Melatonin is a hormone produced by the pineal gland that is best known for regulating the body’s circadian rhythm and signaling the onset of sleep. This natural substance is widely available as a dietary supplement and is commonly used to address various sleep disturbances. Beyond its primary role in sleep regulation, research suggests melatonin possesses other biological properties that may be relevant to respiratory health. This raises the question of whether this common sleep aid can offer any benefit for individuals experiencing a cough.
Melatonin and Relief from Nocturnal Cough
A cough often feels worse at night because lying down allows post-nasal drip or stomach acid to more easily irritate the upper airway, which triggers the cough reflex. This nocturnal exacerbation frequently leads to fragmented sleep and poor rest quality. Melatonin can indirectly provide relief by addressing the sleep disruption caused by the persistent coughing.
By improving sleep onset and maintenance, melatonin helps the body achieve the necessary rest for recovery. The resulting improvement in sleep quality mitigates the distress and exhaustion associated with a cough that keeps a person awake. The body’s ability to repair and recuperate is enhanced when sleep is uninterrupted, which can make the overall experience of having a cough more manageable.
Non-Sleep Functions of Melatonin Relevant to Cough
Melatonin’s potential to help with a cough extends beyond its sedative effects, involving its powerful antioxidant and anti-inflammatory properties. The process of coughing is often triggered by inflammation and irritation within the respiratory tract. Melatonin has been shown to reduce the expression of pro-inflammatory cytokines, such as IL-6 and TNF-α, which are involved in the inflammatory response in the airways.
As a potent antioxidant, melatonin can scavenge damaging free radicals and upregulate the body’s own antioxidant enzymes, protecting lung tissue from oxidative stress. Studies suggest that melatonin treatment decreases oxidative stress levels, which in turn relieves airway inflammation and chronic cough induced by environmental pollutants. Melatonin may also modulate the immune response, contributing to a calmer airway environment.
Another potential mechanism involves its role in conditions like Gastroesophageal Reflux Disease (GERD), a frequent underlying cause of chronic cough. Melatonin is present in high concentrations within the gastrointestinal tract and may help strengthen the lower esophageal sphincter. Strengthening this sphincter can reduce the backward flow of stomach acid into the esophagus, a common trigger for a chronic cough. Clinical evidence suggests that melatonin supplementation may improve GERD symptoms.
Practical Applications and Considerations
Clinical research has investigated melatonin’s use for coughs related to specific underlying conditions, such as GERD. For this application, studies have suggested starting doses between 3 to 6 milligrams daily, which have been shown to help manage symptoms and support the function of the lower esophageal sphincter. For general sleep support, which indirectly helps with nocturnal cough, a typical starting dose is often lower, around 1 to 5 milligrams taken an hour before bedtime.
It is important to understand that melatonin is not a substitute for a prescription anti-tussive medication, and its use for cough is primarily considered supportive. While generally well-tolerated, side effects can include daytime drowsiness, dizziness, and headache. Melatonin can also interact with several types of medications, and caution is necessary.
Individuals taking blood thinners (like warfarin) or those with diabetes should consult a doctor, as melatonin may increase the risk of bleeding or affect blood sugar regulation. Combining melatonin with central nervous system depressants, including certain cough medicines, can heighten the sedative effects. A persistent cough requires a medical diagnosis to determine the underlying cause before starting any new supplement regimen.