Garlic. Garlic has long been recognized for its healing properties. Garlic contains anti-inflammatory, anti-viral and antimicrobial properties. A compound in garlic, allicin, is known to be highly antimicrobial. This compound may help fight off common colds, a frequent cause of postnasal drip. Garlic can also help to break up and dislodge pesky mucus as well as prevent excess mucus from forming. Try crushing three to four cloves of garlic, extract the juice, add some honey and drink. This can be done up to three times a day to help relieve the symptoms of postnasal drip.