Researchers analyzed eight clinical trials to see if the supplement L-arginine helps people with sickle cell disease during painful episodes called vaso-occlusive crises. The analysis combined data from 830 patients who received either L-arginine or a placebo/standard care. They looked at key outcomes like pain levels, how much opioid pain medication was needed, how long the crisis lasted, and time spent in the hospital.
The main finding was that L-arginine did not show a statistically significant benefit for any of these important clinical measures. Pain scores and opioid use were not meaningfully reduced. The time it took for the crisis to resolve and the length of hospital stay were also not significantly shorter. One concerning, though not statistically certain, signal was a 23% increase in the risk of being readmitted to the hospital.
The evidence from this review is considered low certainty, meaning we cannot be very confident in these results. The analysis did not report on safety or side effects, which is an important gap. Because no clear benefit was found and there is a potential safety question about readmissions, the researchers conclude that L-arginine should not be recommended for routine use in treating sickle cell pain crises. Patients should discuss all treatment options with their doctor.