Here you will find answers to the most common questions related to blood donation, the Stem Cell Registry and the Blood Service.

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Blood donation

Are the iron supplements given to blood donors suitable for vegans?

Yes they are. The Ferrodan iron supplement given to blood donors does not contain iron or any other ingredients of animal origin. This sugar-, gluten- and lactose-free supplement is suitable for people with lactose-intolerance and celiac disease, and for vegans. The Ferrodan product is a Finnish dietary supplement that contains vitamin C, to improve its absorption, in addition to iron (ferrous fumarate).

Blood donation

Can I give blood if I'm trying to get pregnant?

Women attempting to become pregnant are advised to avoid blood donation, since they should keep up a good haemoglobin level. However, donating blood once in early pregnancy does not constitute a risk, and blood donation does not increase the risk of miscarriage.

Blood donation

Exercise and sport

Exercising or doing sport does not prevent blood donation, but there are a couple of things to consider regarding exercise as you plan the timing of your donation.

During blood donation approximately half a litre of blood is lost and this will affect your fluid balance for a short while.

On the other hand, the decrease in hemoglobin levels will affect your performance in strenuous exercise and physical endurance, both short and long term. You can do normal exercise the day after your donation. Returning to strenuous exercise or goal-directed personal best performance may, however, take around one month from blood donation.

To ensure the proper recovery of your fluid balance you cannot do strenuous exercise or sport that causes sweating or requires straining of the donation arm on the day of your donation. To make sure that your fluid balance is as optimal as possible, do not come to donate straight after very strenuous exercise.

Would you like more information? Please call the free information number for blood donors on 0800 0 5801 (Mon to Fri from 8:00 a.m. to 5:00 p.m.).

Blood donation

How often can you donate blood?

Young women between 18-25 years are recommended to donate blood only max. once a year, all other women max. 2-3 times per year and men max. 3-4 times per year.

The minimum interval between blood donations is 91 days for women and 61 days for men.

You can check your minimum interval date with the donation date calculator.

With regard to the donation of platelets, the donation interval is shorter because the red cells are returned to the donor’s circulation.  ​

Blood donation

How quickly is donated blood replaced?

Blood volume will be replaced within a few hours and can be speeded up by drinking adequately on the day of the donation.

The red cell count will be the same in approximately three months. Red cells live for approximately 120 days or four months and regenerate constantly, regardless of blood donation.

Blood iron concentration recovers in approximately a couple of months.​ It’s important that blood donors get enough iron from their diet to replace the iron loss.

To prevent iron deficiency donors must have minimum intervals between donations, and donors in high risk are provided iron supplementation.

Blood donation

I'm a woman aged between 18 and 25. Can I only donate blood once a year?

For women aged 18 to 25, we recommend only one donation per year. This is because blood donor studies have shown that young women have a particularly high risk of developing iron deficiency.

During a single donation, women lose as much as 60–100% of the iron contained in their iron reserves. The reserves are replenished slowly, and the purpose of this recommendation is to promote the replenishment of donors’ iron reserves.


Blood donation

Is blood donation safe?

Blood donation is safe and rarely causes any harm for a healthy person. The health questionnaire and interview aim to confirm that the donation is safe for the donor. The Blood Service is responsible for the donation being safe both for the donor and patient.

Blood donation may sometimes be related to some temporary symptoms or discomforts, mainly nausea or bruises. All blood donors are insured against adverse effects or accidents caused by blood donation.

Because needles and other equipment used for the blood collection are always disposable, you cannot be infected via blood donation.

The most important thing for the patient receiving the blood is that the blood donor is healthy. Because only a small portion of pathogens can be tested, the careful selection of donors is crucial for the safety of the patient. In addition to the measurement of haemoglobin and the determination of blood group, the blood samples taken in connection with donation are tested for the most important blood-borne infections (HIV, hepatitis A, B and C, syphilis).

However, if the donor has been infected very recently, this may not be visible in the laboratory tests and causes a small risk to the patient’s safety. The purpose of different-length waiting periods before donation is to prevent donation during this window period. However, the microbe safety of products can never be perfect.​

Blood donation

Pregnancy and birth

You cannot donate blood if you are pregnant. After giving birth, you must wait at least six months before donating blood.

Donating blood once in early pregnancy does not constitute a risk, and blood donation does not increase the risk of miscarriage. However, women attempting to become pregnant are advised to avoid blood donation, since those hoping to become pregnant should keep up a good haemoglobin level.

Would you like more information? Please call the free information number for blood donors on 0800 0 5801 (Mon to Fri from 8:00 a.m. to 5:00 p.m.).

Blood donation

Why does the Blood Service measure donors’ haemoglobin levels but not the iron reserves, such as ferritin?

Measuring the haemoglobin levels of potential blood donors is a regulatory requirement. The measurement ensures that the donor does not have anaemia, or in other words that their haemoglobin concentration is not too low. People can donate blood if their blood haemoglobin concentration is 125–175 g/l for women and 135–195 g/l for men. Donating blood lowers the haemoglobin concentration temporarily by 10–15 g/l.

Blood donors lose iron while donating blood. Iron deficiency occurs most in the youngest female donors (18–25-year-olds). For this group, we recommend donating blood no more than once a year. For other women, we recommend a maximum of 2–3 donations a year and for men a maximum of 3–4 donations a year. Donation interval, rather than a factor such as the donor’s age or diet, is the strongest single indicator of iron levels.

The Blood Service does not have exact requirements or recommendations concerning ferritin levels for potential blood donors who have had their ferritin levels measured independently. In terms of blood donation, the interpretation of ferritin levels depends on why the ferritin levels and iron stores have been investigated. If the levels have been measured for diagnostic purposes and low ferritin levels have been measured, the individual in question may not donate blood. On the other hand, an incidental finding of low ferritin levels in an asymptomatic person is not, in itself, an obstacle to donation. At the Blood Service, the prevention of harmful iron deficiency is based on the different recommended donation intervals for women and men (see above) and the minimum donation intervals (at least 91 days for women and at least 61 days for men), as well as on the administration of iron supplements to blood donors in the risk group (women under the age of 50 as well as all frequent donors).

Blood donors must feel well; you may not donate blood if you feel exhausted or exceptionally tired. Diagnosed iron deficiency anaemia or other symptomatic condition associated with iron deficiency should be treated. You may donate blood when your condition has improved and you have been treated for iron deficiency at least for six months.

Blood donation

Why must a donor weigh at least 50 kilos?

The minimum weight requirement is based on blood volyme.

The human body contains approximately five litres of blood. For safety reasons, the blood extracted for a donation, which totals around half a litre, may not exceed 10% of the total blood in the body.

The amount of blood in the body depends on your body weight, and for those weighing under 50 kg it is so small that donating increases the risk of post-donation complications such as faintness, nausea or dizziness.

The same weight limit is given in many international recommendations and is mentioned in the European Blood Directive, with which all Member States must comply.​