Your sampling instructions | IMULAB
Sampling instructions

Thank you. Now let's get the sample right.

Your results are only as good as the sample they come from. Below you will find how each collection method works, what to expect on the day, and the preparation steps that apply to the test you have ordered.

Start here

How is your sample being taken?

Your confirmation email and the product page tell you which methods your test allows. Choose yours and everything below adapts to it.

Why some tests cannot be done by finger prick
A fingertip yields a small volume, and that blood is a mix of capillary, arterial and venous blood along with a little tissue fluid. That is fine for many markers, but larger panels need more serum than a fingertip provides, and some markers are only validated on a venous sample. Squeezing the finger to force more blood out makes it worse, because it dilutes the sample with tissue fluid and can rupture red cells, which raises potassium and makes the sample unusable.
Nearly there

Find your instructions

Some tests need fasting, some need an early morning sample, and some need timing to your cycle. Tell us what you ordered and we will show you only what applies.

Who is the test for?
Which test did you order?
If you ordered more than one, work through them one at a time.
Nothing listed

We do not have a finger prick test listed here yet. If your order confirmation offers finger prick collection, email support@imulab.co and we will send your instructions across.

Where is your sample being taken?
Only the options available for your test are shown. This changes how the sample gets to the laboratory.
Where are you in your cycle?
This test measures hormones that change across the cycle, so the day you sample changes how your results are read.
Anything you are taking?
Tap all that apply. Do not stop anything, we just need to know.

Your instructions

Answer the questions above
Choose your test and we will build your instructions here.
The night before

Quick check

    The rest of it

    Things people ask us

    I am unwell, should I still test?

    No, wait until you have recovered. Do not sample with a fever or an active infection, and leave around two weeks after a significant illness.

    CRP rises within hours of an infection starting. Ferritin rises behind it and stays elevated for weeks, while serum iron falls. A sample taken in that window describes the infection rather than your baseline. The same applies in the fortnight after surgery, a vaccination, or a course of antibiotics.

    A mild head cold with no fever is usually fine. Record it when you register your sample.

    Does creatine affect my results?

    It affects one marker, and it is worth understanding before you see the number.

    Creatine is metabolised to creatinine, so supplementing raises serum creatinine. Because eGFR is calculated from creatinine, eGFR then falls. That reads as reduced kidney function when kidney function is normal, there is simply more creatinine in circulation.

    Keep taking it. Record the dose and whether you are loading.

    Do I need to stop my prescribed medication?

    No. Statins, blood pressure medication, contraception, antidepressants, thyroid medication and steroids should all be taken exactly as prescribed.

    Only your prescriber should change a prescription, and never for the purpose of a blood test. List everything when you register your sample so the reviewing doctor knows what they are reading.

    The one timing point worth following is thyroid medication, which should be taken after the sample rather than before.

    What about my other supplements?
    • Vitamin D, omega 3, magnesium, protein and collagen: continue as normal
    • Biotin: pause where your instructions say so
    • Iron: leave 24 hours after your last dose
    • Anything started in the last month: record it, as it may not be reflected in your bloods yet

    If you are testing to find out whether a supplement is working, do not stop it. Stopping is the one thing that makes the result uninterpretable.

    Does a finger prick hurt, and what if I struggle to fill the tube?

    It is a brief sharp scratch and most people find it easier than expected. The side of the fingertip has fewer nerve endings than the pad, which is why we ask you to use it.

    If the blood is not flowing, the cause is almost always temperature. Stop, run your hands under hot water for a minute, dry them, swing your arm below waist height, and start again with a fresh lancet on a different finger. Do not squeeze hard. Squeezing forces tissue fluid into the sample and can rupture red cells, which makes the sample unusable.

    If you cannot fill it, do not send a part filled tube. Email us and we will send a replacement kit at no cost.

    When will I get my results?

    Some results are back within 2 working days of your sample reaching the laboratory, but it varies by test, so allow 2 to 4 working days.

    When your results are ready you will receive an email, and you can log in to view them online.

    Where this guidance comes from
    1. Nordestgaard BG, Langsted A, Mora S, et al. Fasting is not routinely required for determination of a lipid profile: a joint consensus statement from the European Atherosclerosis Society and the European Federation of Clinical Chemistry and Laboratory Medicine. Eur Heart J. 2016;37(25):1944 to 1958.
    2. Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715 to 1744.
    3. Brambilla DJ, Matsumoto AM, Araujo AB, McKinlay JB. The effect of diurnal variation on clinical measurement of serum testosterone and other sex hormone levels in men. J Clin Endocrinol Metab. 2009;94(3):907 to 913.
    4. Pettersson J, Hindorf U, Persson P, et al. Muscular exercise can cause highly pathological liver function tests in healthy men. Br J Clin Pharmacol. 2008;65(2):253 to 259.
    5. Thomas L. Effect of physical exercise on laboratory test results. Clinical Laboratory Diagnostics, chapter 51.
    6. Kratz A, Lewandrowski KB, Siegel AJ, et al. Effect of marathon running on hematologic and biochemical laboratory parameters. Am J Clin Pathol. 2002;118(6):856 to 863.
    7. Avery G. Biotin interference in immunoassay: a review for the laboratory scientist. Ann Clin Biochem. 2019;56(4):424 to 430.
    8. Piketty ML, Prie D, Sedel F, et al. High dose biotin therapy leading to false biochemical endocrine profiles. Clin Chem Lab Med. 2017;55(6):817 to 825.
    9. World Health Organization. Guideline on the prevention, diagnosis and treatment of infertility, 2025. Day 2 to 3 FSH, AMH and antral follicle count for ovarian reserve.
    10. Namaste SM, Rohner F, Huang J, et al. Adjusting ferritin concentrations for inflammation: BRINDA project. Am J Clin Nutr. 2017;106(Suppl 1):359S to 371S.
    11. Ain KB, Pucino F, Shiver TM, Banks SM. Thyroid hormone levels affected by time of blood sampling in thyroxine treated patients. Thyroid. 1993;3(2):81 to 85.
    12. Post A, Tsikas D, Bakker SJL. Creatine is a conditionally essential nutrient: effects of supplementation on serum creatinine and estimated GFR. Nutrients. 2019;11(5):1044.
    13. Herbert J, Bilezikian J, Silverberg SJ. Effect of ejaculation on serum prostate specific antigen concentration. Urology. 1996;47(4):511 to 516.
    14. Wiegratz I, Kutschera E, Lee JH, et al. Effect of four oral contraceptives on thyroid hormones, adrenal and blood pressure parameters, and sex hormone binding globulin. Contraception. 2003;67(5):361 to 366.
    Any questions

    Ask us rather than guess

    If something here does not fit your situation, if you are unsure whether to sample this week, or if anything in your kit is missing, email us before you take the sample.

    support@imulab.co

    Know. Act. Become.

    This page explains how to collect a sample that reflects your usual physiology. It is general guidance, not medical advice, and it does not replace the advice of your doctor. Never stop or change a prescribed medication in order to take a blood test. If you feel unwell, speak to your GP or call 111.