Plasma donation centers screen for dozens of factors before every donation, and getting turned away is common. The reasons range from straightforward basics like age and weight to less obvious ones like a recent tattoo, a medication you take, or slightly elevated blood pressure that day. Here’s a breakdown of the most common reasons people get deferred and how long each one lasts.
Basic Eligibility Requirements
You must be at least 18 years old and weigh at least 110 pounds. These are hard cutoffs with no exceptions. The weight minimum exists because smaller bodies have less blood volume, and removing plasma from someone without enough to spare can cause dizziness, fainting, or worse.
You’ll also need valid identification and proof of a current address. If you show up without proper ID, you’ll be turned away regardless of your health status.
Vital Signs Checked at Every Visit
Before each donation, staff will check your blood pressure, pulse, and temperature. These checks can disqualify you even if you were fine last time. Your systolic (top number) blood pressure must fall between 90 and 180, and your diastolic (bottom number) must be between 50 and 100. Your pulse needs to be regular and between 50 and 100 beats per minute.
This means something as simple as rushing to the center, drinking too much caffeine, or feeling anxious can temporarily push your numbers out of range. If you’ve been deferred for vitals, it doesn’t necessarily mean anything is wrong. Try arriving early, sitting quietly for a few minutes, and staying hydrated. You can usually try again the next day.
Medications That Require a Wait
Many common medications trigger a deferral, not because they’re dangerous to you during donation, but because traces of them in your plasma could harm the person who receives it. The wait times vary widely depending on the drug.
- Blood thinners: Most newer blood thinners require a 2-day wait after your last dose. Warfarin and heparin require 7 days.
- Isotretinoin (severe acne medication): 1 month after your last dose.
- Finasteride (for hair loss or prostate symptoms): 6 months.
- Dutasteride (for prostate symptoms): 6 months.
- Some arthritis medications: Anywhere from 1 month to 2 years depending on the specific drug.
- Some psoriasis medications: Up to 3 years.
- Injectable HIV prevention (PrEP): 2 years after your last injection.
- Any experimental or clinical trial medication: 12 months.
- HIV treatment medications: Permanent deferral.
If you take a daily medication and aren’t sure whether it affects eligibility, call the donation center before you go. Many everyday drugs like antidepressants, birth control, and common blood pressure medications are perfectly fine.
Infections That Permanently Disqualify You
Testing positive for HIV, hepatitis B, or hepatitis C results in a permanent ban from donating plasma. Your name goes into a national database called the National Donor Deferral Registry, which is shared across participating plasma centers in the U.S. and Canada. This means you can’t simply try a different location.
Ebola virus infection is also a permanent disqualifier. These permanent deferrals exist because even with advanced screening, the risk of transmitting these infections through plasma products is too high to accept.
Pregnancy and Postpartum
You cannot donate plasma while pregnant. After delivery, you need to wait at least six weeks for your blood volume and protein levels to recover. If you’re breastfeeding after that six-week mark, you can still donate as long as you meet all the other standard eligibility criteria.
Tattoos and Piercings
A new tattoo doesn’t automatically disqualify you, but it depends on where you got it. If the tattoo was done at a state-regulated facility using sterile, single-use needles and fresh ink, most states allow you to donate right away. If you got it in a state that doesn’t regulate tattoo parlors, you’ll need to wait three months.
The same logic applies to piercings. If disposable, single-use equipment was used for both the piercing instrument and the jewelry cassette, you’re fine. If a reusable piercing gun was involved, or if there’s any uncertainty about the equipment, that’s a three-month deferral.
Travel to Certain Regions
Spending time in areas with high rates of malaria or certain other infectious diseases can trigger a waiting period. During your screening, you’ll be asked detailed questions about where you traveled, how long you stayed, whether you left urban or resort areas, and what transportation you used. The specific wait times depend on the country and the length of your visit.
Zika virus infection and diagnosis also affect eligibility, though the specific rules update periodically as outbreaks change. If you’ve traveled internationally in the past three years, be prepared to answer questions about it.
The FDA’s Individual Risk Assessment
The FDA has moved away from blanket demographic deferrals and now recommends that donation centers use individual risk-based screening questions. This means the questionnaire focuses on specific behaviors rather than broad categories. You’ll be asked about recent sexual partners, needle use, and other individual risk factors for HIV and other bloodborne infections. This approach replaced older policies that deferred entire groups of people regardless of their actual risk level.
The screening questionnaire can feel invasive, but every question maps to a specific infection risk. Answering honestly is critical because plasma products are used to treat people with immune deficiencies, bleeding disorders, and other serious conditions. A false answer that lets contaminated plasma through can have life-threatening consequences for the recipient.
Temporary vs. Permanent Deferrals
Most deferrals are temporary. Low iron that day, a cold, a recent vaccination, an out-of-range blood pressure reading: these all resolve on their own. If you were turned away and aren’t sure why, ask the staff directly. They’re required to tell you the reason, and in many cases they can tell you exactly when you’ll be eligible again.
Permanent deferrals are reserved for confirmed positive tests for HIV, hepatitis B, or hepatitis C, a history of Ebola, or ongoing use of HIV treatment medications. Almost everything else has a defined waiting period, and you’re welcome to return once it passes.