Cough Medicine Is Ineffective and May Be Dangerous

Analysis by Dr. Joseph Mercola Fact Checked

cough medicine ineffective

Story at-a-glance -

  • To date, research has not demonstrated over-the-counter (OTC) cough medications are effective, and cough medicine can trigger significant side effects, especially in children
  • Colds cost the U.S. economy nearly $40 billion a year and are often associated with coughing; a cough is the most common reason children are brought to their physicians, and colds are the most common reason children miss school and adults miss work
  • Coughing may become irritating and disrupt sleep, but it is an effective mechanism your body uses to clear airways of mucus and foreign objects; even if a majority of your cold symptoms resolve within two weeks, your cough may persist for several weeks afterward
  • Calm your cough naturally without side effects using raw honey, salt water or herbs such as eucalyptus, peppermint, anise, slippery elm and fennel (and their oils), which act as cough suppressants

It may start as a tickle in the back of your throat, or a full throttled bark as you try to clear a growing amount of secretions in your upper respiratory tract. But, however it begins, most would like the coughing to stop.

Usually a cough will accompany a cold, beginning as a runny nose, scratchy throat and sneezing. A cold is caused by a virus, the most common of which is the rhinovirus. It may be responsible for up to 50 percent of all colds. According to the Centers for Disease Control and Prevention (CDC),1 most get colds in the winter and spring, but it is possible to experience a cold anytime of the year.

Although you're likely to recover from most symptoms within 10 days, your cough may continue for several weeks. Each year, millions in the U.S. get the common cold. The CDC estimates2 the average adult will have two to three colds per year and children tend to have even more bouts. It is the main reason children miss school and adults miss work.

Socioeconomic Burden of Coughing

Coughing is one of the most common reasons for medical consultation, both among children and adults. In a study3 evaluating the impact of coughing in an employee population in Finland, researchers found coughing decreased the quality of life for the adults and had a socioeconomic impact by increasing doctor's office visits and sick days.

Research published in PLOS ONE4 evaluated data based on how coughing varied by age and sex in a pediatric population. In a group of over 7,500 children, 10 percent of the children coughed more than others and 69 percent coughed when they had a cold.

Coughing was more common in boys than girls in the first decade of life, but the differences were not statistically significant in the early teens, eventually reversing by age 14. The researchers suggested5 meta-analyses of multiple studies are only valid when similar questions and age groups are compared.

As most parents can likely attest, coughing disturbs sleep in children and parents alike. In one study,6 researchers found it disturbed sleep in 88 percent of children and 72 percent of parents. Another study7 found a cough is the most common reason children are brought to their physicians and are more common in preschoolers than older children.

Upper respiratory tract infection or acute bronchitis are two diagnoses representing at least 75 percent of all reasons for a cough seen in the doctor's office.8 Symptom relief is often what drives people to see their doctor or health care provider when they have a cold and cough.

However, over-the-counter (OTC) cough suppressants have been found to be ineffective and may even be dangerous. Despite such evidence, cough medicines are still commonly given to children.9

There's No Proof OTC Cough Medications Work

According to the Consumer Healthcare Products Association,10 the number of allergy sufferers using OTC medications has risen from 66 percent to 75 percent, and nearly 70 percent of parents have given their child an OTC medicine at night to ease a sudden medical symptom.

Data also shows colds cost the U.S. economy nearly $40 billion each year, substantially more than other chronic health conditions, such as heart failure and emphysema.11 Researchers have also found the average consumer spends $338 per household each year on OTC medications.12

With all this money spent on OTC medications to provide symptom relief, you might have assumed what was being purchased is effective and safe. However, there is a lack of evidence for value in any of the OTC remedies often used to treat cough.

Dr. Norman Edelman, pulmonologist at Stony Brook University School of Medicine and scientific adviser at the American Lung Association, spoke to a New York Times13 reporter suggesting people anxious for relief are convinced cough medicines work. Although he didn't state cough medicines don't work, he commented that, as yet, there is no proof they do.

