What are the side effects of too much lemongrass?

December 15, 2025 •

4 min read

While typically enjoyed for its citrusy aroma and health benefits, excessive lemongrass consumption has been shown to cause adverse effects. These can range from mild digestive discomfort to more serious complications, particularly for those with pre-existing conditions. Understanding what are the side effects of too much lemongrass is crucial for safe and responsible use.

Quick Summary

Excessive intake of lemongrass, particularly in concentrated forms like supplements or potent teas, can lead to side effects. Common issues include gastrointestinal upset, increased urination, dizziness, fatigue, and potential allergic reactions. High doses can affect kidney function and interact with certain medications.

Key Points

Gastrointestinal Distress: Consuming excessive lemongrass can lead to stomach upset, including nausea, vomiting, cramps, and diarrhea due to its potent compounds.
Kidney and Liver Damage: Very high or prolonged doses of lemongrass, particularly concentrated essential oil or strong teas, have been linked to potential harm to kidney and liver function.
Neurological Side Effects: Large amounts can cause dizziness, fatigue, and drowsiness, stemming from its mild sedative effects.
Allergic Reactions: Though uncommon, some individuals may experience allergic reactions such as skin rashes, itching, or respiratory symptoms from either topical or oral exposure to lemongrass.
Drug Interactions: Lemongrass can interact with medications for diabetes, high blood pressure, and blood thinners, potentially amplifying their effects.
Fluid Imbalance: As a diuretic, excessive lemongrass intake can cause frequent urination, possibly leading to dehydration and dry mouth.
Pregnancy and Breastfeeding Risk: Due to its potential to stimulate menstrual flow and other risks, lemongrass should be avoided in large amounts by pregnant and breastfeeding women.

Lemongrass (Cymbopogon citratus) is a versatile herb widely celebrated for its culinary applications and medicinal properties, from aiding digestion to possessing anti-inflammatory and antioxidant qualities. However, as with many natural remedies, moderation is key. Consuming too much lemongrass can transition from beneficial to harmful, triggering a range of adverse effects that users should be aware of. Understanding these potential risks is the first step toward safe herbal consumption.

Digestive Distress and Gastrointestinal Issues

One of the most common consequences of overdoing lemongrass is gastrointestinal upset. The herb's potent compounds, while helpful in small amounts, can irritate the stomach lining when consumed in excess. This can result in a number of unpleasant symptoms:

Nausea and vomiting: Large quantities of lemongrass can trigger a nauseous feeling, and in more severe cases, cause vomiting.
Stomach cramps and pain: High concentrations may lead to painful stomach cramps or a general feeling of discomfort.
Diarrhea or constipation: The high fiber content in some forms of lemongrass can disrupt normal bowel function, leading to either loose stools or constipation.

Impact on Kidney and Liver Function

Research, particularly regarding high-dose teas and essential oils, suggests a link between excessive lemongrass and potential kidney and liver damage. A human study indicated that a daily intake of 8 grams of lemongrass leaves for 30 days led to adverse effects on kidney function, including a reduction in creatinine clearance rate and estimated glomerular filtration rate. The concentrated citral and myrcene compounds in lemongrass essential oil can be cytotoxic to cells at high doses, emphasizing the need for caution, particularly with supplements.

Neurological and Systemic Effects

Beyond the digestive system, an overconsumption of lemongrass can lead to a variety of systemic and neurological symptoms. These are often linked to the herb's natural sedative properties, which can become overwhelming in large doses.

Dizziness and tiredness: The mild sedative effect can cause increased drowsiness, dizziness, and overall fatigue, making it unsafe to operate machinery.
Dry mouth and increased urination: Lemongrass acts as a diuretic, leading to more frequent urination. This can cause dehydration, which in turn leads to a dry mouth.
Increased appetite: Some reports indicate that excessive lemongrass intake can cause a significant increase in hunger, though the mechanism is not fully understood.

Allergic and Sensitivity Reactions

Although not a common allergen, allergic and sensitivity reactions to lemongrass can occur. These reactions may affect the skin, respiratory system, or digestive tract.

Skin rash and itching: Direct contact with lemongrass essential oil, especially undiluted, can cause allergic contact dermatitis, resulting in rashes, redness, and itching. Some individuals may even experience a delayed skin rash from oral consumption.
Respiratory distress: In sensitive individuals, allergic reactions can manifest as respiratory issues, including sneezing, coughing, or difficulty breathing.

