Table 1. MEDLINE search strategy^a.

Design search terms
	1. Control*
	2. Random*
Intervention search terms
	3. Acetylcysteine
	4. Alpha-tocopherol
	5. Alpha-tocotrienol
	6. Antioxidant*
	7. Arginine
	8. Ascorb*
	9. Astaxanthin
	10. Bilberry extract
	11. Carnitine
	12. Carotenoid*
	13. Coenzyme Q10
	14. Co enzyme Q10
	15. CoQ 10
	16. Curcumin
	17. Flavonoid*
	18. Folacin
	19. Folate
	20. Folic acid
	21. Folvite
	22. Ginseng
	23. Glutathione
	24. Green tea
	25. L-acetylcarnitine
	26. L-arginine
	27. L-carnitine
	28. L-citrulline
	29. Levocarnitine
	30. Lutein
	31. Lycopene
	32. Melatonin
	33. N-acetylcysteine
	34. Polyphenol*
	35. Pomegranate
	36. Pycnogenol
	37. Quercetin
	38. Radical scavenger
	39. Resveratrol
	40. Selenium
	41. Ubiquinone
	42. Vitamin C
	43. Vitamin E
	44. Zinc
Diagnosis search terms
	45. Androgen deficien*
	46. ED
	47. Erectile dysfunction
	48. Erectile function
	49. Hypogonadism
	50. IIEF
	51. Impotence
	52. International Index of Erectile Function
	53. Sexual dysfunction
	54. Sexual function
Combination terms
	55. or/1–2
	56. or/3–44
	57. or/45–54
	58. and/55–57

^aThe ‘^*’ represents a wildcard symbol used in a search query to represent end truncation.