Several categories of medication can make you temporarily or permanently ineligible to donate plasma. The most common ones are blood thinners, acne and psoriasis drugs that cause birth defects, certain hair loss medications, and HIV prevention drugs. Most medications don’t disqualify you outright but require a waiting period after your last dose. The specific rules vary somewhat between donation centers, so the deferral time you’re told at one location may differ slightly from another.
Blood Thinners (Anticoagulants)
Blood thinners are one of the most frequently encountered medication deferrals. These drugs alter how your plasma clots, which is a problem because plasma is collected specifically for its clotting factors and proteins. Donating while on a blood thinner could also cause you excessive bruising or bleeding at the needle site.
The American Red Cross lists the following deferral periods after your last dose:
- Warfarin (Coumadin, Jantoven): 7 days
- Apixaban (Eliquis): 2 days
- Rivaroxaban (Xarelto): 2 days
- Dabigatran (Pradaxa): 2 days
- Edoxaban (Savaysa): 2 days
- Enoxaparin (Lovenox): 2 days
- Dalteparin (Fragmin): 2 days
- Fondaparinux (Arixtra): 2 days
- Heparin: 2 days
Some centers use longer windows. Mayo Clinic’s deferral list, for example, requires a 7-day wait for all anticoagulants, including the newer ones like Eliquis and Xarelto that the Red Cross defers for only 2 days. If you take a blood thinner daily for an ongoing condition like atrial fibrillation or a clotting disorder, you’re effectively ineligible because you’ll never clear the waiting period. People who took a short course after surgery, on the other hand, can typically donate once they’ve been off the medication long enough.
Antiplatelet Medications
Antiplatelet drugs work differently from anticoagulants but also interfere with clotting. Aspirin alone generally does not defer you from donating plasma (though it does defer platelet donation). However, stronger antiplatelet medications like clopidogrel (Plavix) and prasugrel (Effient) typically require a 14-day deferral after the last dose. Ticagrelor (Brilinta) carries a similar wait. If you take one of these daily after a stent placement or heart attack, you’ll likely remain ineligible for the duration of your treatment.
Medications That Cause Birth Defects
Certain drugs are so harmful to a developing fetus that even trace amounts in donated plasma pose a risk. These carry some of the longest deferral periods of any medication category.
Isotretinoin (Accutane, Absorica, Claravis), used for severe acne, requires a 1-month deferral after your last dose. This is relatively short because the drug clears from your body within weeks. Acitretin (Soriatane), a psoriasis medication, is a different story: it requires a 3-year wait. Acitretin converts into a compound that can linger in your body for years, especially if you consume alcohol during or after treatment. Etretinate (Tegison), an older psoriasis drug no longer sold in the U.S., results in permanent deferral because it can remain stored in fat tissue indefinitely.
Dutasteride (Avodart), used for enlarged prostate, requires a 6-month deferral. Finasteride (Proscar, Propecia), used for both prostate enlargement and hair loss, requires a 1-month wait. Both drugs can cause birth defects in male fetuses, and the concern applies regardless of whether you’re male or female, because donated plasma could go to anyone.
HIV Prevention Drugs (PrEP and PEP)
If you take oral PrEP or PEP to prevent HIV infection, you must wait 3 months after your last dose before donating. For injectable, long-acting versions of these medications (such as cabotegravir, sold as Apretude), the deferral jumps to 2 years. The issue isn’t that these drugs are harmful to recipients. It’s that PrEP and PEP can suppress HIV to undetectable levels in your blood, meaning the screening tests used at donation centers might not catch an active infection. The deferral gives enough time for HIV, if present, to become detectable again.
Antibiotics and Infection-Related Medications
Antibiotics themselves are not usually the disqualifying factor. The infection you’re taking them for is. Most centers require that you finish your full antibiotic course and be symptom-free before donating. The standard wait is typically 24 to 72 hours after your final dose, assuming you feel well and the infection has resolved. If the antibiotics were prescribed for something more serious, like a systemic or blood-borne infection, the deferral will be longer and assessed on a case-by-case basis.
Antifungal medications for minor conditions like athlete’s foot or a yeast infection generally don’t cause a deferral. Systemic antifungals taken for more serious infections may require a waiting period.
Vaccines
Vaccines aren’t medications in the traditional sense, but they come up during every pre-donation screening. The deferral depends on whether the vaccine uses a live or inactivated virus. Inactivated vaccines, including flu shots, tetanus, hepatitis B, and COVID-19 vaccines, typically carry no deferral at all as long as you feel fine. Live vaccines, such as MMR (measles, mumps, rubella), chickenpox, yellow fever, and the nasal-spray flu vaccine, usually require a 4-week wait. The smallpox vaccine requires an 8-week deferral, or longer if the vaccination site hasn’t fully healed.
Medications That Permanently Disqualify You
A few medications result in a lifetime ban from plasma donation. The most significant is human pituitary-derived growth hormone. Before 1985, growth hormone treatment for children was extracted from the pituitary glands of cadavers, and some of those preparations were contaminated with prions, the proteins responsible for Creutzfeldt-Jakob disease. Anyone who received this form of growth hormone at any point is permanently ineligible. Modern synthetic growth hormone (somatropin) does not carry this deferral.
Etretinate, as mentioned above, also results in permanent ineligibility. Bovine insulin sourced from cattle in countries with a history of mad cow disease has historically been another permanent disqualifier, though this is increasingly rare as synthetic insulin has become the global standard.
Medications That Usually Don’t Affect Eligibility
Most common daily medications are fine. Blood pressure drugs, cholesterol-lowering statins, thyroid medications, antidepressants (SSRIs and SNRIs), birth control pills, and over-the-counter pain relievers like ibuprofen and acetaminophen do not typically disqualify you. Diabetes medications, including metformin and most injectable insulins, are also generally acceptable as long as your condition is well managed.
The concern with these medications isn’t the drug itself but the underlying condition. If your blood pressure is dangerously high at the time of screening, you’ll be turned away regardless of whether you take medication for it. Similarly, someone with well-controlled diabetes on medication will likely qualify, while someone with uncontrolled diabetes might not.
Why Deferral Times Vary Between Centers
You may notice that the Red Cross, Mayo Clinic, and commercial plasma centers like CSL Plasma or BioLife list slightly different wait times for the same drug. This happens because the FDA sets minimum safety standards, but individual organizations can adopt stricter policies. Commercial plasma centers, which collect source plasma for manufacturing into therapies, sometimes apply different criteria than blood banks collecting plasma through whole blood or apheresis donations. Always check with your specific donation center before your appointment, and bring a list of your current medications, including supplements, so the screening staff can give you a clear answer on the spot.