How much onion juice should I drink daily? A guide to safe consumption

October 6, 2025 •

5 min read

According to some studies, a daily intake equivalent to 50-70 grams of fresh onion may offer health benefits like reduced bone loss and strengthened bones. However, the optimal daily amount of onion juice and its safety depend heavily on individual tolerance and health conditions, warranting a closer look at the risks and rewards before making it a regular part of your routine.

Quick Summary

This guide examines the recommended daily intake for onion juice, exploring its potential health benefits for the heart, bones, and digestion while outlining the risks and side effects associated with overconsumption.

Key Points

Start Small: Begin with a very small amount, like a tablespoon, to test your tolerance before increasing intake.
Moderation is Key: Excessive consumption can lead to digestive issues, bloating, gas, and heartburn.
Consider Cooked Onions: If raw onion juice causes discomfort, cooked onion water may be easier on the stomach while still providing benefits.
Consult a Doctor: Speak with a healthcare provider before starting, especially if you have pre-existing conditions, are on medication, or are pregnant.
Nutrient Rich: Onion juice is packed with antioxidants, vitamins, and minerals that support heart, bone, and immune health.
Topical vs. Internal Use: While often used for hair, drinking onion juice has different considerations and potential side effects.
Watch for Interactions: Be aware of potential interactions with blood-thinning or diabetes medication.

While there's no official recommended daily allowance for onion juice, consuming a small, moderate amount is generally considered safe for most healthy adults, provided they don't experience side effects. Some health-related suggestions often refer to the equivalent of consuming about half to one whole medium-sized onion per day, which translates to a few tablespoons of freshly prepared juice. For example, one study found that healthy adults who drank 3 ounces (about 90 ml) of onion juice daily for eight weeks saw improved bone density. The key is to start small, observe your body's reaction, and always prioritize individual tolerance over a specific quantity. Because onion juice is a concentrated source of compounds, it can be more potent than whole onions and may cause more noticeable effects.

Potential Health Benefits of Onion Juice

Onion juice is a concentrated source of the nutrients and beneficial compounds found in onions, offering several potential health advantages when consumed in moderation. These benefits are mainly attributed to its rich antioxidant content and the presence of sulfur compounds.

Cardiovascular and Bone Health

Supports Heart Health: Onions contain flavonoids, especially quercetin, and sulfur compounds that may help lower triglycerides, cholesterol, and blood pressure. These effects contribute to improved blood vessel flexibility and reduce the risk of blood clots, promoting overall heart health.
Strengthens Bones: The antioxidants in onions may help reduce bone loss and protect against osteoporosis. A study on postmenopausal women noted stronger bones after drinking onion juice daily, possibly due to minimized cellular stress.

Digestive and Immune Function

Aids Digestion: Onions are rich in prebiotics, such as fructans and inulin, which feed beneficial bacteria in the gut. This can improve gut microbiome health, aid digestion, and potentially alleviate issues like bloating and constipation.
Boosts Immunity: The antioxidants and anti-inflammatory properties of onions, including Vitamin C and quercetin, can strengthen the immune system and help the body fight infections more effectively.

Risks and Considerations for Consumption

Despite its benefits, drinking onion juice, particularly in large quantities, comes with several risks and side effects. For many, moderation is the key to avoiding these negative outcomes.

Digestive Distress and Other Common Side Effects

Digestive Upset: The fructans in raw onions can be difficult to digest for some individuals, especially those with irritable bowel syndrome (IBS). This can lead to increased gas, bloating, stomach cramps, and diarrhea.
Bad Breath and Body Odor: The sulfur compounds responsible for the pungent odor of onions can lead to bad breath and body odor after consumption.
Heartburn and Reflux: Raw onions may relax the lower esophageal sphincter, increasing the risk of acid reflux and heartburn in susceptible individuals.

Potential Drug Interactions and Risks

Blood Thinning Properties: Compounds in onions may have mild blood-thinning effects. If you are already taking anticoagulant medication, excessive consumption could increase the risk of bleeding. It's advised to stop using medicinal amounts of onion at least two weeks before scheduled surgery.
Blood Sugar Regulation: Onions may lower blood sugar levels. Diabetics on medication should monitor their blood sugar closely when consuming medicinal amounts of onion or onion juice to prevent hypoglycemia.
Allergic Reactions: Though rare, people with allergies to mugwort or celery may also be sensitive to onions. Symptoms can include skin itching, rashes, or, in severe cases, anaphylaxis.

