 [ Symptoms ] is there a safe dosage of benadryl i can give my 5 month old baby who is battling a very congested nose [ Disease ] benadryl is not a nasal decongestant and will do nothing for the stuffy nose not to mention this medication should not be given to a child this young  you want to use saline drops to help thin out the mucus in the nose and then use a nasal aspirator to help clear the passageway i also recommend running a vaporizer in the baby is bedroom    that usually helps a lot as well for congestion parents need to be very careful about cough and cold medications in infants and children so take the time to talk to your pharmacist