Comparison 1. S‐Adenosylmethionine versus placebo.

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Pain	2	533	Std. Mean Difference (Random, 95% CI)	‐0.17 [‐0.35, 0.01]
2 Function	3	542	Std. Mean Difference (Random, 95% CI)	0.02 [‐0.68, 0.71]
3 Number of patients experiencing any adverse event	4	623	Risk Ratio (IV, Random, 95% CI)	1.27 [0.94, 1.71]
4 Number of patients who withdrew because of adverse events	4	656	Risk Ratio (IV, Random, 95% CI)	0.94 [0.48, 1.86]