Supplements for Energy and Concentration: when Do They Really Help?

A few Words about Supplements for Energy and Concentration

In everyday life, many people look for ways to boost their energy and concentration – either to meet work demands or to improve their performance. Easy access to dietary supplements that promise more “vitality” or better mental performance has made these products particularly popular today.

However, the truth is that fatigue and lack of concentration don’t always have the same cause.

They can be due to lack of sleep, poor diet, inadequate hydration, or chronic stress, as well as deficiencies in nutrients like iron and vitamin B12. In any case, the question remains: can supplements really help?

In this article, based on scientific data, we will examine which supplements appear to have documented benefits for energy and concentration, when they are useful, and what limitations or risks they may pose.

The Main Causes of Fatigue and Lack of Concentration

Fatigue and reduced concentration are symptoms that can affect everyone, but their causes vary.

They are often due to lifestyle-related factors or underlying medical conditions such as:

• Insufficient sleep

Sleep is a fundamental pillar for physical and mental recovery. Poor sleep significantly affects memory, concentration, and energy levels. In fact, research shows that even a single night of insufficient sleep can lead to a noticeable decrease in performance during mentally demanding activities. [1]

• Poor diet

The quality of diet plays a crucial role in energy levels and cognitive function. A diet poor in fruits, vegetables, and whole grains deprives the body of the essential nutrients and “fuel” that the brain and muscles need to function efficiently.

Furthermore, a diet based on ultra-processed foods, rich in added sugars, leads to sharp fluctuations in blood glucose levels. This disrupted glycemic control is associated with feelings of fatigue, drowsiness, and difficulty concentrating after meals.

Conversely, consuming foods rich in fiber, protein, and “good” fats ensures a more stable release of energy, contributing to sustained alertness and mental performance.

• Inadequate hydration

Water is an essential component for brain function. The brain, compared to the other organs in our body, has the highest water content, with 75% of the brain consisting of water.

By consuming sufficient water, we maintain optimal blood flow and oxygenation to the brain, which contributes to improved cognitive skills and the prevention of mental fatigue.

Several studies have linked dehydration to impaired cognitive functions, such as attention, memory, and concentration. More specifically, research shows that a fluid loss of just 2% of body weight can negatively affect cognitive skills, including concentration, reaction time, short-term memory, and mood changes. [2]

• Nutrient deficiencies

The lack of specific nutrients is linked to fatigue and reduced concentration. These include:

• Iron: Low levels can cause fatigue, reduced endurance, and concentration disorders, even without overt anemia.
• Vitamin B12 and folic acid: Crucial for nervous system function and neurotransmitter synthesis. Deficiency is associated with memory and cognitive function problems.
• Vitamin D: Linked to mood and energy regulation. Low levels are often associated with feelings of fatigue.
• Chronic stress

When the body is exposed to prolonged stress, the hypothalamic-pituitary-adrenal (HPA) axis is continuously activated, leading to increased cortisol production.

Although cortisol is essential for immediate adaptation to stressful situations, prolonged high levels have negative consequences. Cognitively, brain areas related to memory, learning, and concentration are affected. The result is reduced mental clarity, a feeling of exhaustion, and often difficulty managing daily demands.

At the same time, chronic activation of the stress axis can burden the immune system and intensify feelings of fatigue, creating a vicious cycle of mental and physical strain.

• Underlying medical conditions

Conditions such as hypothyroidism, diabetes mellitus, or depression often manifest with persistent fatigue and reduced mental performance.

It is therefore clear that fatigue and reduced concentration do not have a single cause. Before turning to supplements, it is important to investigate the real reason behind the symptoms through a comprehensive lifestyle assessment and – when necessary – through medical examinations.

Popular Supplements for Energy and Concentration – What Science Says

Various dietary supplements are available commercially, promising more energy and mental clarity. However, the scientific evidence for their effectiveness varies significantly from product to product. Let’s look at the most commonly used ones:

Caffeine

Caffeine is perhaps the most well-known and well-studied natural stimulant. Caffeine acts by inhibiting adenosine – the chemical that makes us feel sleepy – thereby increasing alertness and reducing feelings of fatigue. It also improves reaction time, attention, and performance in demanding tasks.

However, excessive caffeine consumption is associated with insomnia, tachycardia, anxiety, and gastrointestinal disorders.

The effective and safe dose for most adults ranges from 100–200 mg, which is approximately 1–2 cups of coffee.

B Vitamins

B vitamins (B1, B2, B6, B12, folic acid, etc.) are essential for metabolism and nervous system function.

Taking multivitamin supplements can help individuals with nutritional deficiencies or increased needs (e.g., women during pregnancy or people adopting a vegan diet).

However, in healthy individuals who follow a healthy and balanced diet, taking such supplements does not appear to further improve performance or energy levels.

Iron and Vitamin B12

Iron is essential for oxygen transport to tissues, while vitamin B12 is crucial for nervous system function, contributing to the myelination of nerve fibers and neurotransmitter synthesis.

In cases of deficiency (e.g., iron deficiency anemia or B12 deficiency), supplements are indispensable, and restoring levels significantly improves fatigue and concentration. Conversely, taking them without indication or medical supervision offers no benefit and can be harmful (e.g., iron overload).

