Hi, Gammaglobulin is used by the specialist doctor for immunodeficiency states. While few side effects are common like body aches, headache and chills but are not significant. Sometimes low BP is reported. The more serious side effects are all those like related with blood transfusion which may need urgently stopping the drugs. These include allergy including anaphylaxis, acute kidney injury, aseptic meningitis, acute lung injury. These are rare but need special consideration. For the same reason, the infusing is initially given very slowly and monitored closely. Transmission of the disease is another remote possibility. Mostly it s safe. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Mahboob Ur Rahman, General & Family Physician