Is immunosupression (after organ transplant) a contradiction to PRP for hair loss and is it safe to get it done?

You should first ask the internist in charge of your post-operative immunosuppression.  
Immunosuppression can reduce the activation of platelets.  Activation and clumping of platelets is necessary to release growth factors from the alpha granules.  Some discourage PRP treatments in combination with glucocorticoids and non-steroidal anti-inflammatory agents like Motrin.  You are probably getting a much more potent immunosuppression meant to reduce DNA replication.  
I use sound energy to burst platelets.  I get 6 to 8 times the concentration of growth factors as standard PRP and I do not need to worry about platelet activation.  
the other concern is infection, which can result from a reduction in both b and t lymphocytes.  Sterile technique should reduce this risk.  
Remember to ask your physician for his opinion.  

A lot of the contraindications and precautions regarding PRP are hypothetical. Physicians do not want to inject PRP due to the potential of infection in immunocompromised patients. Another consideration is that the growth factors can theoreticlly stimulate the original tumor. Thirdly, people with immunosuppression can have decreased platelet counts and abnormal platelet function. Ask your oncologist if they will allow you to undergo treatment. Find a PRP expert.

Hi, although PRP is not contraindicated while on immunosuppressants, I believe that you might be wasting your money while on them. PRP, in order to work effectively, relies on stimulation of the “healing response” which requires an intact immune system. I would wait for a time when you can be off of the immunosuppressive, or take a drug holiday from them. You may also want to consider amniotic fluid growth factors as well.