Comparison of Raw Onion Juice vs. Cooked Onion Water

When considering how to consume onion, the method of preparation can impact nutrient retention, taste, and digestive effects. Raw onion juice is often more potent but can be harsher on the stomach, while cooked onion water is milder.


Feature	Raw Onion Juice	Cooked Onion Water
Nutrient Content	Higher levels of sulfur compounds and Vitamin C, but can be less stable and may oxidize quickly.	Lower levels of heat-sensitive compounds; some nutrients may be lost in boiling.
Taste and Potency	Strong, pungent flavor and aroma.	Milder, more subtle onion flavor.
Digestive Impact	Can cause more significant digestive issues like gas, bloating, and heartburn, especially in sensitive individuals.	Generally easier to digest than raw juice, reducing the likelihood of gastrointestinal upset.
Preparation	Requires a blender or grater and a strainer; juice can be stored for a few days in the fridge.	Involves boiling chopped onions and straining the water.
Best For	Hair treatments (mixed with other ingredients), or for individuals with a strong stomach and high tolerance.	Soothing sore throats, congestion, and for those who find raw onions irritating.

Conclusion: Practice Moderation and Prioritize Safety

In conclusion, while onion juice offers a range of potential health benefits, there is no one-size-fits-all answer to the question of how much you should drink daily. The most prudent approach is to start with a very small amount—just a tablespoon or two—to assess your personal tolerance before gradually increasing your intake. For many, consuming the equivalent of half to one medium onion daily is a reasonable target. However, individuals with sensitive digestive systems, allergies, or those on certain medications should exercise particular caution. Always listen to your body and its signals. For the most tailored and safest advice, especially if you have an existing health condition or are pregnant, consult a healthcare professional. Incorporating onion's benefits through cooked food is often a safer, gentler alternative for those who find raw juice too harsh on their system. For general health advice, a reputable source like WebMD provides helpful information regarding onion consumption.

How to Make Onion Juice at Home

Peel and Chop: Take 1-2 medium onions, peel them, and chop them into manageable chunks.
Blend or Grate: Use a blender to process the onion chunks until a thick pulp is formed, adding a little water if needed. Alternatively, grate the onion with a microplane or box grater.
Strain the Juice: Place the onion pulp in a cheesecloth or a fine-mesh strainer over a bowl. Squeeze firmly to extract all the liquid.
Optional Flavoring: To improve the taste, mix in a little honey or a squeeze of lemon juice.

Remember to store freshly made juice in an airtight glass container in the refrigerator and use it within a few days for optimal freshness and safety.

Frequently Asked Questions

The main health benefits of drinking onion juice include its antioxidant and anti-inflammatory properties, which can support heart health by lowering cholesterol and blood pressure, aid digestion by providing prebiotics, and potentially strengthen bones.

Yes, drinking too much onion juice can be dangerous. Excessive consumption can cause significant digestive distress, including gas, bloating, and cramps, and may interfere with medications for conditions like diabetes and bleeding disorders.

You can reduce the strong smell of onion juice by mixing it with other ingredients like honey or lemon juice. Some people also add essential oils for topical use, but this is not recommended for consumption.

Raw onion juice retains more of its heat-sensitive compounds and potency, but it can also be harsher on the digestive system. Cooked onion water is milder and easier to digest, making it a better option for those with sensitive stomachs or for a more soothing remedy for things like sore throats.

Individuals with sensitive stomachs, IBS, acid reflux, or those who have had recent surgery on their digestive tract should be cautious or avoid it. Pregnant and breastfeeding women should stick to food amounts due to a lack of safety data. People with bleeding disorders or on blood-thinning or diabetes medication should also consult a doctor before consuming.

To make onion juice, peel and chop a medium onion, then blend or grate it into a pulp. Strain the pulp through a fine sieve or cheesecloth to extract the liquid. You can mix the juice with honey or lemon to improve the taste.

While onion juice is a popular topical remedy for hair growth due to its sulfur content, its effectiveness through consumption is less clear. Drinking it is not a proven method for stimulating hair growth in the same way direct scalp application is claimed to work.