient science specifically, we hold ourselves to the actual evidence: human randomized trials have not consistently shown that oral or sublingual antler velvet raises circulating IGF-1, and shilajit's human metabolic data is still preliminary. Most of the supporting research on these ingredients is preclinical and mechanistic.

The honest framing is this. Labs tell you what is happening. Sleep, training, nutrition, and body composition move the biggest levers. BioPro+ is what a lot of men use for daily system support once the diagnostics are clear and the foundations are handled.

These statements have not been evaluated by the Food and Drug Administration. BioPro+ is not intended to diagnose, treat, cure, or prevent any disease.

Mistakes men make with their first panel

• Drawing blood in the afternoon, then acting on a low testosterone result

• Accepting a diagnosis from a single measurement instead of two morning draws

• Ordering total testosterone without SHBG or free testosterone

• Skipping LH and FSH, which means skipping the question of why

• Ignoring thyroid and metabolic markers because the symptoms sounded hormonal

• Starting testosterone or hCG before establishing a baseline, which permanently removes the ability to know what your natural production was

• Switching labs between tests and comparing numbers that were never comparable

• Changing five variables at once, then having no idea which one worked

The takeaway

The 7 labs worth running before you try anything cost less than one month of most protocols and answer questions no protocol can. Sex hormones with SHBG. LH and FSH. Glucose, A1c, and insulin. TSH with free T4. CBC and CMP. Ferritin with transferrin saturation. Lipids with a once-in-a-lifetime Lp(a).

Your practical next steps: book an early-morning fasted draw, bring the list above to your clinician or order it through a reputable lab, schedule the second testosterone draw for a separate morning two to three weeks later, and hold off on starting anything new until you have both sets of results in hand.

You are going to spend money and months on this either way. Spend the first two hundred dollars on knowing what is actually going on.

Frequently Asked Questions

What time of day should I get my testosterone tested?

Early morning, generally between 7 and 10 a.m., after at least 8 hours of fasting. Testosterone follows a daily rhythm and peaks in the morning, and levels can fall meaningfully by afternoon. Both the AUA and the Endocrine Society specify early-morning measurement, and both require a second confirmatory morning draw before any diagnosis is made. Night shift workers should discuss appropriate timing with their clinician.

How many times do I need to test testosterone before starting TRT?

At least twice, on separate mornings. The AUA guideline calls this a strong recommendation, and the Endocrine Society's 2026 statement reiterates that diagnosis should rest on at least two early-morning fasting tests. A single low reading is not enough. Levels vary day to day, assays vary between labs, and acting on one number is how men end up on lifelong therapy they may not have needed.

Do I need blood work before taking a supplement, or only before hormones?

Baseline labs are worth running before either. A comprehensive metabolic panel and CBC establish your liver, kidney, and blood picture before you add anything daily, which matters because the share of drug-induced liver injury cases attributed to herbal and dietary supplements in the US Drug-Induced Liver Injury Network rose from roughly 7% to 20% over a decade. Baseline labs also let you tell whether something is actually working.

Should I get my IGF-1 tested before trying growth factor support?

It is a reasonable baseline to have, since IGF-1 is stable through the day and reflects average growth hormone exposure, but understand its limits. A normal IGF-1 does not rule out adult growth hormone deficiency, and diagnosing that condition typically requires GH stimulation testing rather than a single IGF-1 value. Low IGF-1 also has common non-pituitary causes including undernutrition, liver disease, and hypothyroidism. Ask for an age-adjusted result.

What labs should I check for fatigue that is not low testosterone?

Start with thyroid function (TSH plus free T4), fasting glucose and hemoglobin A1c, a complete blood count to rule out anemia, ferritin and transferrin saturation to check for iron deficiency or iron overload, and a comprehensive metabolic panel for liver and kidney function. Sleep is worth evaluating too, since the majority of daily testosterone release occurs during sleep and obstructive sleep apnea is associated with lower levels.

Sources

• Endocrine Society, Statement on Testosterone Replacement Therapy, July 2026: endocrine.org

• Endocrine Society, Testosterone Therapy in Men With Hypogonadism Clinical Practice Guideline, JCEM 2018

• American Urological Association, Evaluation and Management of Testosterone Deficiency Guideline

• American Diabetes Association, Standards of Care in Diabetes 2026, Section 2

• 2026 ACC/AHA Multisociety Guideline on the Management of Dyslipidemia, JACC and Circulation

• Endocrine Society, Vitamin D for the Prevention of Disease Clinical Practice Guideline, JCEM 2024

• Endocrine Society, Evaluation and Treatment of Adult Growth Hormone Deficiency Clinical Practice Guideline, JCEM

• Caronia LM et al., Abrupt decrease in serum testosterone levels after an oral glucose load in men, Clinical Endocrinology 2013

• Leproult R, Van Cauter E, Effect of 1 Week of Sleep Restriction on Testosterone Levels in Young Healthy Men, JAMA 2011

• Navarro VJ et al., Liver injury from herbals and dietary supplements in the US Drug-Induced Liver Injury Network, Hepatology 2014

• Crownover BK, Covey CJ, Hereditary Hemochromatosis, American Family Physician 2013

---

These statements have not been evaluated by the Food and Drug Administration. BioPro+ is not intended to diagnose, treat, cure, or prevent any disease. This content is for general educational purposes and is not medical advice. Consult a qualified healthcare provider before starting, stopping, or changing any supplement, medication, or hormone protocol.