Common Frequent urge to urinate, Difficulty in urination, Injection site redness, Swelling of lymph nodes, Stomach upset, Vomiting, Chills, Fever.

Expert advice for Sii-Onco-BCG Injection
• You will be monitored for the presence of symptoms of systemic BCG infection and signs of toxicity such as high fever, flu-like symptoms after each treatment.
• Seek immediate medical attention if you notice any signs of infection.
• Discontinue treatment if you develop persistent fever or experience an acute febrile disease (rapid onset of fever and symptoms).
• Tell your doctor if you are to undergo diagnostic test for tuberculin skin test as treatment with BCG may alter the result. 
• Inform your doctor before you take BCG if you have any artificial joints (e.g. hip replacement) or surgical implants (e.g. pacemaker or replacement heart valve), any swelling in the wall of the artery, any disease which requires drugs which weaken the immune system or you have a small bladder.
• Patients allergic to BCG or any of its ingredients or any history of BCG reaction affecting the whole body should not take it.
• BCG should not be given to patients with compromised immune system since birth or due to conditions causing weak immune system such as AIDS, cancer therapy.
• Pregnant women and breastfeeding mothers should not be given BCG.
• Patients with concurrent infections of urinary tract, active tuberculosis infection, passing blood in the urine (hematuria), positive HIV test should not be take BCG.
• Also, patients who recently had a bladder operation or recent history of bleeding due to a tube inserted in the bladder should avoid taking BCG.