Honey and onion is a traditional cough remedy with some scientific backing, though the evidence is stronger for honey than for onion. Honey on its own has been shown in clinical trials to reduce cough frequency and improve sleep in children with acute coughs, performing slightly better than common over-the-counter cough medications. Onion brings anti-inflammatory and antimicrobial properties that may complement honey’s soothing effects, but direct clinical trials on onion as a cough treatment are limited.
What the Evidence Says About Honey
Honey is the better-studied half of this remedy. A systematic review of clinical trials found that honey reduced cough frequency by a small but meaningful margin compared to both placebo and standard cough medication, with improvements ranging from 0.2 to 1.1 points on symptom scales. Sleep quality also improved more in children given honey than in those given cough medicine or no treatment. The World Health Organization has recommended honey for cough and cold symptoms in children since 2001.
The way honey works is surprisingly interesting. Its sweetness triggers a reflex that increases saliva production and airway mucus secretion, which coats and soothes the irritated lining of the throat and voice box. This is called a demulcent effect. Beyond that, the sweet taste appears to interact with nerve fibers in the brain that help suppress the cough reflex itself, working through some of the same pathways that opioid-based cough suppressants target. So honey isn’t just coating your throat. It’s also sending signals that dial down the urge to cough.
What Onion Brings to the Mix
Onion doesn’t have the same level of clinical evidence for cough specifically, but it contains compounds with relevant properties. The sulfur-based compounds in onion, produced when the vegetable is cut or crushed, have demonstrated broad-spectrum antimicrobial activity in lab studies, including effectiveness against drug-resistant bacteria. Onion also contains quercetin, a plant compound that inhibits the release of inflammatory chemicals in the body, which could help calm inflamed airways during a cough.
Research on garlic and onion extract given daily to elderly volunteers found potential benefits for respiratory infections, and preclinical work suggests onion compounds can modulate the inflammatory response and improve lung function. The traditional logic behind adding onion to honey is that it acts as a mild expectorant, helping loosen mucus so it’s easier to clear. While the anti-inflammatory and antimicrobial properties are real and well-documented in lab settings, no large clinical trial has isolated onion’s effect on cough the way studies have for honey.
How to Make Honey and Onion Syrup
The preparation is simple. Finely chop one onion and stir it into roughly half a cup of raw honey. Let the mixture sit for about 12 hours or overnight. During this time, the honey draws liquid out of the onion through osmosis, creating a thin syrup infused with the onion’s active compounds. Stir it a couple of times while it sits if you can. After steeping, strain the mixture through a fine sieve and store the resulting syrup in a sealed jar in the refrigerator.
A typical dose is one to two teaspoons as needed for cough, up to several times a day. The syrup keeps in the fridge for a few days. Raw honey is preferred over processed varieties because heat treatment can break down some of its beneficial enzymes and compounds. If you have access to high-quality raw honey, that’s the best choice for this preparation.
Who Should Avoid This Remedy
The most important safety concern involves infants. Honey must never be given to children younger than 12 months because it can contain spores of bacteria that cause infant botulism, a serious form of food poisoning. The CDC lists this as a firm guideline, not a suggestion. Children over one year old and adults can use honey safely for cough relief.
Onion is a known trigger for digestive discomfort in some people, particularly those with irritable bowel syndrome. Onions contain fructans, a type of fermentable carbohydrate that can cause bloating, gas, and abdominal pain. In blinded studies of IBS patients, fructans from onion and garlic were among the major triggers of gut symptoms. If you know onions bother your stomach, the small amount present in strained syrup may still be enough to cause issues, so it’s worth being cautious. For most people, though, the quantity in a teaspoon or two of strained syrup is unlikely to cause problems.
How It Compares to Cough Medicine
For run-of-the-mill coughs from colds and upper respiratory infections, honey performs at least as well as the active ingredient in most over-the-counter cough syrups. The clinical differences are small, but honey consistently matches or slightly outperforms standard cough medications across multiple trials, with fewer concerns about side effects. This is particularly relevant for children, since many pediatric organizations already advise against giving common cough suppressants to young children due to limited benefit and potential risks.
Adding onion to the mix gives you a remedy that combines a proven cough suppressant with compounds that have anti-inflammatory and antimicrobial properties. Whether the onion adds meaningful clinical benefit beyond honey alone hasn’t been tested in a head-to-head trial, but the underlying science is plausible, and the combination has centuries of use across multiple folk medicine traditions. For a mild to moderate cough from a cold, it’s a reasonable and low-risk option to try before reaching for pharmacy products.