Plasma donation centers screen for dozens of factors before accepting a donor, and being turned away doesn’t necessarily mean something is wrong with your health. The most common reasons people can’t donate include not meeting basic physical requirements, taking certain medications, having specific infections, or recently getting a tattoo or traveling abroad. Here’s a breakdown of what might be behind your deferral.
Basic Requirements You Might Not Meet
You must be at least 18 years old and weigh at least 110 pounds to donate plasma in the United States. These aren’t flexible. The weight minimum exists because smaller bodies have less total blood volume, and removing plasma from someone without enough to spare raises the risk of dizziness, fainting, or worse.
Before each donation, the center also checks your iron levels through a quick finger prick. Women need a hemoglobin level of at least 125 g/L, and men need at least 135 g/L. If your iron is too low, your body can’t afford to lose the red blood cells that come along with the plasma collection process. This is one of the most common reasons for same-day deferrals, and it can happen even if you felt fine walking in. Eating iron-rich foods like red meat, spinach, or fortified cereals in the days before your appointment can help.
Medications That Disqualify You
Certain medications don’t just affect your health. They stay in your blood at levels that could harm a recipient, particularly a pregnant woman whose baby could be exposed through a transfusion. The deferral periods vary by drug:
- Isotretinoin (Accutane and its generics): 1 month after your last dose. This acne medication causes birth defects and lingers in donated blood.
- Finasteride or dutasteride (Propecia, Proscar, Avodart): 6 months. These hair loss and prostate medications also carry birth defect risks.
- Blood thinners like warfarin, rivaroxaban, or apixaban: 7 days for most. These medications interfere with clotting, which means you could bleed excessively at the needle site, and the plasma itself may not function properly for the recipient.
If you take a blood thinner for a short-term condition, the deferral is temporary. If you’re on one indefinitely for a heart condition or clotting disorder, you’re likely permanently ineligible for plasma donation.
Infections and Bloodborne Diseases
Every plasma donation is tested for a long list of infections, but centers also screen you beforehand to avoid collecting units that will just be discarded. The infections that trigger a deferral include HIV, hepatitis B, hepatitis C, syphilis, West Nile virus, Chagas disease, and several others. Some of these result in permanent disqualification, while others allow you to donate once you’ve been treated and cleared.
If you’ve ever tested positive for HIV or hepatitis C, most centers will permanently defer you. A past hepatitis B infection may also be disqualifying depending on your current status. These policies exist because some infections can persist at undetectable levels and still pose a risk to recipients who may have weakened immune systems.
Tattoos and Piercings
A recent tattoo doesn’t automatically disqualify you. If you got it at a state-regulated shop using sterile, single-use needles and fresh ink, you can donate in most states with no waiting period. But if your state doesn’t regulate tattoo facilities, you’ll need to wait three months.
The same logic applies to piercings. If the equipment was disposable and single-use, you’re fine. If a reusable piercing gun was involved, or if there’s any doubt about sterilization, the wait is three months. The concern in both cases is the small risk of bloodborne infections that may not show up on tests right away.
Travel to Certain Regions
If you’ve recently traveled to a country where malaria is common, you’ll face a deferral. The current guidelines from the FDA set a three-month wait after returning from a malaria-risk area. If you previously lived in one of these regions rather than just visiting, the wait extends to three years. And if you were actually diagnosed with malaria, you can’t donate for three years after treatment, provided you’ve had no recurring symptoms.
One restriction that has been lifted: the old deferral for people who spent time in the United Kingdom, Ireland, or France between 1980 and 2001. That rule was designed to prevent the theoretical transmission of mad cow disease (vCJD) through blood products. The FDA eliminated it in stages between 2020 and 2022, so if that was the reason you were previously turned away, you’re now eligible.
Pregnancy and Recent Childbirth
You cannot donate plasma while pregnant. After giving birth, the standard deferral is six weeks. This protects the donor, whose body is still recovering blood volume and nutrient stores.
There’s also a less well-known issue for women who have been pregnant at any point. Pregnancy can trigger the development of certain antibodies (called HLA antibodies) that, when present in donated plasma, can cause a serious lung reaction in transfusion recipients. Some plasma centers screen women with a history of pregnancy for these antibodies, and a positive result may limit the types of blood products your plasma can be used for, or disqualify you from donating plasma altogether while still allowing whole blood donation.
Autoimmune and Chronic Conditions
Autoimmune diseases like lupus, rheumatoid arthritis, or multiple sclerosis don’t always result in permanent disqualification, but many do in practice. The determining factors are whether the condition has damaged your heart, lungs, or kidneys, and what medications you take to manage it.
If you’re on a stable, low dose of a single medication like methotrexate or hydroxychloroquine and your dose hasn’t changed in six months, some centers will accept you. But if you’re on higher doses, multiple immunosuppressants, or if your condition has caused organ damage, you’ll typically be deferred. The concern is twofold: protecting you from the physical stress of donation, and ensuring the plasma itself is safe for recipients.
Heart conditions, uncontrolled diabetes, and bleeding disorders also commonly lead to permanent deferral. If you have a chronic condition and aren’t sure whether it disqualifies you, calling the donation center before your appointment saves you a wasted trip.
Temporary Deferrals You Can Wait Out
Many deferrals aren’t permanent. If you were turned away for low iron, a recent tattoo, travel, a new medication, or a minor illness, you can come back once the waiting period passes. Centers typically tell you exactly how long to wait at the time of your deferral. Common temporary deferrals include:
- Cold or flu: Wait until symptoms resolve completely.
- Antibiotics: Typically wait until the course is finished and you’re feeling well.
- Vaccines: Some vaccines require a short deferral period, usually a few days to a few weeks depending on the type.
- Low hemoglobin: You can try again at your next eligible donation date, often after improving your diet or taking iron supplements.
If you were deferred but weren’t given a clear explanation, ask the center staff directly. They’re required to tell you the reason, and in many cases, it’s something fixable.