Ask Your Doctor for These Labs
Updated: Oct 3
Your annual physical offers an important look at how your body is functioning, but standard checkups often include only a limited number of labs and focus on whether results are simply “normal.”
Advanced Lipid Panel
What to ask for and what the numbers mean.
Total Cholesterol: Standard is less than 200 mg/dL. Optimal usually falls between 150 and 200 mg/dL, but this number is less meaningful on its own than the ratios and particle counts below.
LDL Cholesterol (“bad”): Standard is less than 100 mg/dL. Optimal is often less than 100 mg/dL, and closer to less than 70 to 80 mg/dL if you have other risk factors
HDL Cholesterol (“good”): Standard is greater than 40 mg/dL for men and greater than 50 mg/dL for women. Optimal is greater than 60 mg/dL.
Triglycerides: Standard is less than 150 mg/dL. Optimal is less than 100 mg/dL, and ideally closer to 70 to 90 mg/dL.
Triglyceride to HDL Ratio (a hidden gem): Divide your triglycerides by your HDL. A ratio below 2.0 is considered optimal, and below 1.5 is ideal. Higher ratios are one of the earliest signs of insulin resistance
ApoB (Apolipoprotein B): This measures the actual number of cholesterol-carrying particles that can drive plaque buildup, and it is often a more accurate predictor of heart disease risk than LDL alone. Standard upper limit is 130 mg/dL. Optimal is below 80 mg/dL, and below 60 to 70 mg/dL if you have other cardiovascular concerns
Lipoprotein(a), or Lp(a): A genetic marker worth checking at least once in your lifetime. Optimal is less than 30 mg/dL (or less than 75 nmol/L).
Blood Sugar and Insulin
Most physicals check fasting glucose and sometimes HbA1c, but by the time these numbers rise, insulin resistance has often been developing for years. Adding fasting insulin gives you a much earlier window.
Fasting Glucose: Standard is 70 to 99 mg/dL. Optimal is 72 to 85 mg/dL.
HbA1c (average blood sugar over three months): Standard is less than 5.7 percent. Optimal is less than 5.4 percent, with many practitioners aiming for 4.8 to 5.2 percent.
Fasting Insulin: Rarely ordered but incredibly informative. Standard “normal” often extends to 25 uIU/mL, but optimal is 2 to 6 uIU/mL. Elevated fasting insulin can signal insulin resistance well before glucose rises.
HOMA-IR (calculated from fasting glucose and insulin): This score tells you how insulin sensitive you are. Below 1.0 is optimal, below 1.9 is considered normal, and 2.0 or higher suggests insulin resistance is developing.
Blood Pressure
These are not lab draws, but they are simple in-office measurements that provide essential context for everything else on your panel.
Blood Pressure: Standard “normal” is less than 130/80 mmHg. Optimal is less than 120/80 mmHg
Resting Heart Rate: A resting heart rate of 60 to 70 beats per minute generally reflects good cardiovascular fitness.
Inflammation Markers
Chronic, low-grade inflammation is a common thread linking heart disease, insulin resistance, autoimmune conditions, and even mood changes. Two simple labs can help you see it.
hs-CRP (high-sensitivity C-reactive protein): Standard interpretation is less than 1.0 mg/L low risk, 1.0 to 3.0 average risk, and greater than 3.0 higher risk. Optimal is less than 1.0 mg/L, and ideally less than 0.5 mg/L
Homocysteine: Standard normal reaches up to 15 umol/L, but optimal is less than 7 to 8 umol/L. Elevated levels can point to a need for more B12, folate, or B6, and are linked to both cardiovascular and cognitive risk
GGT (gamma-glutamyl transferase): A liver enzyme that also reflects oxidative stress and metabolic health. Standard upper limit is often 40 to 60 U/L, but optimal is less than 16 to 20 U/L, especially for reducing metabolic syndrome risk
Vitamin D
Vitamin D acts more like a hormone than a vitamin. It supports immune function, bone health, mood, and metabolic regulation.
25-Hydroxy Vitamin D: Standard “sufficient” is often listed as greater than 20 or 30 ng/mL. Optimal is generally 40 to 60 ng/mL for most adults, with strong evidence supporting 36 to 50 ng/mL for cardiovascular and overall health benefits
The Extras Worth Requesting
These are the labs that often get skipped but can offer major insight, especially if you are experiencing fatigue, brain fog, hormonal changes, or unexplained symptoms.
