Wellness·4 min read

How Often Can You Donate Blood — And Other Things to Know Before Your Appointment

Woman Donating Blood
Design: theSkimm | Photo: iStock
June 10, 2022

Donating blood is a way to give back to the community and help those in need. But there are some important things to know before you make your appointment. From how often you can donate blood, to who’s eligible, what to eat beforehand, and beyond, we have the answers to your blood donation FAQs.

How often can I donate blood?

The answer varies based on how you plan to donate. Because yes, there are different ways to donate blood — you can opt for “whole blood” donation or focus on giving specific components of your blood (like plasma, platelets and red blood cells). In terms of how often, you can donate:

Note: These are general guidelines. But how often you can donate may vary based on red cell and plasma loss limit guidelines. Ask your medical provider about your red cell and plasma levels before donating to make sure you stay healthy.

Do I need to meet certain qualifications to donate blood?

Yes. There are rules in place to keep you (and those receiving the blood) safe and healthy. 

You’re eligible to donate blood if…

  • You’re at least 17 years old.

  • You weigh at least 110 pounds.

  • You meet the minimum hemoglobin level (read: the amount of protein in your red blood cells that carry oxygen) for blood donation (at least 12.5 g/dL for women and 13.0 g/dL for men). 

  • It’s been at least 24 hours since you underwent a dental procedure — and don’t have any signs of infection. (P.S. If you do have an infection, you’ll have to wait to donate until you finish your antibiotics. And you’d have to wait three days to donate after having oral surgery.)

You may not be eligible to donate blood if…

  • You’re currently (or were recently) sick.

  • You’ve gotten a tattoo or piercing in the last three months.

  • In the past three years, you’ve traveled to areas where you can be exposed to mosquito-borne infections like malaria (think: parts of Africa and South America).

  • You’re on certain medications. Most of them won’t make you ineligible to donate blood (think: birth control). But a few meds will require a waiting period before you can donate. Including PrEP medications like Truvada (waiting period: three months since your last dose), Accutane (one month since the last dose), and Aubagio (wait two years after the last dose), among others

  • You have certain medical conditions. Like cancer (depending on the type and your treatment history), tuberculosis (ineligible to donate) or if you’ve been exposed to hepatitis (waiting period: 12 months from your last exposure). Here’s the full list

How should I prepare to donate blood?

During the 24 hours leading up to your appointment…

  • Get a full night’s sleep.

  • Avoid fatty foods. Instead, go for iron-rich foods to increase the iron levels in your body. 

  • Skip the aspirin. Particularly if you’re donating blood platelets, you’ll need to stop taking aspirin at least 48 hours before your appointment. Because the drug affects your platelets’ ability to function properly.

  • Drink plenty of fluids.

How long does it take to donate blood?

Red Cross says the entire appointment should only take about an hour. And that the actual drawing of the blood — usually a pint — takes about eight to 10 minutes. But the amount of time it takes to draw blood can also depend on factors like your medical history.

But if you decide to do an apheresis donation (aka filtering out specific components of the blood to donate, like platelets or plasma) then your appointment could take up to two hours. During this process, you’ll be hooked up to a machine that filters out the specific component in your blood that’s needed. And then returns the unused portions that aren’t needed back to you. 

What should I do after donating blood?

Rest. And be alert if you start to feel unwell. Some tips: 

  • After donating, you’ll be asked to sit in an observation area to make sure you’re well. After 15 minutes, you can leave. 

  • If you feel lightheaded, lie down until the feeling passes.

  • Keep your bandage on and dry for five hours after donation.

  • If you bleed after taking off the bandage, apply pressure on the area until the bleeding stops.

  • Avoid intense physical activity for up to two days. 

  • Drink extra fluids and plan to eat iron-rich foods like beef and spinach. 

  • If you forgot to report any health information, test positive for COVID, or experience signs of sickness (think: fever) within 48 hours after donating, contact your doctor and the blood donation center to let them know ASAP.


Preparation is key when it comes to donating blood. So don’t forget to keep track of when you last donated and when you’ll be eligible to donate again. Prep appropriately ahead of your appointment to keep yourself safe. And be sure to finish your cookies and juice.

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