Treatment	Study type	Findings
Antibiotics	2 Cochrane reviews of 11 RCTs each46,47	No benefit for symptom duration or severity compared with no antibiotics or placebo
Antihistamine monotherapy (sedating and nonsedating)	2 Cochrane reviews of 18 RCTs and a subsequent RCT6,34	No more effective than placebo for global improvement
Antitussives and expectorants*	Cochrane review of 10 trials without meta-analysis6	No more effective than placebo for cough
Codeine	Older RCT of 82 adults48	No more effective than placebo for cough
Echinacea	Cochrane review of 24 RCTs without meta-analysis49	No more effective than placebo for reducing symptom duration or severity
Intranasal corticosteroids	Cochrane review of 3 RCTs50	No more effective than placebo for reducing symptom duration or severity
Pelargonium sidoides (African geranium)	Cochrane review of a low-quality trial51	No significant improvement by day 5
Steam	Cochrane review of 6 trials with 387 participants52	No benefit of using heated humidified air for treatment of URIs
Vitamin C	Cochrane review of 29 RCTs16	No more effective than placebo for reducing symptom duration or severity once symptoms have developed
Vitamin D	RCT of 322 adults19	No difference in URI occurrence, days of missed work, or symptom duration or severity with high-dose vitamin D supplementation (200,000 IU followed by 100,000 IU monthly)
Vitamin E	RCT of 652 adults 60 years and older 53	Significantly worse URI symptoms with daily supplementation of vitamin E (200 mg) compared with no supplementation; no difference in URI occurrence