Most healthy adults age 17 or older who weigh at least 110 pounds are eligible to donate blood. That covers a large portion of the population, yet only about 3% of eligible Americans donate in any given year. If you meet the basic requirements and feel well on the day of your appointment, you’re likely a good candidate.
Basic Eligibility Requirements
The core criteria are straightforward. You need to be at least 17 years old (16 with parental consent in many states), weigh 110 pounds or more, and be in generally good health. At your appointment, staff will check your blood pressure, temperature, and pulse to confirm you’re fit to donate that day. Your hemoglobin level will also be tested with a quick finger prick: women need a minimum of 12.5 g/dL, and men need at least 13.0 g/dL.
There’s no upper age limit for blood donation. If you’re 70 or 80 and meet the health requirements, you’re welcome to give.
How Often You Can Donate
The waiting period depends on what you’re donating. Whole blood, the most common type, requires a 56-day gap between donations, which means you can give up to six times per year. Platelet donations recover much faster, so you can donate platelets every 7 days, up to 24 times a year. Plasma donors wait 28 days between appointments, allowing up to 13 donations annually. Double red cell donations, which collect twice the red blood cells in a single visit, require 112 days between sessions, or roughly three times per year.
Conditions That Temporarily Disqualify You
A temporary deferral means you can’t donate right now, but the door isn’t closed. Common reasons include taking antibiotics for an active infection, having a cold or flu on the day of your visit, or recently getting a tattoo or piercing (policies vary by state and blood center).
Travel to regions where malaria is common triggers a three-month waiting period after you return. If you previously lived in a malaria-endemic area, the deferral extends to three years. A malaria diagnosis means you’ll need to wait three years after completing treatment and remaining symptom-free.
Pregnancy also temporarily defers donors. Most blood centers ask that you wait six weeks after delivery before donating.
Medications That Affect Eligibility
Many common medications are perfectly fine for blood donors. Aspirin, cholesterol drugs, blood pressure pills, and birth control don’t disqualify you. The medications that do matter generally fall into a few categories.
- Blood thinners: Most require a 2- to 7-day waiting period after your last dose, depending on the specific drug. Warfarin requires 7 days.
- Anti-platelet medications used to prevent stroke or heart attack carry wait times ranging from 2 to 30 days.
- Acne treatments containing isotretinoin (commonly known by the former brand name Accutane) require a 1-month deferral.
- Hair loss or prostate medications containing finasteride or dutasteride carry a 6-month wait.
- HIV prevention drugs (PrEP or PEP) taken by mouth defer donors for 3 months after the last dose; injectable forms require a 2-year wait.
- HIV treatment medications are a permanent deferral.
If you’re unsure about a specific medication, the American Red Cross maintains a detailed deferral list you can check before scheduling.
Who Cannot Donate
Some conditions result in a permanent or indefinite deferral. People currently being treated for HIV are not eligible. Those diagnosed with hepatitis B or hepatitis C after age 11 are typically deferred. Certain cancers and their treatments may also disqualify you, though policies differ by blood center and by how long you’ve been in remission.
People with hemophilia or other bleeding disorders generally cannot donate whole blood because of the risks to their own health. If you’ve ever tested positive for certain infections that can be transmitted through blood, such as Chagas disease or human T-cell lymphotropic virus, you’ll be permanently deferred.
Health Benefits for Donors
Donating blood isn’t purely altruistic. Every visit includes a mini health screening that checks your vital signs and tests for infectious diseases you might not know you carry. This process occasionally catches conditions like high blood pressure or irregular heart rhythms that prompt donors to follow up with their own doctor.
Regular donation is also linked to lower blood pressure and reduced risk of heart attacks. When hemoglobin runs high, donating helps lower blood viscosity, which reduces the likelihood of clot formation, heart attacks, and stroke. For people with hereditary hemochromatosis, a condition that causes dangerous iron buildup, regular blood removal is actually part of the medical treatment.
The screening will also reveal if you have a rare blood type, which is useful information both for you and for patients who depend on hard-to-find blood products.
Preparing for Your Donation
What you eat in the days before donating matters more than most people realize. Iron is the key nutrient, because your body uses it to rebuild the red blood cells you’ve given away. Focus on iron-rich foods like red meat, spinach, beans, and fortified cereals, paired with vitamin C sources like citrus fruits or bell peppers that help your body absorb iron more efficiently. Avoid calcium-heavy foods and drinks like milk or cheese close to your iron-rich meals, since calcium can block iron absorption.
The Red Cross recommends that frequent donors and younger donors consider taking a multivitamin with 18 mg of iron, or an iron supplement with 18 to 38 mg of elemental iron. Teenage donors are especially prone to becoming iron deficient after giving blood, so supplementation is particularly important for this group. After a whole blood donation, continuing an iron supplement for at least 60 days helps replenish your stores. After a double red cell donation, that window extends to 120 days.
On the day of your appointment, drink plenty of water, eat a solid meal, and wear a shirt with sleeves you can roll up past your elbow. The entire process, from check-in to snack table, typically takes about an hour, with the actual blood draw lasting only 8 to 10 minutes.