What does onion and lemon juice do to the body?

November 21, 2025 •

4 min read

Many traditional health remedies feature potent combinations of natural ingredients. For example, onions are a rich source of antioxidants like quercetin, and combining them with vitamin C-packed lemon juice can have various positive effects on the body, from boosting immunity to aiding digestion.

Quick Summary

The combination of onion and lemon juice offers numerous health benefits, including boosting immune function, supporting digestion, and providing antioxidant protection. It can also improve cardiovascular health and be used topically for hair and skin.

Key Points

Immunity Boost: The combination enhances immune function with powerful antioxidants and high vitamin C content.
Digestive Aid: Prebiotic fibers in onion and digestive enzymes stimulated by lemon support a healthy gut microbiome and regularity.
Heart Health: Regular consumption can help lower bad cholesterol and blood pressure, promoting better cardiovascular function.
Supports Hair Growth: Topical application of onion and lemon juice can promote hair growth due to sulfur content and improved scalp circulation.
Improves Skin: The antibacterial and antioxidant properties can help reduce acne, fade scars, and brighten skin.
Anti-inflammatory Effects: Powerful flavonoids like quercetin and sulfur compounds reduce inflammation throughout the body.
Potential Side Effects: Consuming high amounts of raw onion may cause digestive distress, and topical use can lead to skin irritation.

A Powerful Duo of Nutrients

Both onion and lemon juice are celebrated for their individual health benefits, but together, their properties can be synergistically enhanced. Onions, a member of the allium family, are packed with sulfur compounds and flavonoids like quercetin, providing anti-inflammatory and antibacterial effects. Lemon juice is a well-known source of vitamin C and potent antioxidants. The vitamin C in lemon juice has been shown to enhance the body's absorption of iron and other minerals found in onions, maximizing their nutritional impact.

Internal Benefits: A Look Inside the Body

When consumed, the onion and lemon juice combination offers a wide range of systemic advantages:

Enhanced Immune Function: The high vitamin C content from lemon and the quercetin from onions work together to strengthen the immune system and neutralize harmful free radicals. Some evidence suggests this duo may help combat bacteria and viruses.
Improved Digestive Health: Onions are rich in prebiotic fibers, such as inulin and fructooligosaccharides, which feed beneficial gut bacteria. Lemon juice stimulates digestive secretions, and the combination can alleviate bloating and promote regularity. The antibacterial properties of onion can also help protect against harmful gut microbes.
Cardiovascular Support: Studies show that quercetin and sulfur compounds in onions can help lower blood pressure, reduce LDL (bad) cholesterol, and improve circulation. Lemon juice also contributes to heart health by fighting free radical damage to blood vessels.
Blood Sugar Regulation: Compounds in onions, including chromium, may enhance insulin sensitivity and regulate blood sugar levels, which is beneficial for managing diabetes.
Detoxification and Anti-inflammatory Effects: This combination supports liver function, helping the body flush out toxins more efficiently. The anti-inflammatory properties of onions can reduce inflammation throughout the body, providing relief from conditions like arthritis.

External Benefits: Promoting Hair and Skin Health

Beyond internal consumption, this potent duo is also used as a natural remedy for topical applications:

Promotes Hair Growth: Onion juice is rich in dietary sulfur, a mineral crucial for the production of keratin, a key protein in hair. Applying it to the scalp can improve blood circulation to hair follicles and may help stimulate hair growth and reduce thinning.
Reverses Premature Graying: Some traditional remedies suggest that the potent antioxidants in onion juice can help reverse or slow the process of premature graying. Adding lemon juice is thought to boost this effect and add shine.
Soothes Skin Irritation: The anti-inflammatory and antibacterial properties make the combination useful for treating skin issues. It can reduce the risk of infection and soothe acne and blemishes.

