How to Reduce Trimethylamine Levels Effectively

November 16, 2025 •

4 min read

Trimethylamine (TMA) is a compound produced by gut bacteria that can cause a strong, unpleasant body odor, particularly in individuals with the genetic disorder trimethylaminuria (TMAU). Affecting millions worldwide, this condition can be managed through a multi-faceted approach focusing on diet, supplements, and personal hygiene.

Quick Summary

Management strategies focus on dietary modifications to limit precursor compounds, leveraging specific supplements, and making strategic lifestyle adjustments. These interventions help reduce TMA production in the gut and minimize its release through the body's pores.

Key Points

Dietary Control: Following a low-choline diet by limiting foods like eggs, red meat, seafood, legumes, and brassicas can effectively reduce TMA production.
Gut Microbiome Modulation: Using specific probiotic strains, like Lactobacillus rhamnosus GG, can rebalance gut bacteria and lower TMA levels.
Hygiene Management: Using pH-balanced soaps (5.5-6.5) can neutralize TMA on the skin, helping to reduce body odor.
Medical Interventions: Short courses of low-dose antibiotics can temporarily suppress TMA-producing gut flora, but should be monitored by a healthcare professional due to risks of resistance.
Supplement Support: Supplements like activated charcoal or riboflavin (Vitamin B2) may help manage symptoms by binding TMA or enhancing residual FMO3 enzyme activity.
Lifestyle Adjustments: Managing stress, avoiding excessive sweating, and wearing breathable fabrics can help minimize the release of TMA through sweat.
Professional Guidance: A dietitian can help create a nutritionally balanced low-choline meal plan, which is especially important for pregnant women and children.

Understanding Trimethylamine (TMA) and Its Production

Trimethylamine is a metabolic byproduct of gut bacteria that can create a fishy odor in bodily fluids like sweat, breath, and urine. While the human body typically converts TMA into a non-odorous form (trimethylamine N-oxide) using the flavin-containing monooxygenase 3 (FMO3) enzyme, a deficiency or dysfunction in this enzyme can lead to TMA accumulation. This can be due to genetic factors (primary trimethylaminuria) or other conditions like liver disease or an unbalanced gut microbiome (secondary trimethylaminuria). The primary source of TMA comes from dietary precursors, including choline, L-carnitine, and trimethylamine N-oxide (TMAO), found predominantly in animal products.

Targeting Your Diet to Reduce TMA Precursors

Dietary management is one of the most critical steps in controlling trimethylamine levels. A low-choline diet can significantly reduce the amount of precursor material available to gut bacteria for conversion into TMA. While a completely choline-free diet is neither possible nor healthy, reducing intake of high-choline foods is key. Consulting a dietitian is crucial to ensure nutritional needs are met, especially for pregnant women, infants, and young children, who require adequate choline for brain development.

Here are the foods to limit or avoid:

Seafood: Saltwater fish, crustaceans (crab, lobster), and cephalopods contain high levels of TMAO and should be completely avoided. Freshwater fish have much lower levels and may be tolerated.
High-choline animal products: This includes egg yolks, liver, kidney, and other offal. Some red meat is also high in L-carnitine, another TMA precursor.
Legumes and soy products: Peas, beans, peanuts, and various soy products like tofu are high in choline and should be limited.
Brassicas: Cruciferous vegetables such as broccoli, cauliflower, cabbage, and Brussels sprouts contain compounds that may inhibit the FMO3 enzyme, potentially exacerbating the condition.
Certain dairy: Milk from wheat-fed cows has been identified as having high TMA content and should be avoided.
Supplements: Avoid supplements containing lecithin, choline, and carnitine.

Supporting Your Gut Microbiome

Modulating your gut microbiome can play a vital role in reducing TMA production. Some strategies involve using antibiotics and probiotics, though long-term use requires careful monitoring and guidance from a healthcare provider.

Probiotics: Specific probiotic strains, particularly certain strains of Lactobacillus and Bifidobacterium, have shown promise in rebalancing gut flora to produce less TMA. However, the effect is strain-specific, so not all probiotic products will be effective.
Antibiotics: In some cases, short courses of low-dose antibiotics can be prescribed to reduce the population of TMA-producing gut bacteria. This is generally used for temporary relief or in severe cases due to the risk of resistance.
Fiber intake: Increasing your fiber intake promotes the growth of beneficial gut bacteria that may reduce TMA production. A balanced, plant-rich diet can be helpful.