Drug Interactions and Contraindications

Lemongrass can interfere with certain medications and should be used cautiously by individuals with specific health conditions.

Antihypertensive and Antidiabetic Medications: As lemongrass can naturally lower blood pressure and blood sugar, consuming it excessively while on medication for these conditions could lead to dangerously low levels (hypotension and hypoglycemia).
Blood Thinners (Anticoagulants): There is evidence suggesting lemongrass has blood-thinning properties. Large doses could increase the risk of bleeding in those taking anticoagulants like warfarin.
Glutathione-S-Transferase (GST) and CYP450 Substrates: Lemongrass compounds like citral and beta-myrcene can interfere with liver enzymes responsible for breaking down many drugs. This can alter the medication's effects and side effects.

Safe Usage: Moderation is Paramount

The key to avoiding the negative consequences of too much lemongrass is to use it in moderation and be mindful of your body's reactions. Most side effects are associated with excessive or high-dose consumption, especially from concentrated forms like supplements and undiluted essential oils. For most people, consuming lemongrass in typical culinary amounts, or as a single cup of tea, is perfectly safe. However, individuals with pre-existing conditions or those on medication should always consult a healthcare professional before incorporating it regularly into their diet.

Comparison: Moderate vs. Excessive Lemongrass Consumption


Feature	Moderate Consumption (e.g., in cooking or 1-2 cups of tea)	Excessive Consumption (e.g., high-dose supplements, prolonged intake)
Digestive System	Aids digestion, reduces bloating and gas.	Causes gastrointestinal issues, nausea, stomach pain, diarrhea, or constipation.
Kidney/Liver Health	Generally safe; no known risk at moderate culinary levels.	Potential for adverse effects on kidney function with high, prolonged doses. Can damage liver mucosa.
Energy/Alertness	Can have a mild, relaxing effect.	Leads to dizziness, drowsiness, and fatigue.
Fluid Balance	Promotes healthy fluid balance due to mild diuretic effect.	Can cause excessive urination, leading to dehydration and dry mouth.
Blood Parameters	May help manage blood sugar and cholesterol levels.	Can dangerously lower blood sugar and pressure, especially with medications.

Conclusion: Responsible Enjoyment is Key

Lemongrass is a safe and beneficial herb when used responsibly. Its numerous health advantages, from improving digestion to providing antioxidants, make it a valuable addition to both food and drink. However, the key takeaway is that more is not always better. The side effects of too much lemongrass can range from inconvenient to genuinely harmful, particularly for vulnerable populations like pregnant women or those with kidney issues. By sticking to moderate amounts and consulting a healthcare provider if you have any concerns, you can safely enjoy all that this aromatic herb has to offer.

Frequently Asked Questions

While generally safe in moderation, most sources suggest limiting intake to 1–2 cups of lemongrass tea per day. Exceeding this amount, especially for prolonged periods, increases the risk of side effects like digestive upset and potential kidney issues.

The initial signs of excessive lemongrass consumption often include mild digestive issues, such as nausea or an upset stomach. Other early symptoms might involve feeling unusually tired, dizzy, or experiencing a dry mouth due to its diuretic properties.

Yes, ingesting high doses of lemongrass essential oil can be toxic and may damage the liver and stomach mucous membranes. Essential oils are highly concentrated and should be used with extreme caution, and never ingested without professional medical guidance. For aromatherapy, follow recommended dosages.

Large amounts of lemongrass should be avoided by pregnant and breastfeeding women, individuals with pre-existing kidney or liver problems, those on blood pressure or diabetes medication, and people taking blood-thinning medications.

If you experience an allergic reaction, stop using lemongrass immediately and seek medical attention. Symptoms can include skin rashes, itching, hives, and respiratory distress.

Yes, lemongrass can interact with medications for high blood pressure, diabetes, and blood thinners. It can also interfere with liver enzymes responsible for processing certain drugs. Always consult a doctor if you are on medication before consuming large amounts of lemongrass.

Using lemongrass in cooking is generally safer than consuming high-dose teas or supplements, as the quantity used is typically much smaller. Culinary use is considered safe for most people, but caution is still advised for sensitive individuals.