The most common over-the-counter option for a dry cough is dextromethorphan, a cough suppressant found in products labeled “DM.” It works by dialing down activity in the part of the brain that triggers the cough reflex. But depending on what’s causing your cough, a suppressant may not be your best or only option. Honey, prescription medications, and simple home remedies can all play a role.
Over-the-Counter Cough Suppressants
Dextromethorphan is the active ingredient in most OTC dry cough products. You’ll find it in syrups, capsules, and lozenges, often under brand names like Robitussin DM or Delsym. The standard adult dose for the immediate-release form is 10 to 20 mg every four hours, with a maximum of 120 mg in 24 hours. Extended-release versions are taken less often, typically 60 mg every 12 hours.
One thing to watch: many combination cold products also contain dextromethorphan alongside decongestants or pain relievers. If you only have a dry cough, look for a product that lists dextromethorphan as the sole active ingredient. Stacking multiple medications you don’t need increases the chance of side effects like drowsiness or nausea.
For children, the rules are stricter. The FDA does not recommend OTC cough and cold medicines for children under 2, citing the risk of serious side effects. Manufacturers voluntarily label these products with a warning not to use them in children under 4. For kids aged 4 to 12, doses are significantly lower, and you should follow the weight and age guidelines on the package carefully.
Honey: A Surprisingly Effective Option
Honey is not just a folk remedy. In a clinical trial comparing buckwheat honey to dextromethorphan in children with nighttime cough, honey actually performed better. Parents rated cough frequency improvement at 1.89 points on a 6-point scale for honey, compared to 1.39 points for dextromethorphan and 0.92 points for the control group. Cough severity scores were nearly identical between honey and dextromethorphan.
A spoonful of honey before bed coats the throat and may reduce the tickle that keeps triggering the cough reflex. For children aged 2 to 5, half a teaspoon is appropriate. Kids 6 to 11 can take a full teaspoon, and those 12 and older can take two teaspoons. Never give honey to a child under 1 year old because of the risk of infant botulism.
Prescription Options for Stubborn Coughs
If OTC suppressants aren’t cutting it, doctors sometimes prescribe benzonatate (sold as Tessalon Perles). Unlike dextromethorphan, which acts on the brain, benzonatate works locally by numbing the stretch receptors in your airways and lungs. These receptors are what detect irritation and send the “cough now” signal, so dulling them quiets the reflex at its source.
Benzonatate comes in soft capsules that you must swallow whole. Chewing or dissolving them in your mouth releases a numbing agent that can temporarily anesthetize your tongue, mouth, and throat. This isn’t just uncomfortable. It can cause choking and airway problems. If you accidentally bite into one and notice numbness or tingling, avoid eating or drinking anything until the sensation passes completely.
Treating the Cause, Not Just the Cough
A dry cough that lingers is often a symptom of something else. Three of the most common culprits are postnasal drip, acid reflux, and asthma. Suppressing the cough without addressing the underlying cause means it keeps coming back.
Acid reflux is a particularly sneaky trigger. Stomach acid creeping up into the esophagus can irritate the throat and airways enough to produce a chronic dry cough, sometimes without any heartburn at all. Doctors often trial acid-reducing medications called proton pump inhibitors (PPIs) for a few weeks. If the cough improves on those, reflux was likely the problem. Milder acid reducers like famotidine can also help.
Postnasal drip from allergies or sinus issues sends mucus down the back of your throat, irritating it just enough to keep you coughing. An antihistamine or a nasal steroid spray can dry up the drip and stop the cough cycle. If asthma is the cause, an inhaler targeting airway inflammation is the real fix, not a cough suppressant.
Home Remedies That Actually Help
Salt water gargles are a simple way to soothe an irritated throat. Mix about a quarter to half a teaspoon of salt into 8 ounces of warm water, gargle for 15 to 30 seconds, and spit. This draws moisture into the throat tissue and can temporarily calm the tickle that triggers coughing.
Staying well hydrated matters more than most people realize. Warm liquids like tea or broth help loosen any irritation in the throat and keep the mucous membranes from drying out further. Herbal teas with marshmallow root are a traditional choice. Marshmallow root contains natural compounds called mucilaginous polysaccharides that form a coating over irritated throat tissue, reinforcing the natural mucus layer and supporting healing.
Adding moisture to your environment helps too, especially at night when dry indoor air makes coughing worse. A cool mist humidifier is the recommended choice (the American Academy of Pediatrics specifically recommends cool mist over warm steam vaporizers to avoid burn risk). Keep the humidifier sized appropriately for your room. One that’s too large creates excess condensation, which can encourage mold and bacteria growth.
When a Dry Cough Needs Medical Attention
In adults, a cough lasting longer than eight weeks is classified as chronic. At that point, it’s no longer something to manage on your own. A doctor will typically start with a chest X-ray to rule out infections, inflammation, or more serious conditions. In children, the threshold is lower: four weeks.
Before that eight-week mark, certain symptoms warrant an earlier visit. Coughing up blood, significant shortness of breath, unexplained weight loss, or a cough accompanied by a high fever that won’t break are all signs that something beyond a simple viral irritation is going on. A dry cough that worsens at night or with exercise can point toward asthma, even in adults who’ve never been diagnosed.