Mendi Review in 2025: Does This Brain Training Device Work?

Do you want to measure and train your brain to improve focus, mood, and mental resilience? The Mendi headband might do just that. It is a cutting-edge neurofeedback device that uses functional near-infrared spectroscopy (fNIRS) to help measure brain activity and provide real-time feedback via a game.

Read this review to learn all about Mendi. We discuss the device in depth and examine the science behind neurofeedback training.

What is Mendi, and how does it work?

Mendi is a portable neurofeedback brain training device (or system) that utilizes fNIRS technology with behavioral training (via in-app game) to measure blood flow and oxygenation within the brain's prefrontal cortex. The prefrontal cortex is an area of the brain that plays an important role in attention, concentration, and emotion regulation.

Mendi provides immediate neurofeedback based on the neural activity in the prefrontal cortex to help users gain better control over certain cognitive functions. As you train your brain through the app-based game consistently, you may learn how to self-regulate your brain activity and improve cognitive functions, including attention and focus.

Mendi stands out from the rest of the market because it is fairly affordable and does not require a separate subscription to use the app.

The device comes with a Mendi headset, a charging cable, free access to the Mendi brain app for iOS and Android devices, and a 100% money-back guarantee.

Potential benefits of Mendi

More studies are needed to confirm Mendi's suggested benefits. Since you can read the marketing claims of Mendi's benefits yourself, we look into the scientific backing behind neurofeedback.

Improved focus and attention

Neurofeedback has the potential to help with cognitive performance and boost focus, which may be particularly useful for people with ADHD. In fact, neurofeedback has been used for some time as an adjunct treatment method in addition to medication and/or behavioral therapy.

A pilot study showed that fNIRS neurofeedback can improve attention levels and that individualized training offers more benefits than non-individualized training. A meta-analysis of 15 randomized clinical trials on neurofeedback training in healthy adults found that neurofeedback improved attention significantly compared to no training but did not show significant differences compared to fake neurofeedback training.

There is also some research looking into the use of neurofeedback for managing ADHD.

A meta-analysis of randomized studies summarized that despite methodological differences, neurofeedback can reduce hyperactivity, inattention, and impulsivity to a clinically significant level. A pilot study compared 12 NIRS sessions to 12 EEG sessions for managing ADHD symptoms in children aged 7–10. The results were based on parents’ ratings and showed more significant improvements in computer-based attention tests in the NIRS group.

Despite the emerging evidence, most commercially available neurofeedback devices for at-home use have not been studied in clinical trials. Moreover, the most frequently used method in clinical trials was EEG neurofeedback, while the evidence for fNIRS neurofeedback is limited to a small number of studies.

Improved emotional regulation

By tracking the activity of oxygenated blood flow in the prefrontal cortex and providing real-time feedback to the user, Mendi is claimed to improve emotion regulation and stress management.

A meta-analysis of 51 studies found that fMRI neurofeedback can help with emotional regulation in healthy individuals. However, the effects are highly influenced by which brain regions are being targeted, what specific emotion regulation tasks are being performed, and individual factors.

A study on 26 healthy individuals with high anxiety found that fMRI neurofeedback training during threat exposure decreased anxiety, and the results were maintained after the 3-day follow-up.

While the above studies utilized fMRI neurofeedback, one study explored if fNIRS real-time neurofeedback training could help improve self-regulation. The study results show that this type of training can improve emotion regulation by enhancing activity in certain parts of the prefrontal cortex.

Overall, neurofeedback shows some potential benefits to help with emotional regulation, but the evidence is highly individual and scarce. In any case, Mendi is by no means a treatment for any mental condition.

Improved sleep

While the brand suggests Mendi may help achieve better sleep, the evidence for the utility of fNIRS neurofeedback in sleep is scarce.

A meta-analysis of 12 studies found that EEG-based neurofeedback helped improve sleep in the majority of the included studies. However, it is hard to draw conclusions due to differing protocols and the potential placebo effect.

