Does DMG Make You Tired? Uncovering the Link Between Dimethylglycine and Fatigue

November 23, 2025 •

5 min read

Marketed for decades as a performance enhancer and a way to reduce fatigue, DMG has been praised by some for its energy-boosting properties. However, many users report feeling paradoxically tired after starting this supplement, leading to the question: does DMG make you tired?

Quick Summary

While often promoted to boost energy, scientific evidence for DMG's anti-fatigue effects is mixed. Reasons for feeling tired may include unrelated health issues, dosage sensitivity, or supplement quality, as fatigue is not a commonly documented side effect of DMG itself.

Key Points

Marketed for Energy: DMG is often sold as a supplement to boost energy, enhance athletic performance, and combat fatigue, based on its alleged role in improving oxygen utilization.
Conflicting Research: Many human studies, including one on patients with multiple sclerosis, have found little to no evidence that DMG effectively reduces fatigue or enhances performance.
No Documented Fatigue Side Effect: Reputable sources like VCA Animal Hospitals do not list fatigue or tiredness as a known side effect of DMG supplementation.
Other Factors at Play: Fatigue experienced while taking DMG is likely caused by unrelated issues, such as poor sleep, nutritional deficiencies, stress, or underlying medical conditions.
Check Supplement Quality: Due to a lack of strict regulation, supplement quality can vary, and contaminants or inconsistent dosages may cause adverse effects.
Glycine Confusion: DMG should not be confused with glycine, a related amino acid that can cause drowsiness and improve sleep.
Consult a Doctor: If persistent fatigue occurs, it is important to consult a healthcare provider to rule out other medical causes.

The Promise of DMG: Boosts, Not Burdens

For many years, N,N-Dimethylglycine (DMG) has been promoted as a potent tool for enhancing physical and mental performance. Its purported benefits often center on energy and endurance, leading athletes and health enthusiasts to use it with the expectation of feeling more energetic and less fatigued. The proposed mechanisms behind these benefits involve several key bodily processes, such as improved oxygen utilization and enhanced mitochondrial function.

Enhanced Oxygen Utilization: Proponents suggest that DMG acts as a 'metabolic enhancer,' improving the body's ability to use oxygen more efficiently during physical activity. This can help limit the buildup of lactic acid, a byproduct of intense exercise that contributes to muscle fatigue and soreness.
Mitochondrial Support: As a precursor to phosphocreatine, a high-energy phosphate molecule, DMG supports the mitochondria—the powerhouses of the cell—in their energy-producing functions. This is particularly important during periods of high physical or mental stress.
Adaptogenic Properties: In addition to its role in cellular energy, DMG is also considered an adaptogen, helping the body manage and respond to various stressors.

The Scientific Reality: Mixed Evidence

Despite decades of use and anecdotal reports, robust scientific evidence supporting DMG's anti-fatigue claims, particularly in healthy humans, remains limited and often inconclusive.

Inconsistent Findings: While early animal studies and some athletic trials showed promising results, follow-up research in adults and children has struggled to replicate these findings.
Multiple Sclerosis Study: A one-year, double-blind, placebo-controlled trial on patients with progressive multiple sclerosis, a condition associated with significant fatigue, found no significant difference in fatigue levels between the DMG group and the placebo group.
Uncertain Efficacy: Authoritative sources like Memorial Sloan Kettering Cancer Center and WebMD note that DMG's benefits are not well-established, and its use is largely based on mixed or lacking evidence from robust clinical trials.

Potential Reasons for Fatigue While Taking DMG

Given that DMG is not commonly listed as a supplement that causes tiredness, the fatigue some people experience is likely linked to other factors. Here are several considerations:

1. Dosage and Individual Sensitivity

While generally considered safe in moderate doses, long-term safety and optimal dosage are not well-established for all individuals. Some people may have a unique sensitivity to DMG, and it is possible that either a higher-than-needed dose or the timing of the dose could lead to an unexpected drop in energy. It is always wise to consult a healthcare professional to determine an appropriate dose and to discuss any adverse effects.

2. Confusion with Glycine

DMG is a derivative of the amino acid glycine. This can be a point of confusion for some people. While DMG is promoted for energy, its precursor, glycine, is well-documented for its ability to improve sleep quality and reduce daytime sleepiness. It is possible that if a supplement contains high levels of free glycine or if the body's metabolic pathways react unexpectedly, a sedative effect could occur. However, this is not a reported side effect for DMG itself.

3. Supplement Quality and Regulation

The supplement industry is not as strictly regulated as prescription medications, which can lead to inconsistencies in product quality, dosage, and ingredient purity. Some supplements may contain unlisted ingredients or fillers, or the dosage may differ from what is stated on the label. Opting for reputable brands that provide third-party testing can help mitigate this risk.

