What Should You Not Take With Glutamine?

October 15, 2025 •

4 min read

Research shows glutamine supplements are generally considered safe for healthy individuals, but certain medications, medical conditions, and other supplements can cause dangerous interactions. Understanding what should you not take with glutamine is crucial for preventing unwanted side effects and ensuring the supplement works effectively.

Quick Summary

Key interactions to avoid involve anticonvulsants, lactulose, and certain chemotherapy drugs. Exercise caution with alcohol, protein-heavy drinks, hot liquids, and highly acidic beverages. Individuals with liver or kidney disease, bipolar disorder, epilepsy, and MSG sensitivity should be especially careful or avoid glutamine entirely.

Key Points

Avoid Anticonvulsants: Glutamine can interfere with anti-seizure medications by increasing brain glutamate levels, potentially decreasing their effectiveness.
Do Not Take with Liver or Kidney Disease: Those with advanced liver or kidney conditions, like cirrhosis or end-stage renal failure, should avoid glutamine due to impaired ammonia metabolism.
Separate from Protein Shakes: For best absorption, avoid mixing glutamine powder with protein-heavy shakes, as amino acids can compete for uptake in the gut.
Never Mix with Hot Liquids: Heat can denature the amino acid, so mix glutamine powder with cool or room-temperature liquids only.
Use Caution with Bipolar Disorder: High doses of glutamine have been linked to potential manic episodes in individuals with bipolar disorder.
Consult Doctor for Cancer or Diabetes: Individuals undergoing chemotherapy or managing diabetes must consult a healthcare provider before taking glutamine, as it can affect treatment or blood sugar levels.
Precautionary Use in Pregnancy: Due to insufficient safety data, pregnant and breastfeeding women are advised to avoid glutamine supplementation.

Understanding glutamine interactions for safe supplementation

Glutamine is the most abundant amino acid in the body, playing a vital role in immune function, intestinal health, and muscle recovery. While many people use glutamine supplements safely, potential interactions with other substances and pre-existing medical conditions exist. By understanding these risks, you can take informed steps to protect your health.

Medications that interact with glutamine

Glutamine is primarily metabolized in the liver and kidneys and acts as a precursor to other substances, including the neurotransmitter glutamate. This metabolic pathway creates several significant drug interactions that require caution or avoidance.

Anticonvulsant medications: Glutamine may reduce the effectiveness of seizure-preventing drugs like phenobarbital and valproic acid. It can potentially increase the risk of seizures due to its conversion to glutamate in the brain. Consult a healthcare provider before taking glutamine if you have epilepsy.
Lactulose: Taking glutamine with this medication, used for high ammonia levels in liver disease, can decrease its effectiveness.
Insulin and diabetes medications: Glutamine can influence blood sugar levels, potentially altering the dosage requirements for diabetes medication. Blood glucose should be monitored by a doctor if taking glutamine.
Certain chemotherapy drugs: While glutamine may help with some chemotherapy side effects, laboratory studies suggest it could potentially stimulate tumor growth. Glutamine supplementation during cancer treatment should only be done under strict medical supervision.

Supplements, foods, and other factors to avoid

Beyond prescription drugs, several other factors can impact glutamine's efficacy and safety.

Protein-rich shakes: High amounts of other amino acids in protein shakes may compete with glutamine for absorption. Taking glutamine separately from protein-rich meals or shakes is recommended for optimal absorption.
Hot liquids or food: Avoid mixing glutamine powder with hot liquids or food, as high temperatures can degrade the amino acid. Cold or room-temperature beverages are preferable.
Highly acidic liquids: Like high heat, very acidic liquids can also degrade amino acids.
Alcohol: Excessive alcohol may interfere with glutamine metabolism and increase the risk of side effects. It's advisable to limit or avoid alcohol.
Monosodium Glutamate (MSG) sensitivity: Individuals sensitive to MSG may also react to glutamine, as it can be converted to glutamate in the body. Use caution if you have MSG sensitivity.

Who should avoid glutamine due to underlying health conditions?

