Propolis – that gummy substance collected by bees from leaf buds and tree bark – may be helpful in preventing and shortening the duration of the common cold in both children (Rom J Virol, 1995; 46: 115-33) and adults (Otolaryngol Pol, 1989; 43: 180-4).
Propolis is rich in bioflavonoids that may be responsible for its reputed antiviral properties (J Nat Prod, 1992; 55: 294-302; Microbiologica, 1990; 13: 207). Taking 500 mg once or twice daily can also be used to treat viral infections, sore throat, and the pain and fever associated with colds and flu.