Omega-3 Fatty Acids (EPA, DHA)

Omega-3 fatty acids are structural components of brain cell membranes and contribute to nerve fiber function and inflammation regulation.

Studies show that adequate intake of omega-3 fatty acids can support cognitive function, mood, and concentration ability, especially in individuals with low levels or insufficient consumption of fatty fish.[3]

Ginseng and Rhodiola Rosea

These are two herbal extracts classified as “adaptogens,” meaning substances that appear to enhance the body’s ability to cope with stress and fatigue. Ginseng has been primarily studied for improving mental clarity and physical endurance, while Rhodiola is associated with reducing feelings of exhaustion during periods of prolonged pressure.[4]^,[5]

Although the findings so far are encouraging, the quality and consistency of studies vary, which is why their documentation is considered more limited compared to other, more thoroughly studied substances like caffeine.

L-Theanine

This is an amino acid found primarily in green tea, notable for its mild relaxing effect, which is not accompanied by drowsiness.

Its mechanism is related to the regulation of neurotransmitters such as GABA, dopamine, and serotonin, substances that affect mood, concentration, and mental calmness.

When combined with caffeine, it creates a synergistic combination: it enhances concentration and clarity, while simultaneously reducing symptoms of overstimulation and nervousness that caffeine alone can cause.

Potential Risks and Limitations

Although supplements can be useful in some cases, their indiscriminate or untargeted use carries risks.

Some points of caution are:

• Excessive caffeine use: Caffeine is safe in moderate doses (up to 400 mg/day for most adults), however, excessive consumption can cause insomnia, nervousness, tachycardia, gastrointestinal disorders, and in some cases, dependence. In sensitive individuals, even smaller doses are enough to cause adverse effects.
• Indiscriminate use: The use of iron, vitamin B12, or other micronutrient supplements without laboratory testing can be dangerous. For example, excessive iron consumption can lead to overload and damage to the liver and heart, while indiscriminate use of vitamins can mask other underlying causes of fatigue without addressing them.
• Interactions with medications: Some supplements affect the action of medications. Ginseng can interact with anticoagulants, Rhodiola with antidepressants, while omega-3 fatty acids in high doses may increase the risk of bleeding when combined with antiplatelet or anticoagulant therapy. Even caffeine can affect the action of certain medications.

Therefore, before taking any supplement, guidance from the treating physician or dietitian is essential to ensure both effectiveness and safety.

Practical Advice for the Public

Before turning to supplements, it’s important to remember that they are not a “quick fix” for fatigue or lack of concentration.

There are some key steps that can make a difference:

• Prioritize investigating the cause: If fatigue is frequent or prolonged, the first step should be a simple blood test and consultation with a specialist. This way, potential deficiencies (e.g., iron, B12, vitamin D) or underlying health problems can be identified, ensuring that supplementation is targeted and safe.
• Emphasize lifestyle changes: A healthy and balanced diet, adequate hydration, and quality sleep remain the “fundamental pillars” for stable energy levels and mental performance. Even the best supplement cannot replace the value of a healthy lifestyle.
• Focus on careful product selection: If supplement use is recommended, it is important to choose products from reputable companies, with quality certifications and clear dosage labeling. This reduces the risk of adulteration or incorrect dosages, which unfortunately is observed in many low-quality preparations.

In conclusion, supplements may have a place, but they are not a panacea. The substantial improvement of energy and concentration always starts with the simple and fundamental: proper nutrition, exercise, rest, and effective stress management.

Conclusion

Supplements for energy and concentration can be useful in some cases, especially when there is a confirmed nutrient deficiency or increased needs not met by diet.

However, no supplement can replace the importance of a healthy diet, exercise, quality sleep, adequate hydration, and proper stress management. Blindly taking preparations without guidance carries risks and often offers no real benefit.

The key lies in proper evaluation by a specialist, personalization, and connecting supplements – where needed – with a healthy lifestyle. This way, they can function as a useful tool and not as a disappointing “quick fix.”

References

[1] Killgore W. Effects of sleep deprivation on cognition. Prog Brain Res. 2010:185:105-29. doi: 10.1016/B978-0-444-53702-7.00007-5.

[2] Adan, A. (2012). Cognitive performance and dehydration. Journal of the American College of Nutrition, 31(2), 71-78. https://doi.org/10.1080/07315724.2012.10720011.

[3]Wan Suh S, Lim E, Burm S, Lee H, Bae J, Han J, Kim K. The influence of n-3 polyunsaturated fatty acids on cognitive function in individuals without dementia: a systematic review and dose-response meta-analysis. BMC Med. 2024, 22(1):109. doi: 10.1186/s12916-024-03296-0.

[4]Zeng M, Zhang K, Yang J, Zhang Y, You P, Yan L, Weng Y. Effects of Ginseng on Cognitive Function: A Systematic Review and Meta-Analysis. Phytother Res. 2024, 38(12):6023-6034. doi: 10.1002/ptr.8359.

[5]Anghelescu I, Edwards D, Seifritz E, Kasper S. Stress management and the role of Rhodiola rosea: a review. Int J Psychiatry Clin Pract. 2018, 22(4):242-252. doi: 10.1080/13651501.2017.1417442.