Is It Okay to Eat Onions When You Have a Cough? Benefits and Risks

December 29, 2025 •

3 min read

People have used onions for coughs for centuries. Onions can soothe sore throats and clear congestion.

Quick Summary

Onions have properties that may relieve a cough and ease congestion. Prepare onions carefully; raw onions may irritate the throat, while cooked onions are typically gentler.

Key Points

Expectorant Properties: Onions have sulfur compounds that can help loosen mucus during a cough.
Anti-inflammatory Benefits: The quercetin in onions can help reduce inflammation in the airways.
Raw vs. Cooked: Raw onions can irritate a sore throat, while cooked onions are gentler and still have benefits.
Traditional Syrups: Onion and honey syrup is a folk remedy that combines the expectorant properties of onion with the soothing effects of honey.
Medical Caution: Home remedies like onion syrup are not a substitute for medical advice, especially for severe or worsening coughs.
No Honey for Infants: Never give honey or any honey-based remedy to children under one year old, due to the risk of infant botulism.
Soothing Warmth: Warm onion broths and soups can help soothe a sore throat and provide hydration.

Benefits of Onions for Coughs

Onions have properties that can help with cough symptoms. These properties include:

Natural Expectorant: Onions have sulfur compounds that are natural expectorants. Expectorants help loosen mucus in the respiratory tract, making it easier to cough up.
Anti-inflammatory and Antioxidant Power: Onions contain antioxidants, including quercetin. Quercetin may help reduce swelling and irritation in the airways and lungs.
Antimicrobial Effects: Onions may help fight bacteria or viruses causing the respiratory infection.
Immune System Support: Onions have vitamin C, antioxidants, and other nutrients that can help boost the immune system.

Raw vs. Cooked Onions for Cough Relief

The way you prepare onions can affect their impact on a cough.

Raw Onions: Potent but Potentially Irritating

Raw onions have the highest concentration of sulfur compounds. These compounds can cause irritation.

Pros: Maximum sulfur compound content for potent expectorant action.
Cons: Can cause a burning sensation in the throat. Can also trigger heartburn or acid reflux.

Cooked Onions: Milder and Still Effective

Cooking onions changes their chemical composition, reducing some of the harsh compounds. This makes them more soothing for a raw or sore throat.

Pros: Gentler on a sore throat and less likely to cause irritation or acid reflux. Still provides anti-inflammatory and immune-boosting benefits, especially in soups or broths.
Cons: Some loss of volatile sulfur compounds compared to raw.

Comparison: Raw vs. Cooked Onions for Cough


Feature	Raw Onions	Cooked Onions
Symptom Relief	Strong expectorant action, antimicrobial effects.	Soothing, anti-inflammatory, immune-boosting effects.
Effect on Throat	Potentially irritating or burning due to high sulfur compound content.	Much gentler and soothing for a sore or sensitive throat.
Best for	Individuals who can tolerate the strong flavor and potential irritation for a potent expectorant effect.	Those with sore or dry throats, or sensitive digestive systems. Excellent in soups.
Preparation	Can be chopped and mixed with honey, or consumed raw in salads.	Best in warm broths, soups, or as a honey syrup heated gently.

Onion Home Remedies for Cough

Onion and Honey Syrup: This is an effective combination. The honey soothes the throat, while the onion contributes expectorant properties. Layer sliced onions in a jar and cover with raw honey. Let the mixture sit for at least 8 hours or overnight. Strain the liquid and take by the spoonful.
Warm Onion Broth: Simmering onions in water can be comforting. Add other immune-boosting ingredients like garlic, ginger, and turmeric. This broth can hydrate and soothe a sore throat.
Onion Poultice: For chest congestion, sauté chopped onions until soft, wrap them in a cloth, and apply the warm compress to the chest. The warmth and inhaled vapors can help loosen mucus and promote circulation.

Precautions and When to See a Doctor

Onions are complementary remedies, not replacements for medical treatment.

Do not give honey to children under 1 year old due to the risk of infant botulism.
For persistent or severe coughs, see a doctor. Seek medical advice if your cough lasts more than a week, or is accompanied by fever, shortness of breath, or discolored phlegm.
Be mindful of throat irritation with raw onions, particularly if you have a sore throat or acid reflux. Cooked preparations are a safer alternative.
Always consult a doctor before starting new remedies, especially if you have underlying health conditions or are taking medications.

Conclusion

Eating onions when you have a cough may offer relief. Onions can help soothe a sore throat and clear congestion. Understanding the difference between raw and cooked preparations is key. Always combine these home remedies with rest, fluids, and professional medical advice when necessary. For more detailed research on onion compounds, consult scientific resources.

Frequently Asked Questions

Yes, raw onions contain sulfur compounds that act as expectorants. These compounds can irritate a sore throat, so cooked onions or syrups may be a better option.

Yes, onion and honey syrup is a folk remedy for coughs. Honey soothes the throat while the onion helps combat infection and clear congestion.

No, while cooking reduces some volatile sulfur compounds, cooked onions retain anti-inflammatory antioxidants like quercetin and provide a soothing effect.

Onions have expectorant properties from their sulfur compounds, which help thin and loosen the mucus. Applying a warm onion poultice to the chest can also help loosen mucus.

Onions are a complementary remedy to help alleviate symptoms and support your body's recovery. They are not a cure for the cough, and medical advice should be sought for severe or persistent symptoms.

The best preparation depends on your symptoms. For a sore throat, a warm broth or honey-based syrup is more soothing. For maximum expectorant effect, a raw onion and honey mixture is used in folk medicine.

Generally, it is safe, but consult a healthcare professional, especially if you have other health concerns or are taking medication. The risk of infant botulism from honey is a notable exception.