Combining Onion and Lemon: Ingestion vs. Topical Application


Feature	Ingestion (Drinking Tonic/Salad)	Topical Application (Hair/Skin Mask)
Primary Benefits	Immune boost, cardiovascular support, improved digestion, blood sugar regulation.	Promotes hair growth, reverses graying, reduces dandruff, fades acne scars, brightens skin.
Mechanism	Synergistic action of antioxidants (quercetin, Vitamin C) and sulfur compounds throughout the body.	Direct application of sulfur and antioxidants to target hair follicles and skin cells.
Nutrient Delivery	Systemic, affecting overall wellness from within.	Localized, focusing on specific external areas like the scalp or skin.
Potential Risks	Digestive discomfort (gas, bloating), heartburn, bad breath.	Skin irritation, redness, potential stinging, unpleasant odor.
Preparation	Mixing fresh juice, adding to food, or making a tea.	Blending onion with lemon juice and other soothing agents like olive oil or aloe vera.

Precautions and Potential Side Effects

While generally safe in food amounts, consuming large quantities of raw onion and lemon juice can lead to side effects. The fructans in raw onions can cause gas, bloating, and other digestive issues, especially for those with sensitive stomachs or IBS. The pungent sulfur compounds can also lead to bad breath and body odor. When applied topically, pure onion juice can cause skin irritation or eczema in some individuals. It is crucial to perform a patch test before using it extensively on your skin or scalp.

Furthermore, individuals with certain conditions should be cautious. WebMD notes that onion supplements can slow blood clotting and lower blood sugar, potentially interacting with medications. Always consult a healthcare professional before using high concentrations of these ingredients for medicinal purposes, especially if you are pregnant, breastfeeding, or have a pre-existing medical condition.

Safe Ways to Incorporate Onion and Lemon Juice

For a general health tonic, try mixing a teaspoon of raw onion juice with a tablespoon of lemon juice in a glass of warm water. Add honey to improve the taste and for its soothing properties. Consume this mixture in moderation. For external use, dilute the onion-lemon juice mixture with a carrier oil like coconut or olive oil before applying it to the hair or skin, and rinse thoroughly after 30-60 minutes to avoid irritation and minimize odor. For hair, a rinse with rose water after shampooing can further help to mask the smell.

Conclusion

What does onion and lemon juice do to the body? When used judiciously, this combination can provide a range of health benefits both internally and externally. Its potent mix of antioxidants, anti-inflammatory agents, and essential nutrients makes it a valuable addition to a healthy diet and natural skincare routine. However, it is essential to be aware of potential side effects, particularly digestive issues from raw onion consumption and skin irritation from topical use. By starting with small amounts and observing your body's reaction, you can safely enjoy the positive effects this powerful duo has to offer.

Author's Note: Remember to consult with a healthcare professional before starting any new health regimen, especially if you have chronic health conditions. For more information on the health benefits of ingredients like onion, visit sites like Healthline for evidence-based insights on nutrition and wellness.

Frequently Asked Questions

Yes, in moderation, a diluted tonic of onion and lemon juice is generally safe for most people. However, excessive consumption of raw onion can cause digestive issues like gas and bloating due to fructans. It is always wise to listen to your body and start with small amounts.

Yes, onion juice, rich in sulfur, has been used as a home remedy to promote hair growth and strengthen hair follicles. Adding lemon juice can help reduce the strong smell while providing extra shine and benefits.

Topical application may help with acne, blemishes, and premature aging due to the antibacterial properties of onions and the antioxidants in lemon. It can help stimulate collagen production and promote brighter skin.

Onions are rich in prebiotics that feed good gut bacteria, while lemon juice can help stimulate digestion. Together, they can promote regularity and reduce bloating.

For some people, pure onion juice can be irritating to the skin. To minimize this risk, it's recommended to dilute the mixture with water or a carrier oil like coconut or olive oil and perform a patch test before extensive use.

While not a magic solution, the combination can support weight management. Both ingredients are low in calories, and onions' high fiber content helps you feel full longer and aids digestion.

Yes, onion juice has a strong, lingering smell. Using lemon juice helps reduce it, and rinsing with rose water or diluting with carrier oils can also help minimize the odor.

People with irritable bowel syndrome (IBS) or sensitive stomachs may experience digestive discomfort. Additionally, individuals on blood-thinning or diabetes medication should exercise caution and consult a doctor, as onion can affect blood clotting and sugar levels.