Can You Donate Plasma with Allergies? Seasonal Allergy Guide (2026)

Seasonal Allergies & Plasma Donation

Seasonal allergies — also called hay fever or allergic rhinitis — affect over 80 million Americans each year. If you're a plasma donor who suffers from spring pollen, fall ragweed, or year-round dust and mold allergies, here's the good news: seasonal allergies do NOT disqualify you from donating plasma.

Plasma centers are interested in your overall health and protein levels, not your histamine response to pollen. As long as you meet the standard eligibility criteria (weight, protein levels, vitals), seasonal allergy symptoms will not prevent you from donating.

When seasonal allergies WON'T affect donation:

• Sneezing, runny nose, or nasal congestion from pollen or ragweed
• Itchy or watery eyes
• Post-nasal drip or mild sore throat from allergies
• Mild skin irritation or hives from environmental allergens

When allergies MIGHT affect donation:

• Fever over 99.5°F (could indicate infection, not just allergies)
• Severe respiratory distress or wheezing (asthma flare)
• Active anaphylactic reaction or recent anaphylaxis episode
• Taking an allergy medication that was prescribed for a non-allergy condition

Allergy Medications: Which Are Allowed?

All common over-the-counter allergy medications are accepted at plasma donation centers. Here's a breakdown:

Benadryl (Diphenhydramine) & Drowsiness Concerns

Benadryl is the one allergy medication worth discussing in more detail. While it is fully allowed for plasma donation, it's a first-generation antihistamine that causes significant drowsiness in most people.

Practical considerations with Benadryl:

• Drowsiness during donation: Plasma donation takes 45-90 minutes. If you took Benadryl within 4-6 hours of your appointment, you may feel very sleepy during the procedure. While falling asleep in the donation chair is common (and not dangerous), extreme drowsiness could make it harder to respond if staff need to communicate with you.
• Driving after donation: Combining Benadryl drowsiness with the mild lightheadedness some donors feel after donation could impair your driving. Consider whether you can arrange a ride home.
• Better alternatives: If you need an antihistamine before donating, consider switching to a non-drowsy option like Zyrtec, Claritin, or Allegra. These provide comparable allergy relief without the sedation.

Allergy Shots (Immunotherapy) Timing

Allergy shots (subcutaneous immunotherapy or SCIT) are a different story from oral allergy medications. If you receive regular allergy injections, you need to follow specific timing rules:

• Wait 24 hours after your allergy shot before donating plasma. This is the standard deferral period at most centers.
• Reason: Allergy shots deliberately introduce allergens into your body to build tolerance. In the first 24 hours after an injection, there's a small risk of a delayed allergic reaction. Plasma centers want to ensure you're past this window before drawing your blood.
• Sublingual immunotherapy (SLIT) drops/tablets: These are typically allowed without a waiting period since they carry a much lower risk of systemic reaction. However, confirm with your specific center.

Scheduling tip:

If you get allergy shots weekly, schedule your shot and plasma donation on different days. For example: allergy shot on Monday, plasma donations on Wednesday and Friday. This easily clears the 24-hour window.

Severe Allergic Reactions & Anaphylaxis History

While seasonal allergies won't defer you, a history of severe allergic reactions (anaphylaxis) may require additional screening:

Tips for Donating During Allergy Season

1. Take your allergy medication as normal — don't skip it to "be safe" for donation. All OTC allergy medications are accepted.
2. Hydrate extra — antihistamines like Benadryl and Zyrtec can have a mild dehydrating effect. Drink an extra 8-16 oz of water before your appointment.
3. Bring tissues — sneezing during donation can cause minor needle movement. Having tissues within reach helps you manage symptoms comfortably.
4. Mention your allergies to staff — not because they'll defer you, but so they can accommodate you (tissues, comfortable position, latex-free supplies if needed).
5. Schedule around allergy shots — maintain a 24-hour gap between immunotherapy injections and plasma donation.
6. Don't donate during an active severe reaction — if you're experiencing hives, swelling, wheezing, or any sign of anaphylaxis, wait until symptoms fully resolve.

Frequently Asked Questions