Most healthy adults age 17 or older who weigh at least 110 pounds are eligible to give blood. Beyond those basics, eligibility depends on your medical history, medications, recent travel, and how recently you last donated. Here’s a full breakdown of what qualifies you and what might temporarily or permanently disqualify you.
Age and Weight Minimums
You need to be at least 17 years old in most states, though 16-year-olds can donate with parental consent. There is no upper age limit. The minimum weight is 110 pounds, and height-to-weight requirements can vary depending on the type of donation you’re giving, whether that’s whole blood, platelets, plasma, or a double red cell donation.
What They Check Before You Donate
Every time you show up to donate, staff will check a few vital signs on the spot. Your blood pressure must fall between 90/50 and 180/100. Your pulse needs to be regular and between 50 and 100 beats per minute. They’ll also prick your finger to test your iron levels: women need a hemoglobin reading of at least 12.5 g/dL, and men need at least 13.0 g/dL. If your iron is a bit low, you won’t be permanently disqualified, but you’ll be asked to come back another day.
These checks exist to protect you, not just the blood supply. Donating when your iron is too low or your blood pressure is out of range could leave you feeling faint or unwell.
Medications That Affect Eligibility
Most common medications, including those for high blood pressure, cholesterol, thyroid conditions, and birth control, do not disqualify you. The medications that do cause a deferral fall into a few specific categories.
Blood thinners are the most common reason for a medication-related deferral. If you take warfarin, heparin, or newer oral blood thinners like rivaroxaban, you generally cannot donate while on the medication. Some anti-platelet drugs used to prevent stroke or heart attack require a waiting period of 2 to 14 days after your last dose, depending on the specific drug.
Isotretinoin, the active ingredient in severe acne medications, requires a one-month wait after your last dose. Finasteride, used for hair loss or prostate symptoms, and dutasteride require a six-month wait. These deferrals exist because traces of these drugs in donated blood could cause birth defects if the blood were transfused to a pregnant person.
Tattoos and Piercings
If you got a tattoo at a state-regulated facility that used sterile needles and single-use ink, you can donate with no waiting period. The same applies to piercings done with single-use, disposable equipment. However, if your tattoo was done in a state that doesn’t regulate tattoo facilities, you’ll need to wait three months. The states (and D.C.) that currently lack tattoo facility regulation are Georgia, Idaho, Maryland, Massachusetts, New Hampshire, New York, Pennsylvania, Utah, and Wyoming.
Piercings done with a reusable gun or any reusable instrument also trigger a three-month deferral. The concern in both cases is hepatitis transmission.
Travel Restrictions
Travel to areas where malaria is common triggers a waiting period. If you visited a malaria-risk region, you’ll need to wait three months after returning before you can donate. If you previously lived in one of those areas, the wait extends to three years. Anyone who has been diagnosed with and treated for malaria must wait three years after treatment and remain symptom-free during that time.
One major travel restriction that affected millions of potential donors has been lifted. For decades, people who spent time living in parts of Europe during the 1980s and 1990s were banned from donating due to concerns about mad cow disease (variant Creutzfeldt-Jakob disease). After tracking the issue for years and finding that transmission through blood transfusion was essentially nonexistent, the FDA fully lifted that ban in 2022.
Cancer Survivors
Eligibility after cancer depends on the type. If you’ve had a blood cancer like leukemia, lymphoma, or multiple myeloma, or if you’ve had Kaposi sarcoma, you are permanently ineligible to donate blood. For most other cancers, you can donate once you’ve completed treatment, at least 12 months have passed since treatment ended, and you’ve had no signs of recurrence during that time.
Some low-risk cancers have shorter or no waiting periods. Nonmelanoma skin cancers that have been completely removed and healed, as well as carcinoma in situ, don’t require the 12-month wait. Precancerous conditions generally don’t disqualify you at all, as long as they’ve been treated. Rules can vary between donation centers, so calling ahead is worthwhile if you’re unsure about your specific situation.
How Often You Can Donate
For whole blood, the standard waiting period between donations is about 12 weeks (roughly every three months). This interval was extended from the older eight-week standard after research showed that longer gaps between donations help your body maintain healthy iron stores. Platelet and plasma donations don’t deplete red blood cells the way whole blood does, so they can be done more frequently.
Other Common Deferrals
A few other situations can temporarily delay your eligibility:
- Illness: You need to be feeling well on the day of donation. A cold, flu, or active infection means you should wait until symptoms resolve.
- Pregnancy: You cannot donate while pregnant. Most centers require a waiting period after delivery as well.
- Vaccines: Most routine vaccines, including the flu shot, don’t affect eligibility. Some live-virus vaccines may require a short waiting period.
Eligibility rules are updated periodically as new scientific evidence emerges. If you were turned away in the past, it’s worth checking again, since policies like the European travel ban and several other restrictions have been relaxed in recent years.