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Need Help or want to give your feedback?

Whether you’re having trouble with your account, or would like to make a suggestion, Canadian Blood Services offers you quick and convenient options to troubleshoot or get in touch. Contact us via live chat, consult our FAQ, send an email, or give us a call at 1 888 2 DONATE (1-888-236-6283).

FAQs: Whole Blood Donations

What To Know About Giving Blood

The following are some of the questions we’re asked most often about the blood donation process:

We collect about 450 ml (a pint) of blood during a single blood donation.

The plasma portion of your donation is replaced within hours and the platelet portion within days. Red blood cells can take months to replenish.

You should avoid strenuous activity for six to eight hours after giving blood.

Yes. Please call us if:

  • You decide your blood should not be used.
  • You develop an illness or diarrhea within the next week.
  • You are diagnosed with West Nile Virus within the next 14 days.
  • You test positive for Hepatitis or HIV within the next 12 months.

New donors inquiring:

It can take between 6 to 8 weeks to receive your donor card via Canada Post.

If you have not received your card 8 weeks after your first donation, please do not hesitate to contact us again. You can call us toll free at 1 888 2 DONATE (1-888-236-6283) and a customer service representative will be happy to assist you.

You can still donate blood without your Canadian Blood Services donor card since your donor information is on file. Simply bring a piece of identification with your name and photo, or with your name and signature, to the blood donor clinic.

Obtaining a replacement card

You may reorder your card the next time you donate at your local blood donor clinic. Simply bring a piece of identification with your name and photo, or with your name and signature. If you are a recent donor, simply call us at 1 888 2 DONATE (1 888 236-6283) and we can help you over the phone.

Unfortunately, Canadian Blood Services is unable to issue donor cards to people who no longer donate blood.

People with O negative (O-) blood are considered universal donors because anyone can receive O- blood. But all blood types are needed to meet the needs of patients for blood and blood products.

If you want to know whether a particular medication might keep you from being eligible to donate, you can call us at 1 888 2 DONATE (1-888-236-6283). You can still give blood when taking certain medications: in many cases, it isn’t the medicine but rather the reason for taking it that may be of concern.

The screening process is lengthy and may seem intrusive, but it is absolutely necessary to safeguard the blood supply by screening out people who are at greater risk of transmitting infections through their blood. The criteria we use to determine donor eligibility are based on scientific knowledge of risk factors. All our screening measures meet stringent regulatory requirements and accepted worldwide blood service standards.

While we test every donation using sophisticated and reliable procedures, these tests are not perfect. There are brief periods after infection called ‘window periods’ when current tests cannot detect signs of a virus. Advances in testing technology have reduced but not eliminated these window periods. This is why we have strict screening procedures to ensure each donor poses the least possible risk of transmitting diseases through his or her blood.

Because a lot can happen between donations, we are required to treat every donation as a separate event. For the safety of the blood supply and potential blood recipients, we have to take maximum caution and ask the questions every time.

Current medical information tells us that 17 is the earliest age at which it is safe to give blood. But there are other ways you can help if you want to get involved with Canadian Blood Services before you turn 17. Find out how to become a volunteer or organize a high-school blood clinic by emailing us at or calling 1 888 2 DONATE (1-888-236-6283).

Please plan to have a friend or family member who is not donating with you if you bring children under 10 years of age. Children under 10 and their supervisor are welcome to wait in the refreshment area and enjoy a snack while they wait for their hero/donor. We ask that children in our clinics be supervised by a person who is at least 12 years of age.

Children aged 10 and older are welcome to wait in the refreshment or designated waiting areas without supervision.

Please ensure those joining you are comfortable being in an environment where blood is collected.