What are the effects of treatments for common cold?
Likely to be beneficial	Antihistamines (may improve runny nose and sneezing, no significant difference in overall symptoms)
	Decongestants (norephedrine, oxymetazoline, or pseudoephedrine provides short-term [three to 10 hours] relief of congestive symptoms)
Unknown effectiveness	Analgesics or anti-inflammatory drugs
	Decongestants (insufficient evidence to assess longer-term [more than 10 hours] effects on congestive symptoms)
	Decongestants plus antihistamines
	Echinacea
	Steam inhalation
	Zinc (intranasal gel or lozenges)
Unlikely to be beneficial	Vitamin C
Likely to be ineffective or harmful	Antibiotics