4. Unrelated Health and Lifestyle Factors

Often, fatigue is a symptom of underlying issues completely unrelated to supplement intake. Taking DMG while experiencing fatigue from other causes could lead to a false assumption of causation. Common causes of fatigue include:

Lack of Sleep: Insufficient or poor-quality sleep is one of the most common causes of daytime fatigue.
Nutritional Deficiencies: Low levels of iron, vitamin D, or B vitamins can lead to anemia and severe tiredness.
Emotional and Mental Stress: Chronic stress, anxiety, and depression are major contributors to fatigue.
Medical Conditions: A wide range of conditions, from thyroid disorders to infections, can cause persistent fatigue.

DMG vs. TMG (Betaine): A Comparison

DMG is often confused with Trimethylglycine (TMG), also known as betaine. While both are related amino acid derivatives involved in methylation, their roles are slightly different. Understanding the distinctions can prevent confusion.


Feature	DMG (N,N-Dimethylglycine)	TMG (Trimethylglycine / Betaine)
Methyl Groups	Two	Three
Primary Role	Intermediate metabolite in the choline pathway. Supplies methyl groups for reactions.	Primary methyl donor, converting homocysteine to methionine.
Common Use	Marketed for immune support, athletic performance, and energy enhancement.	Used for heart health, athletic performance, and liver detoxification.
Side Effects	Not well-documented; generally considered safe in conventional amounts.	More commonly associated with digestive issues like diarrhea, indigestion, and bloating.
Fatigue Link	Proposed to reduce fatigue, though clinical evidence is mixed. Unlikely to cause fatigue directly.	Not typically associated with causing fatigue. Glycine (a precursor) can have sedative effects.

Conclusion

While the popular belief is that DMG should provide an energy boost, the scientific evidence supporting this is inconsistent, and there are no documented side effects listing fatigue as a consequence. Therefore, if you are asking, "Does DMG make you tired?" it is crucial to look beyond the supplement itself. The most likely culprits are other factors, such as underlying health conditions, nutritional deficiencies, or lifestyle habits. It is also possible that individual sensitivities or a lower-quality supplement could be playing a role. Before making any changes to your supplement regimen, a consultation with a healthcare provider can help you identify the true cause of your fatigue and address it effectively.

For more information on the purported benefits of DMG, you can review some of the marketing claims on platforms like DaVinci Labs, but remember to cross-reference this information with peer-reviewed scientific studies to get a complete picture.(https://blog.davincilabs.com/blog/link-between-dmg-and-athletic-performance)

Recommended Next Steps for Persistent Fatigue

If you find yourself consistently tired after starting DMG, consider the following:

Stop and Re-evaluate: Discontinue the supplement for a week or two to see if your energy levels return to normal.
Adjust Timing and Dosage: Experiment with taking DMG earlier in the day or at a lower dose.
Address Lifestyle Factors: Ensure you are getting adequate sleep, maintaining a balanced diet, and managing stress levels.
Check for Other Deficiencies: Have a doctor check for common nutritional deficiencies that cause fatigue, such as iron or vitamin B12.
Consult a Professional: A healthcare provider can help rule out any underlying medical conditions contributing to your symptoms.

Ultimately, while DMG is not a direct cause of fatigue, it is essential to be a critical consumer and address all potential factors contributing to your low energy.

Frequently Asked Questions

There is no definitive evidence to suggest that high doses of DMG directly cause fatigue. However, without extensive clinical research on the effects of varied dosages, individual sensitivities cannot be ruled out. It is always best to stick to the manufacturer's recommended dosage and consult a healthcare professional with any concerns.

Fatigue while taking DMG is more likely caused by other factors unrelated to the supplement. Common culprits include insufficient sleep, poor diet, chronic stress, or an underlying medical condition. It is possible that taking DMG masks or coincides with these other issues.

Yes, there is. DMG is a derivative of glycine, but they have different effects. While DMG is promoted for energy, glycine is known to improve sleep quality and can reduce daytime sleepiness by helping you get better rest, rather than acting as a stimulant.

Yes, inconsistencies in supplement manufacturing are a possibility. Since the supplement industry lacks stringent regulation, poor quality products, contaminants, or inaccurate dosages could potentially lead to unexpected side effects. Always choose reputable brands with third-party testing.

The duration can vary by individual. Some may feel effects within a few days, while others might notice nothing. If you experience fatigue, it is wise to discontinue it and speak with a doctor to investigate other potential causes of your tiredness.

Side effects of DMG are not well-documented in human studies. VCA Animal Hospitals states there are no documented side effects, though it notes that research is limited. WebMD lists it as "possibly safe" for short-term use, noting that long-term safety is unknown.

There are no documented drug interactions for DMG. However, many prescription and over-the-counter medications can cause fatigue, including antidepressants and antihistamines. It is important to inform your doctor about all supplements you take to assess potential interactions.