Certain pre-existing conditions increase the risk of serious complications with glutamine supplementation.

Liver disease: Those with advanced liver disease should avoid glutamine. The liver's inability to metabolize glutamine can lead to a dangerous buildup of ammonia.
Kidney disease: Individuals with severe kidney disease should also avoid glutamine as their kidneys may not be able to process the extra metabolic load, potentially causing damage.
Bipolar disorder: High doses of L-glutamine may trigger manic episodes in individuals with bipolar disorder. Avoid or use only under strict medical supervision.
Reye's syndrome: Glutamine is not recommended for this condition due to the risk of worsening ammonia buildup.
Pregnancy and breastfeeding: Due to limited research, glutamine supplements are not recommended for pregnant or breastfeeding women.

Comparison of glutamine interactions

Below is a summary of key interactions:


Factor	What to Avoid	Why to Avoid
Medications	Anticonvulsants	May decrease effectiveness by increasing brain glutamate.
	Lactulose	Reduces therapeutic effect.
	Certain chemotherapy agents	Potential to stimulate tumor growth.
Supplements	Protein-heavy formulas	Competition for intestinal absorption.
	High dose Arginine	Combined effects not fully understood.
Consumption Habits	Hot beverages	Heat can degrade the amino acid.
	Highly acidic liquids	Can cause degradation.
	Excessive alcohol	Interferes with metabolism and increases side effects.
Health Conditions	Advanced liver or kidney disease	Impaired metabolism leads to toxic ammonia buildup.
	Bipolar disorder	May trigger manic episodes.
	Epilepsy/Seizure history	Risk of decreasing medication effectiveness.
	Reye's syndrome	Worsens ammonia buildup.

Navigating supplementation safely

Consult a healthcare professional before taking glutamine if you have any health conditions or take medications. Start with a low dose and avoid excessive long-term use without supervision. Mix glutamine powder with cool or room-temperature liquids to maintain its integrity and consider taking it separately from large protein meals for better absorption. Taking these precautions can help you safely explore glutamine's potential benefits.

For more detailed information on drug interactions, consult a pharmacy database or a healthcare professional.

Conclusion

While L-glutamine is generally safe for healthy individuals, awareness of potential interactions is vital. Avoid taking it with anticonvulsants, lactulose, or certain chemotherapy drugs. Do not mix glutamine powder with hot or highly acidic liquids, and consider timing its intake away from large protein meals. Individuals with severe liver or kidney disease, bipolar disorder, epilepsy, Reye's syndrome, and pregnant or breastfeeding women should avoid supplementation. Always consult a healthcare professional to ensure safe use based on your individual health profile and to discuss potential interactions.

Frequently Asked Questions

Yes, you can typically take glutamine with a pre-workout. Many pre-workout supplements already contain glutamine, but if yours does not, taking them together is generally safe. For optimal results, ensure your pre-workout isn't overly hot, as heat can degrade glutamine.

Taking glutamine on an empty stomach, or at least 1-2 hours away from a large protein meal, can maximize its absorption and effectiveness, especially for gut health benefits.

While short-term use of standard dosages is considered safe, the long-term effects of glutamine supplementation, especially at high doses, are not fully understood. It's best to consult a healthcare provider for extended use to monitor any potential metabolic changes.

For healthy individuals, glutamine is generally safe, but individuals with pre-existing liver or kidney disease should not take it. The body's inability to properly metabolize excess glutamine in these conditions can lead to a dangerous buildup of ammonia.

Yes, excessive alcohol consumption is not recommended with glutamine supplementation. Alcohol can interfere with glutamine metabolism and potentially increase the risk of side effects.

Mild side effects from high doses may include nausea, bloating, abdominal pain, and dizziness. In rare cases or with specific conditions, severe side effects like seizures or manic episodes may occur. If you experience serious symptoms, stop use and contact a doctor immediately.

Individuals sensitive to MSG should be cautious with glutamine, as the body converts it into glutamate, which is chemically related to MSG. It's recommended to start with a very low dose or avoid it entirely if sensitive.