In other trials with low-dose IL-2, risks have been minimal compared to the well-known side effects of high dose IL-2. Risks of low-dose IL-2 include some potential side effects, such as pain or skin reactions at the injection site, with potential discomfort, redness, swelling, or even a scab at the injection site; flu-like symptoms, nausea, and diarrhea. Unexpected risks are always possible.