Table 1

First author/ year	Country	Study design	Mean age, years (I/C)	Sample size (I/C)	Type of intervention	Intervention dose (mg/ day)	Control group	Outcomes contributed	Duration of intervention	Quality assessment
Table 1. General characteristics of the included RCTs
Ahmadian et al., 2023	Iran	RCT	34.79/ 33.53	21/19	Capsule	800 / 1 time	Pentoxifylline /800 mg	Sperm motility (Fig. 4A) Testosterone (Fig. 5A)	12 weeks	Fair
Sanagoo et al., 2021	Iran	TRCT	35.04/ 34.88	25/24	Capsule	1500 / 1 time	Vitamin E	Sperm motility (Fig. 4A) Sperm count (Fig. 4B) Sperm morphology (Fig. 4C) FSH (Fig. 5B) LH (Fig. 5C)	90 days	Good
Aghajani et al., 2021	Iran	RCT	35.57/ 34.40	30/30	Syrup	750 / 2 times	Vitamin E	Sperm motility (Fig. 4A) Sperm count (Fig. 4B) Sperm morphology (Fig. 4C) Testosterone (Fig. 5A) FSH (Fig. 5B) LH (Fig. 5C)	90 days	Good
Pilehvari et al., 2023^*	Iran	BRCT	33.67/ 34.83	27/23	Capsule	500 / 3 times	Placebo	Excluded from meta-analysis	12 weeks	Poor
Mahdiani et al., 2018	Iran	BRCT	31.08/30	29/28	Capsule	500 / 3 times	Placebo	Sperm motility (Fig. 4A) Sperm count (Fig. 4B) Sperm morphology (Fig. 4C) Testosterone (Fig. 5A) FSH (Fig. 5B) LH (Fig. 5C)	12 weeks	Poor

a RCT: Randomized controlled trial; b BRCT: double-blind randomized controlled trial; c TRCT: triple-blind randomized controlled trial.
* Pilehvari et al. (2023) was included in the systematic review but excluded from all quantitative meta-analyses due to reporting of sperm parameters as percentages without extractable mean and standard deviation values.