Moreover, study results with insomnia patients have questioned the effectiveness of neurofeedback for sleep disorders, as no significant improvements in sleep were obtained with EEG neurofeedback.

There is a lack of research on using fNIRS for sleep. However, it can be used to investigate sleep quality and time spent in different stages. Mendi may be able to support sleep indirectly by providing a relaxing bedtime ritual that can cue your brain for sleep or by reducing anxiety.

How to use Mendi

Mendi comes with detailed instructions for setup. The process is pretty straightforward and can be done in any quiet place.

1. Ensure the device is fully charged and turn it on
2. Download the Mendi app
3. Put on the headset
4. Follow the instructions of the initial setup section
5. Track your progress over time

A typical session usually involves a visual game that requires mental focus and calm breathing to progress. It is normal for your mind to wander, but try to regain focus and stay calm. The goal of the overall session is to make it easier for your brain to maintain and regain concentration. After the session, you will be able to see metrics such as oxygenated blood flow in response to neural activity in your prefrontal cortex when playing the game.

A typical session is 5–10 minutes, but you can gradually build it up to 15 minutes. The manufacturer recommends 3–5 sessions weekly to build consistency and see potential improvements in focus, relaxation, and cognitive performance. Once you feel comfortable with using the device and have built up a routine, you may use it daily.

Consistent use is key to maximizing the benefits. The manufacturer also highlights the importance of mindfulness, a good sleep schedule, and exercise to reap the most benefits.

Mendi’s features and technology

Mendi uses fNIRS technology to measure changes in blood flow and oxygenation in the prefrontal cortex during tasks. The data is processed with proprietary algorithms to create visual representations of brain activation that are accessible on the app. The main goal is to measure and visualize how brain activity changes in response to engaging with an in-app game. With consistent practice, the brand suggests you may improve cognitive function, focus, stress, and emotional regulation.

The app also tracks your progress and adjusts the sessions to provide personal training. You can set goals and receive personalized feedback and real-time adjustments during your training to optimize the sessions.

One of Mendi's main benefits is its lightweight, ergonomic design and user-friendly app. The headband is compact and foldable, making it easy to take with you on the go. It is also adjustable to ensure the band sits comfortably. The sleek design and Bluetooth connectivity ensure a hassle-free experience.

However, we have to mention the limitations of fNIRS. The main drawback of technology and devices like Mendi is a lack of precision and accuracy. The data is heavily influenced by sensor location and signal processing, all of which can vary among individuals or even between sessions if you slightly alter the placement of the headband.

Side effects and safety of Mendi

Generally, fNRIS is a noninvasive technology that is considered harmless and has no reports of severe side effects. Mendi monitors blood flow and neural activity using low-intensity near-infrared light without electrical stimulation, making it suitable for most people. However, some groups should carefully consult with their doctor when considering Mendi.

• Children
• Individuals with neurological conditions
• Individuals with mental health disorders
• Individuals with photosensitivity
• Individuals with diagnosed medical conditions

To ensure safety, we suggest clearly reading and following the manufacturer's instructions. The Mendi app has several educational videos about the technology and how to use the device correctly. While consistency is important, overtraining can cause mental fatigue and headaches.

User reviews and testimonials

While we gather scientific research and evidence, we also look at customer reviews to get a better idea of the device's real-world applicability and benefits. We have gathered user feedback on various sites like Reddit, Amazon, and Trustpilot.

What people liked

• Ease of use. The majority of customer feedback is focused on how easy Mendi is to set up and use. People also like that the training sessions are relatively short, making them easy to incorporate into their daily lives.
• Comfort. Several users liked that the band is adjustable, ensuring it sits comfortably on their heads.
• Noticeable benefits. Many buyers who use Mendi consistently report improvements in their productivity levels, focus, and stress management. Several users with ADHD mentioned that the technology has helped them improve focus and reduce anxiety about daily tasks. Several also mention better moods with consistent training.
• Real-time feedback. Several customers like the game-like training sessions and visual representation of the result in the app. They appreciated being able to track their performance and see an initial learning curve.