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Pediatricians Recommend You Don't Use Cough Medicine in Young Children

Unfortunately, there is proof they can have significant side effects and may be hazardous for children and those who suffer from high blood pressure or congestive heart failure. For instance, a common ingredient found in cough syrups, dextromethorphan, has had a history of drug abuse since the 1960s.14

In high doses, the drug can cause abnormal heartbeat and sedation, but it also creates a sense of euphoria and can lead to hallucinations. Misuse of dextromethorphan is responsible for an estimated 6,000 visits to the emergency room by teens every year.15

The drug can also negatively affect those suffering from asthma, diabetes, liver disease, chronic bronchitis or emphysema. Additionally, there is a long list of medications with which dextromethorphan will interact.16

Promethazine, an antihistamine used to block allergic reactions, sometimes found in cough medicines, has a direct central effect and comes with side effects such as sedation, disorientation, hallucinations, muscle spasms and catatonic states.17

The American Academy of Pediatrics18 says cold and cough medicines should not be recommended, prescribed or used for respiratory illnesses in young children, as research demonstrates very little benefit and potentially serious side effects.

What's in Cough and Cold Medicines?

Medications commonly recommended for cough and cold in children fall into four categories — decongestants, cough suppressants, antihistamines and expectorants. Collectively, these are known as cold medications and are often combined in products, increasing the risk for overdose when more than one medication is used.

Decongestants — Decongestants include the active ingredients pseudoephedrine and phenylephrine, which work by shrinking the lining of your nose and decreasing secretions. However, they also raise your heart rate and blood pressure, and can trigger hyperactivity, agitation and sleeplessness in children.19

Cough suppressants — A common active ingredient in cough suppressants is dextromethorphan, but evidence of its effectiveness is weak.20

Studies evaluating the combination of codeine and dextromethorphan in children has not been found effective,21 and in one study comparing codeine, dextromethorphan and a combination of codeine and dextromethorphan against a placebo, researchers found none was significantly more effective than a placebo.22

Antihistamines — Research has found that while antihistamines may help reduce symptoms, the risks far outweigh the benefits.23

Expectorants — The fourth type of cough and cold medications are expectorants that are supposed to thin mucus to make it easier to expel. The active ingredient in expectorants, guaifenesin, is marketed under the brand name Robitussin. According to the American Family Physician, despite broad use, studies have been inconsistent in supporting the effectiveness as an expectorant.24

In one study published in Respiratory Care,25 researchers reported the results of a double-blind, randomized, placebo-controlled trial examining the effects on volume and physical properties of sputum. The researchers found guaifenesin did not work as an expectorant, and did not increase the volume of sputum, compared to placebo.

Beware of Codeine

It's important to remember to never give your child a cough suppressant containing codeine, as it is a habit-forming opiate. As noted in Medline:26

"Codeine may cause serious or life-threatening breathing problems, especially during the first 24 to 72 hours of your treatment and any time your dose is increased …

When codeine was used in children, serious and life-threatening breathing problems such as slow or difficulty breathing and deaths were reported. Codeine should never be used to treat pain or a cough in children younger than 18 years of age. If your child is currently prescribed a cough and cold medicine containing codeine, talk to your child's doctor about other treatments."

Coughing — Healthy But Irritating

Coughing is a normal reflex your body uses to clear airways of small particles, mucus or microorganisms. However, as described by researchers,27 the common form of cough caused by an upper respiratory tract infection is actually a natural defense mechanism hijacked by a virus in order to infect others.

Despite the resolution of the majority of your cold symptoms within 10 days to two weeks, your cough may persist for several weeks afterward. In fact, 1 in 10 children will be coughing well past three weeks after their cold began, and while irritating to child and parent, the cough does not need medical treatment.28

Instead, consider the natural cough remedies below to help calm the cough and get some rest. Researchers29 are studying how the virus hijacks your coughing reflex long after the original infection has been cleared in order to help reduce the spread of colds and the socioeconomic impact it has on society.

