Li 2005a.

Methods	Randomised trial Duration: unclear
Participants	Country: Eastern China Population: infertile men with oligoasthenospermia, N = 80 Mean age: 29 ± 3.5 (23 to 40) years Inclusion criteria: no smoking or alcohol, any fertility medication needed to be stopped 2 weeks before Exclusion criteria: none
Interventions	L‐carnitine 2 g (n = 40) versus Vitamin E 100 mg + Vitamin C 200 mg (n = 40) Duration of treatment: 3 months
Outcomes	Seminal parameters, pregnancy rate
Notes	Article in Chinese, translated by Shaofu Li 10.11.2008. Attempted to contact author re methods of randomisation, concealment and whether SD or SEs used and whether this is the same trial as Li 2005. Also asked whether there were any data on pregnancy rate. Translator replied 22.09.2009 no pregnancy data were available in the text of the trial
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not mentioned
Allocation concealment (selection bias)	Unclear risk	Not mentioned
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not mentioned
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not mentioned
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Withdrawal: 8 from treatment (n = 32) and 9 from control (n = 31). 21% loss to follow‐up. No ITT
Selective reporting (reporting bias)	Unclear risk	No protocol available.