Please note that sample analysis methods, test codes and instructions may differ depending on the laboratory. Samples for the Puhti tests are taken and analyzed at Mehiläinen laboratories. Always follow the instructions of the laboratory taking the sample.

Why is blood test preparation important?

Blood tests are a central part of health monitoring and disease diagnosis. To ensure your blood test results are as reliable as possible and accurately reflect your true health status, following preparation guidelines is paramount. For example, eating, drinking, medication, or physical exertion can all impact blood values.

General guidelines for blood test preparation

Always follow the personalized instructions you receive. Generally, it’s good to keep the following in mind before sample collection:

• Come healthy: Only get tested if you are healthy. Illness can affect results.
• Avoid alcohol and smoking: Alcohol consumption and smoking should be avoided the day before sample collection. They can alter the body’s hormone and enzyme levels.
• Light meal allowed for non-fasting tests: If the test doesn’t require fasting, you can eat a light meal before sample collection. However, avoid caffeinated drinks like coffee or tea.
• Avoid physical exertion: It’s recommended to avoid strenuous physical exertion during the 24 hours before sample collection. It can change blood plasma volume and metabolism.
• Pause nutritional supplements: It’s recommended to avoid taking nutritional supplements the day before sample collection. They might distort test results.
• Pausing medication: Doctor-prescribed medications can usually be taken normally. Always discuss pausing medication with your attending physician.
• Relax before sample collection: Sit for about 15 minutes before sample collection to allow blood circulation to stabilize.

Which blood tests require fasting?

Most of Puhti’s test packages do not require fasting. You can always see the fasting requirement on the specific test’s order page. If your order includes even one test that requires fasting, please fast before sample collection. For a fasting sample, you must not eat or drink for 8–12 hours. Fasting should not exceed 14 hours.

Fasting tests in Puhti’s selection include:

• Glucose (fP-Gluk)
• Folate (fS-Folaat)
• Transferrin iron saturation (fS-TrFeSat)
• Parathyroid hormone (fP-PTH)
• Transferrin (fS-Transf)
• Iron (fP-Fe)
• Urea (fP-Urea)
• Phosphate (fS-Pi)
• Vitamin B6 (fB-B6-Vit)
• Growth hormone (fS-GH)
• Vitamin A (fS-A-vit)
• Vitamin E (fS-E-Vit)
• Vitamin B1 (fB-B1-Vit)
• Vitamin B2 (fB-B2-Vit)

The following Puhti test packages require fasting:

• Laboratory package for pregnancy planning
• Comprehensive iron deficiency and anemia laboratory package
• Vegetarian and vegan laboratory package
• Iron absorption laboratory package
• Blood sugar and cholesterol laboratory package
• Super laboratory packages
• Lipoprotein laboratory package
• Vitamin laboratory package
• Hair well-being laboratory package

During fasting, you should not drink large amounts of water or soft drinks. Alcohol, coffee, tea, and tobacco can affect sample collection, so it is recommended to avoid them during fasting as well. In the morning before sample collection, you can drink a glass of water and take necessary medications, unless otherwise instructed by a physician.

Why do some blood tests require a specific time of day?

The body’s functions and hormone and compound levels vary throughout the day. Therefore, some blood tests require sample collection at a specific time of day to ensure results are comparable with reference values. You will receive precise instructions via email after ordering or on Puhti’s online store product pages.

Puhti tests requiring a specific time of day:

• Testosterone (free calculated or total): Sample taken between 7 AM and 12 PM. Male levels decrease in the afternoon and evening.
• Cortisol (S-Korsol): Morning sample between 6 AM and 10 AM.
• Iron (fP-Fe): Sample taken between 7 AM and 9 AM.
• Transferrin iron saturation (fS-TrFeSat): Sample taken between 7 AM and 9 AM.
• Prolactin (S-PRL): Sample taken two hours after waking, preferably between 10 AM and 2 PM.
• Anti-Müllerian hormone (AMH): Measurement is usually done in the early part of the natural menstrual cycle. Avoid combined hormonal contraceptives and discuss preparation with a physician. After biotin medication (over 5 mg/day), the sample is taken 8 hours after the dose. The test should not be done during breastfeeding.
• Chlamydia and gonorrhoea from the throat: Morning sample recommended. Avoid eating, drinking, nicotine products, and throat lozenges for about an hour before sample collection.
• Pregnancy test from urine: Morning sample is recommended. Avoid drinking large amounts before sample collection so that the urine does not become diluted.
• TSH: Sample taken before thyroid medication or four hours after taking the medication. The level is most stable between approximately 10 AM and 8 PM.
• Follicle-stimulating hormone FSH: Test taken at the beginning of the natural menstrual cycle (days 3–5 of the cycle). After hormonal contraception, a break of at least 4 weeks is recommended.
• Luteinizing hormone LH: Test taken at the beginning of the natural menstrual cycle (days 3–5 of the cycle). After hormonal contraception, a break of at least 4 weeks is recommended.

The following Puhti test packages require sample collection between 7 AM and 10 AM due to testosterone:

• Men’s comprehensive laboratory package
• Men’s super laboratory package
• Active men’s laboratory package
• Men’s 50+ laboratory package

Iron absorption test – special instructions

An appointment for the iron absorption test must be booked through Mehiläinen’s appointment booking. The sample is taken at Mehiläinen laboratories, excluding Felicitas, Synsam, Mehiläinen’s public health centres, and occupational health units.

Preparation and course of the test:

• Book a sample collection appointment at the laboratory for the morning before 10 AM, when the first sample will be taken.
• Pause iron medication for 3–4 days before the test.
• Medications affecting iron absorption, such as antibiotics (fluoroquinolones, tetracyclines, doxycycline), thyroxine, bisphosphonates, Parkinson’s medications (levodopa/carbidopa), and calcium, should be taken at least three hours before the test or only after the test.
• Do not eat or drink for at least 10 hours before sample collection. In the morning, if necessary, you can drink a glass of water with medications.
• Bring the investigational medicinal product (Spartofer 200 mg).
• The test lasts 2 hours. Two blood samples are taken during this time. After the first, you will receive an iron dose.
• Do not leave the laboratory or consume snacks or coffee during the test, as they affect iron absorption.
• Do not perform the test during an acute illness (e.g., common cold) or inflammatory condition. Inflammation can distort ferritin results.

STHLM3 prostate test sample collection instructions

This test does not require fasting and can be done at any time of day. Additional information is collected during sample collection. Be prepared to answer the following questions at the laboratory:

• Your age
• Have you had a prostate biopsy (where no cancer was found)? When?
• Has a close relative (father, brother, son) had prostate cancer?
• Are you taking medication: alpha-reductase inhibitor (e.g., Finasteride, Gefina, Proscar, Dutasteride, Dutester, Avodart, or Duodart)?

Laboratory test results and their interpretation

You can conveniently access your laboratory test results in the MyJournal service. The results always include reference values, which allow you to initially interpret your own values. If there are deviations in the results or you need help interpreting them, you can easily book a remote physician consultation through Puhti. The physician will help you understand the results and, if necessary, guide you to further examinations.

How do I prepare for a follow-up test?

For follow-up tests, it is important to try to maintain similar conditions in the days leading up to the test. Sleep, eat, drink, exercise, and work as usual. Intense stress, grief, or strenuous athletic performance can affect values and distort follow-up results of blood samples.y drugs for a couple of weeks before testing, as they can distort calprotectin results by giving a false positive.

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