How Long Does Blood Work Take?

The blood draw itself usually takes less than five minutes. Routine results such as a complete blood count (CBC) are often reported in 24 to 48 hours. Hormone panels commonly take 3 to 6 days, and some specialized tests take longer.

If you are being evaluated for testosterone replacement therapy, the diagnosis requires labs. The American Urological Association makes the diagnosis only after two early-morning total testosterone measurements plus symptoms or signs (AUA 2018). Morning timing matters for those draws; see when morning testosterone is highest.

How long does the blood draw itself take?

After the needle goes in, collecting the sample usually takes less than five minutes (MedlinePlus). Identifying the vein, filling the tubes, and checking that you can leave often takes one or two minutes (Mayo Clinic 2024). Extra vials add a little time. The chair visit is short; waiting for the appointment is usually the longer part.

How long until you get your results?

Labcorp, a large U.S. reference lab, reports many routine tests within 24 to 48 hours, including CBC, a basic metabolic panel (BMP), and most cholesterol tests. Men's and women's hormone panels typically take 3 to 6 days. Some results take up to two weeks, and genetic tests can take up to 21 days (Labcorp).

A hospital system may be faster on common counts. Norton Healthcare says CBC results are usually available to the ordering clinician within 24 hours, and that getting those results to you can still take hours, days, or weeks (Norton Healthcare 2024).

Factors that affect turnaround time include:

• Type of test. Routine blood counts and chemistry panels are faster than hormone or genetic assays.
• Transport time. Sending a sample to another facility adds time, because turnaround includes the trip to the lab that actually runs the test (Labcorp).
• How results are released. Some portals show results when the lab reports them. Others wait for a clinician to review them first. Norton asks patients to allow 24 to 48 hours for that review (Norton Healthcare 2024).

What you can do before the appointment

• Schedule early if you have to fast. Fasting is usually 8 to 12 hours of water only, so a morning appointment lets you sleep through most of it (MedlinePlus). Cholesterol tests are often done in the morning for the same reason (MedlinePlus).
• Use the lab your clinician ordered. If you are watching trends over time, using the same lab also makes results comparable (MedlinePlus).
• Follow prep instructions. Fasting or holding a medication when directed keeps the sample valid. If you eat before a fasting test, the lab may not run it and you will need another draw (Norton Healthcare 2024).

Frequently asked questions

How long does blood work take if I'm fasting? The fasting period (usually 8 to 12 hours) does not change how long the draw itself takes, only your prep time before the appointment (MedlinePlus).

Can I get same-day results? Some hospital labs return urgent CBCs the same day. At a large outpatient lab, routine CBC, BMP, and cholesterol tests are more often reported in 24 to 48 hours, not a few hours (Labcorp).

Do results take longer if I do blood work on a Friday? They can. Turnaround depends on the complexity of the test and how long it takes to get the sample to the lab that runs it (Labcorp). Ask the draw site whether your tests run on weekends.

What if my doctor hasn't called me yet? Check the patient portal first. If a routine test is past the window the lab quoted, call the ordering office.

If you are starting testosterone therapy and want the basics of what those labs are for, see TRT 101.