Total sperm motility at 6 months(data not suitable for meta analysis)
Study	Intervention	Control	P value
Carnitines
Cavallini 2004	L‐carnitine + Acetyl‐carnitine Median = 23.6 (n = 39) Interquartile range = 28.9 ‐ 16.0	Placebo Median = 13.2 (n = 47) Interquartile range = 18.6 ‐ 9.0	Not provided
Folic acid
Wong 2002	Folic acid Median = 35 (n = 22) Range = 5 ‐ 65	Placebo Median = 30 (n = 25) Range = 5 ‐ 80	Not provided
Zinc
Wong 2002	Zinc Median = 35 (n = 23) Range = 10 ‐ 65	Placebo Median = 30 (n = 25) Range = 5 ‐ 80	Not provided
Zinc + Folic acid
Wong 2002	Zinc + Folic acid Median = 35 (n = 24) Range 5 ‐ 70	Placebo Median = 30 (n = 25) Range = 5 ‐ 80	Not provided
Combined antioxidants
Micic 2017	Proxeed Plus Median = 31.0 (20.0 ‐ 41.0) (n = 125 ) Median (interquartile range) Progressive sperm motility	Placebo Median 29.0 (15.5 ‐ 35.5) (n = 50) Median (interquartile range) Progressive sperm motility	Not provided