The virus increases mucus production along your respiratory tree, extending from your nose to deep in your lungs. If the mucus remains, it attracts bacteria that may eventually trigger more inflammation, mucus and a bacterial infection.30

Coughing helps your body get rid of the mucus before bacteria has a chance to replicate. Your coughing reflex brings the mucus out of the lungs and agitates the mucus, preventing bacteria from replicating and developing biofilm. As such, coughing is actually helping prevent more serious illness.

When to Seek Medical Attention

While common after a cold, not all coughing is benign. It's important to recognize the differences and know when you can treat a cough at home using natural remedies and when it's important to seek medical attention.

If your child has not had a recent cold or has additional symptoms, such a fever, listlessness, blood in the sputum, difficulty breathing and mood changes, it is time to seek medical attention. Aside from a cold, coughing may be triggered by:31,32

Bronchitis and pneumonia

Chronic obstructive lung disease

Exposure to very dry, cold air

Gastroesophageal reflux


Post nasal drip

Medication side-effect

Whooping cough

Inhaled foreign object


Fungal infection

Sinus infection

Lung cancer



Airborne irritant

Steer Clear of Antibiotics

It's also important to steer clear of antibiotics as they are effective only against bacteria and not against viruses that cause the common cold. Overuse of antibiotics worldwide has led to a global crisis of antibiotic resistance, which the CDC33 calls "one of the most urgent threats to public health."

Every year at least 2 million Americans are infected with antibiotic-resistant bacteria, and according to the most recent calculations, multidrug-resistant infections are now killing anywhere from 82,276 to 91,207 people per year.34 Antibiotics do save lives, but 30 percent are prescribed unnecessarily in the doctor's office and emergency departments.35

According to the CDC,36 antibiotics are not effective against health conditions caused by viruses, such as the cold, flu, bronchitis and runny noses. Despite what you may have heard, even when mucus is thick, yellow or green you may still have a viral infection.

While antibiotics can save lives, when used unnecessarily, the risks outweigh the benefits. Some of the common side effects can include rash, dizziness, nausea and yeast infections. Another long-term side effect is the damage done to your gut microbiome. Find more information in my previous article, "Antibiotics Send 70,000 Kids to the ER."

Help Is as Close as Your Kitchen

Prevention is the best medicine. In my previous article, "How Long Does a Cold Last?" I discuss several strategies you may use to help support your immune system and prevent contracting a viral illness. Calming your cough may be as close as your kitchen cabinet. Consider trying the following natural remedies to soothe your cough:

Apple cider vinegar — The antibacterial properties in apple cider vinegar may help your sore throat and soothe your cough. Gargle with a mixture of one-third cup apple cider vinegar with warm water as needed.

Herbal remedies — Herbs such as eucalyptus, peppermint, anise, slippery elm and fennel (and their oils) act as cough suppressants. One study found an echinacea/sage throat spray worked just as well as a chlorhexidine/lidocaine spray in relieving sore throats in children.37

Raw honey — Raw honey has antiviral and antibacterial properties, and may also support your immune system. It has also been found to relieve symptoms of upper respiratory tract infection in children38 and is as effective as dextromethorphan at relieving a cough without the side effects.39

Salt water — One of the simplest ways to soothe a sore throat often associated with a cough is to gargle with natural salt, which helps kill bacteria, ease sore throat pain and prevent upper respiratory tract infections.40 Salt water may also reduce the buildup of phlegm at the back of the throat, reducing your cough trigger.41 Try a solution of one-half teaspoon salt in one-half cup of warm water.

A nasal saline rinse can also effective in treating viral infections and recurrences. It may also help thin mucus secretions. These should only be done with sterile normal saline water as tap water may increase the inflammatory response and carries parasites.42,43

+ Sources and References