What people didn’t like

• Monotonous. Several users expressed the wish for more training exercises, as the one available can become repetitive and tedious over time.
• Calibration challenges. Electrode calibration requires stillness to read the signals correctly, which several users found challenging.
• Varied benefits. Although many users say Mendi is a game changer, many also feel that they saw no significant benefits, even with consistent use. A few also voiced concerns about the lack of clinical trials to validate the proposed benefits.
• Technical issues. Many users expressed a preference for USB-C charging instead of micro-USB. A couple also mentioned having issues syncing the device to their smartphones.

Tips and tricks for best results

Here are a few tips to optimize your training suggested by Mendi:

1. Find a calm place
2. Relax before your session
3. Make sure the headset sits firmly on your forehead but is not uncomfortable
4. Ensure there are no gaps between the sensors and the skin
5. Avoid direct light, as it can interfere with the sensor reading
6. Try to stay still and avoid moving your facial muscles during the session
7. Follow the in-app guidance after the syncing is complete

How much does Mendi cost, and where can you buy it?

Mendi Neurofeedback Headband costs $299 on the official website. It also includes the following features:

• Charging cable
• Free Mendi app
• 30-day money-back guarantee
• One-year hardware warranty
• Free international shipping to 40 countries

Currently, Mendi is only available to purchase on the official website. The app is subscription-free, and you gain access to all its features when you purchase the headset.

Comparison: Mendi vs. other popular alternatives

There are several other at-home neurofeedback devices available. So, we compared Mendi to the most popular alternatives.

Brand	Price	Technology	Personalized training	Guarantee	Support	Review
Mendi	$299.00 one-time purchase	fNIRS-based neurofeedback	Limited personalization via app	30-day money-back guarantee	Basic in-app support	–
Sens.ai	$799.00 one-time purchase	EEG-based neurofeedback and tPBM (transcranial photobiomodulation)	AI-driven personalizations	30-day return policy	In-app tutorials and support	Sens.ai review
Muse	$299.00 (Muse S Headband) + $14.99/month (app)	EEG-based neurofeedback	Limited personalization via app	30-day return policy	Email and app support	Muse review
Myndlift	$199.00 for the headband + $150.00/month or $399.00/3 months (app)	EEG-based neurofeedback	Customized by an assigned neurofeedback coach	30-day money-back guarantee	Monthly sessions with neurofeedback coaches and chat; in-app tutorials and education	Myndlift review
Neurosity	$1,499.00 one-time purchase	EEG-based neurofeedback	60-day personalized plan	90-day risk-free guarantee	In-app and website support	–

How and why we chose to review Mendi

We chose to review Mendi because at-home neurofeedback is gaining popularity. Together with the Research team, we spent a week looking into scientific studies and customer reviews to deliver you a thorough Mendi review. Our evaluation focused on the following aspects:

• Examining scientific research and clinical trials on fNIRS
• Reading through customer reviews about the product and the brand
• Looking into product features and pricing

Final verdict: is Mendi worth it?

Mendi may be a good investment for those who want to measure and track the blood flow in their prefrontal cortex and train their brain to potentially increase focus and reduce stress. The technology is noninvasive, and the training sessions are relatively short, making it easy to implement it in your life. We appreciate the 30-day money-back guarantee and the fact that the app with its full features is included with the device without the need to pay for a separate subscription.

On the other hand, although we appreciate the device's features, its potential benefits are still unproven, and there is a lack of scientific evidence to support them. The brand itself highlights that it is not a treatment for any conditions and that it should be combined with a healthy lifestyle for the best results. Also, you need to have at least a basic understanding of neurofeedback and how the brain works to reap the potential benefits.

All in all, Mendi may be a good addition to your wellness routine. However, positive lifestyle changes should come first.