Comparison of Treatment Options for Reducing Trimethylamine


Treatment Strategy	Mechanism of Action	Pros	Cons	Effectiveness for TMA Reduction
Low-Choline Diet	Reduces the intake of TMA precursor nutrients.	Safe, natural, and highly effective for most individuals.	Can lead to nutrient deficiencies if not properly managed. Requires long-term adherence.	High
Oral Antibiotics	Temporarily suppresses TMA-producing gut bacteria.	Provides rapid, short-term relief from symptoms.	Risk of antibiotic resistance and microbiome disruption with long-term use.	Moderate to High (short-term)
Activated Charcoal	Binds to TMA in the gut, preventing its absorption.	Non-invasive and can offer temporary relief.	Effectiveness varies; can bind other medications and nutrients.	Variable
Riboflavin (B2) Supplements	Enhances the residual activity of the FMO3 enzyme.	Can improve symptom control for those with mild deficiencies.	Not effective for everyone, especially those with severe FMO3 genetic mutations.	Variable
Probiotics	Rebalances gut microbiota to favor less TMA production.	Supports overall gut health and provides a sustainable solution.	Effect is strain-specific and can be inconsistent. Takes time to see results.	Variable to Moderate
pH-Balanced Soaps	Reduces the volatility of TMA on the skin's surface.	Addresses external odor, providing quick symptom management.	Does not address the root cause of TMA production.	High (for topical odor)

Lifestyle Adjustments and Personal Hygiene

Beyond diet and medical interventions, several lifestyle changes can help reduce trimethylamine odor.

Use pH-balanced soaps: Since TMA is a strong base, using soaps with a slightly acidic pH (5.5-6.5) can help neutralize the chemical on the skin's surface, making it less volatile and less odorous.
Manage stress and exercise: Stress and vigorous physical exercise can increase sweating, which may exacerbate the odor. While exercise should not be avoided, adopting stress management techniques and wearing breathable fabrics can help.
Stay hydrated: Drinking plenty of water supports kidney function and may assist in flushing out TMA.

Conclusion

Reducing trimethylamine effectively involves a holistic strategy that addresses both the internal production and external management of its effects. By focusing on a low-choline diet, supporting a healthy gut microbiome with probiotics, and making strategic lifestyle and hygiene adjustments, individuals can significantly control TMA levels and improve their quality of life. Medical guidance is essential, especially when considering nutritional changes, supplements, or medications, to ensure the approach is safe and effective for your specific needs. Realizing that the problem is a medical condition and not a personal failing can be a powerful first step toward successful management.

Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new treatment or dietary regimen, especially for diagnosed conditions like trimethylaminuria.

Frequently Asked Questions

To reduce trimethylamine, you should limit or avoid foods high in its precursors, including saltwater fish, crustaceans, eggs (especially yolks), liver, kidney, peas, beans, peanuts, soy products, milk from wheat-fed cows, and cruciferous vegetables like broccoli and cauliflower.

Yes, some studies suggest that specific probiotic strains, particularly Lactobacillus rhamnosus GG and certain Bifidobacterium strains, can help modulate the gut microbiome to reduce TMA production. The effectiveness, however, is strain-specific and may vary by individual.

To manage the body odor, use soaps with a slightly acidic pH (5.5-6.5) to neutralize TMA on the skin. Frequent washing, especially after sweating, can also help. Wearing breathable fabrics and managing stress can reduce sweating and minimize odor.

Activated charcoal has been reported to help reduce TMA levels in the gut by binding to the compound. It can offer temporary relief, but its effectiveness can vary among individuals and it may interfere with the absorption of other medications.

Besides activated charcoal, supplements like copper chlorophyllin and riboflavin (Vitamin B2) have been explored. Riboflavin can enhance the activity of the FMO3 enzyme, while copper chlorophyllin may help neutralize odor.

Yes, it is important to consult a healthcare provider for diagnosis and management. They can confirm the cause, rule out other conditions, and help you develop a safe and effective treatment plan that may include dietary changes, supplements, or medication.

Primary trimethylaminuria is a genetic disorder caused by mutations in the FMO3 gene. Secondary trimethylaminuria is acquired later in life due to liver conditions, an imbalanced gut microbiome, or precursor overload from supplements like choline or carnitine.