Know what to test. Then order it.
Plain-English guides to the blood tests worth asking about, plus a side-by-side look at the sellers that let you order without a doctor visit.
Start with your goal
Lipid panel
Total cholesterol, LDL, HDL, and triglycerides in one draw.
Read the guideApoB
Counts the artery-clogging particles in your blood.
Read the guideLipoprotein(a), or Lp(a)
An inherited risk factor most people have never been tested for.
Read the guideHigh-sensitivity CRP
A low-grade inflammation marker linked to heart risk.
Read the guideHemoglobin A1C
Your average blood sugar over about three months.
Read the guideComprehensive metabolic panel
14 markers for kidneys, liver, blood sugar, and electrolytes.
Read the guideComplete blood count
Red cells, white cells, hemoglobin, and platelets.
Read the guideTSH
The first-line check for an underactive or overactive thyroid.
Read the guideVitamin D, 25-hydroxy
Checks whether you have enough vitamin D for bones and muscle.
Read the guideVitamin B12
Checks B12 for fatigue, tingling, and anemia questions.
Read the guideFerritin
Shows your body's iron stores.
Read the guideTestosterone, total
Checks total testosterone when symptoms suggest it may be low.
Read the guideHeart health panel
The blood tests that give the clearest read on cardiovascular risk.
Read the guideAnnual physical blood work
A solid baseline: CBC, CMP, lipids, A1C, and thyroid.
Read the guideHow ordering works
Pick your tests
Read the guide so you know what the result can and cannot tell you.
Order online
Choose a seller, pay a fixed price, and get a lab order from an independent physician.
Visit a lab
Show the order at a partner lab. Most take walk-ins, and some let you book a time.
Get results
Results arrive online, often within 1 to 3 days. Take them to your clinician.
The heart panel most people never get
A standard cholesterol panel leaves out two numbers that can change the picture: ApoB, which counts plaque-forming particles, and Lp(a), an inherited risk factor that most adults have never checked.
See the heart health panelSellers we compare
We read each seller's own pages and report what they say about labs, ordering, and results. No seller pays to change what we write.
Open the comparisonCommon questions
Can I order a blood test without a doctor?
In most states, yes. Online lab sellers include an independent physician order in the price. You pay online, then visit a partner lab such as Quest or Labcorp for the draw. A few states restrict direct ordering, so check availability at checkout.
Do I need insurance?
No. You pay a fixed price online. Insurance does not apply to these orders, but you can often use HSA or FSA funds. Confirm with the seller.
How fast do I get results?
Most sellers report results in 1 to 3 days. Some tests, such as Lp(a), can take a few days longer.
Does Zenlo Health sell the tests?
No. We explain tests and compare sellers. When you click through and buy, the seller handles your order, the lab draw, and your results. We may earn a commission.
Are these tests accurate?
The same labs (Quest, Labcorp, and others) run these tests whether a doctor or an online seller orders them. Reference ranges differ by lab, so use the range printed on your report.