Does Donating Plasma Compromise Your Immune System?


Thinking about donating blood one day? Approximately 118.5 million people worldwide donate blood every year, and you could be one of them.1 While the thought of donating blood might seem daunting, it is a very safe and invaluable procedure that can help many people all over the world in need of blood donations.

All about blood

Types of blood cells

Blood is mostly composed of plasma: a transparent, straw-coloured fluid. Plasma contains 3 categories of blood cells: red blood cells, white blood cells, and platelets. Platelets are responsible for the clotting in the blood, while red blood cells carry oxygen through your body, and white blood cells fight threatening infections. 

Why do we need plasma?

Plasma consists of almost 90% water and is the perfect transporting medium for cells and other substances to pass through our bodies.2 Plasma also contains essential minerals, sugars, fats, vitamins, and hormones. It has the highest percentage in our total blood volume (~ 55%) and is made up of over 700 proteins.2 

When plasma is separated from the other blood cells by centrifuging blood samples at a fast rate, it can be made into transformational medicine or used in blood transfusions. Plasma is mainly used to aid the blood clotting process and to fight off diseases like immunodeficiency, genetic lung disease, and haemophilia. Have you ever been cut or wounded? Right before scabbing over, have you ever noticed a clear yellowish substance that forms over the wound, eventually drying down and stopping the blood? That is your plasma, our body's natural bandaid! This process is called coagulation, and it is where the special proteins fibrinogen, thrombin, and factor x all work together to limit blood loss.

Additional functions and uses of plasma:

  • Immunity – Plasma is also essential in providing our body’s natural immunity. The proteins found in plasma have several disease-fighting properties (mainly antibodies and immunoglobulins). It is an essential part of our immune system to help fight harmful pathogens.
  • Regulation of Blood Pressure and Volume – Plasma in the blood helps maintain our blood pressure and blood volume, as well as pH levels and body temperature. By maintaining the pressure in our bodies, plasma prevents any leakages and ensures that our blood continues to flow seamlessly through our blood vessels. It also acts like a buffer which keeps our blood at an optimal pH level to support healthy cellular function. 
  • Blood Transfusions – When plasma is extracted from individuals that have donated their blood, it can be frozen to preserve its freshness. It can then be transported to hospitals and other processing centres to be further made into a concentrated dose that is richer than raw plasma. This is called cryoprecipitate. 

Who requires a plasma transplant?

Since plasma is usually used to replenish low levels of clotting factors, it is the perfect treatment for patients who have liver disease or genetic predispositions to low/missing clotting factors in their blood. Patients who are undergoing liver or heart surgery may also need plasma transplants due to the high blood loss, although not in every instance. 

Donating Plasma

How do you donate plasma?

Donating plasma can be a very fulfilling experience. Firstly, a nurse or doctor will give you a health questionnaire to fill out. This is to ensure that your medical facility is aware of your medical history and has a record of any concerns. Then, you will be checked for your iron levels, veins, and pulse. If a cause of concern arises and you are not eligible to donate, the staff will let you know. 

Next, your blood will be drawn from a vein in one of your arms. It takes approximately 40 minutes to fill up one bag of plasma. The plasma that is collected in the blood bag will be put in a machine that will separate your red blood cells from your plasma. When this process is done, your red blood cells will be put back into your body using the same needle. It’s that simple! You will have time to unwind and rest afterwards, as well as receive some snacks and drinks. 

Short term effects

Knowing about the short-term effects of donating plasma will help you make a more informed decision about whether or not you would like to donate. Although the process is relatively simple, you may experience some immediate side effects after donating. These include:

  1. Dizziness or lightheadedness – This happens because as your blood is drawn, it “removes” a lot of water. It will cause mild dehydration but nothing too extreme and can easily be rectified by replenishing the water afterwards. 
  2. Hunger and tiredness – This occurs due to the electrolyte imbalance that comes with drawing blood. 
  3. Bruises – You may also get bruised or feel a bit of discomfort after donating plasma. This typically occurs at the needle insertion site. Make sure to let the staff know if it ever feels too intense.
  4. Infections or inflammation – On rare occasions, there is a possibility that you might get an infection or inflammation may occur at the needle insertion site. This is treatable and is a low-risk, short-term effect. The inflammation you might feel would be a warm feeling of pain or swelling. Please contact the donation centre if you have concerns.

In order to prepare your body for the plasma donation process, there are several things that you can do to make sure the process is as smooth as possible, some of which are listed below.

  • Make sure to drink plenty of water, fruit juice, or caffeine-free drinks 2-3 hours before your session. This will keep you hydrated. 
  • Avoid nicotine, alcohol, and caffeine. These will render your plasma inadmissible or prevent you from donating in the first place. 
  • Eat a healthy and filling meal before donating to prevent the feeling of fatigue. 

Long-term effects and risks

If you are healthy, donating plasma will have very minimal effects on your body. The NHS states that you can safely donate plasma every two weeks; however, people assigned female at birth (AFAB) must wait 16 weeks between blood donations and people assigned male at birth must wait 12 weeks.4 This is because the blood you have donated will be replenished by your body in 4 to 8 weeks; whereas, the plasma is replenished within 48 hours.5 It would not deplete your iron or cause any anaemia. However, if you do donate regularly, there is a slight risk of immunoglobulin depletion. This is the ability of your body to fight infections, making you more prone to getting sick. Always check with your doctor to make sure your levels are not dangerously slow. 


As you can see, plasma is a very important component of life. This yellowish clear liquid is an essential part of keeping our bodies healthy and functioning. While helping us out with our immunity, clotting our blood, and maintaining our blood pH, pressure, and volume, it also transports nutrients and proteins throughout our bodies. 

If you are eligible to donate blood, please consider donating your plasma. It is in very high demand and is essential in treating many life-threatening diseases. Sometimes even marking the difference between life and death!


  1. Blood safety and availability [Internet]. [cited 2022 Jun 28]. Available from:
  2. Mathew J, Sankar P, Varacallo M. Physiology, blood plasma. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited 2022 Jun 28]. Available from:
  3. How to donate plasma [Internet]. NHS Blood Donation. [cited 2022 Jun 28]. Available from:
  4. How to donate plasma [Internet]. NHS Blood Donation. [cited 2022 Jun 28]. Available from:
  5. What are the side effects of donating blood? [Internet]. HDFCErgo. [cited 2022 Jun 28]. Available from:

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