Waist Circumference: Often overlooked, but very telling. Elevated risk begins at greater than 35 inches for women and greater than 40 inches for men. Waist size reflects visceral fat, which is one of the strongest drivers of metabolic dysfunction.
Full Iron Panel (ferritin, serum iron, TIBC, transferrin saturation):
Ferritin (iron storage): Standard ranges vary by laboratory. Optimal is 50 to 150 ng/mL for most adults. Ferritin ≤30 ng/mL generally indicates iron deficiency, while ≤50 ng/mL may be considered deficient when symptoms or risk factors are present. Because inflammation can raise ferritin, TSAT (transferrin saturation) should also be considered. With inflammation, iron deficiency may be present when ferritin is <100 ng/mL or TSAT <20%.
Serum Iron: Optimal is 70 to 130 mcg/dL.
Transferrin Saturation: Optimal is 25 to 35 percent.
RBC Magnesium: Standard serum magnesium misses most deficiencies. RBC magnesium is more accurate. Optimal is 6.0 to 6.5 mg/dL
Vitamin B12: Standard is greater than 200 pg/mL, but optimal is greater than 500 to 700 pg/mL, especially if you are plant-based or over 50.
Folate: Optimal is greater than 12 to 15 ng/mL.
Uric Acid: Standard reaches up to 7 mg/dL for men and 6 mg/dL for women, but research increasingly supports keeping it below 5.5 mg/dL for metabolic health
Full Thyroid Panel (TSH, Free T4, Free T3, and thyroid antibodies TPO and TG): TSH is often the only test ordered, but a full panel gives a much clearer picture. Optimal TSH for most people who feel well is 1.0 to 2.0 mIU/L, with Free T4 above 1.1 ng/dL and Free T3 above 3.2 pg/mL
Comprehensive Metabolic Panel (CMP): Includes liver enzymes (ALT, AST), kidney markers (BUN, creatinine, eGFR), and electrolytes. Optimal ALT and AST are usually less than 25 U/L.
Complete Blood Count (CBC): Helps identify anemia, immune changes, and hydration status.
Conclusion
You do not need to run every single test at once, and you certainly do not need to feel overwhelmed by the list. Think of these labs as tools that help you and your provider build a fuller, more personalized picture of your health. Optimal ranges help identify opportunities for gentle, sustainable change well before a diagnosis is made. When you understand your numbers within the context of your whole life, including how you eat, move, rest, and connect, you gain a powerful roadmap for supporting long-term metabolic health.
Three Action Steps You Can Take Today
Bring it to your next annual physical. Let your provider know you would like to understand your metabolic health beyond the basics and ask which of these labs make sense for you.
Add one fiber-rich food to your day.
A handful of berries, a scoop of chia seeds, or a side of lentils can gently support blood sugar, cholesterol, and inflammation all at once.
Take a 10-minute walk after your largest meal.
Post-meal movement is one of the most well-studied and gentle ways to improve blood sugar and insulin sensitivity.
References
Institute for Functional Medicine. Advanced Lipid Testing and Cardiovascular Health. https://www.ifm.org/articles/advanced-lipid-testing-cardio-health
Gayoso-Diz P, et al. Insulin resistance (HOMA-IR) cut-off values and the metabolic syndrome. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC4016563/
American Heart Association. Clinical Usefulness of Very High and Very Low Levels of C-Reactive Protein. https://www.ahajournals.org/doi/10.1161/01.cir.0000125690.80303.a8
ZRT Laboratory. Vitamin D: What Level is Normal vs Optimal? https://www.zrtlab.com/blog/archive/vitamin-d-reference-ranges-optimal/
Cleveland Clinic. Homocysteine: Function, Levels & Health Effects. https://my.clevelandclinic.org/health/articles/21527-homocysteine
OptimalDX. Optimal GGT Levels: More Than a Liver Enzyme. https://www.optimaldx.com/blog/ggt-much-more-than-a-liver-enzyme
Johns Hopkins Medicine. Metabolic Syndrome. https://www.hopkinsmedicine.org/health/conditions-and-diseases/metabolic-syndrome
Effect Doctors. Optimum vs Normal Iron Levels in Women. https://effectdoctors.com/blog/optimum-vs-normal-iron-levels-women/
Xu Y, et al. The optimal healthy ranges of thyroid function. PMC. https://pmc.ncbi.nlm.nih.gov/articles/PMC10866328/
Great post