The buyer / downloader of the royalty free brainwave entrainment music / downloads on this site assumes all risks in using the music, waving any claims against the owners of Royalty Free Meditation Music.com, its affiliates and its parent company, Spire Audio, for any and all mental or physical injuries. This includes all self-created suggestions for mood altering, brain wave states altering, and for self-improvement or motivation. The buyer/user also agrees to assume liabilities when other persons have access to the Binaural beats or any music / downloads and/or anything it produces, including WAV, MP3, files or CDs, whether for commercial or private use. In no case will Enlightened Audio.com, its affiliates and its parent company, Spire Audio, be liable for chance, accidental, special, direct or indirect damages resulting from the use or misuse of our music.
“A quite different phenomenon results when stereophonic earphones are used and the signals are applied separately to each ear. Under the right circumstances beats can be perceived, but they are of an entirely different character. They are called binaural beats. . . . Binaural beats require the combined action of both ears. They exist as a consequence of the interaction of perceptions within the brain.”
The brain has two hemispheres that operate somewhat independently from one another. The two hemispheric structures of the brain are connected by a large nerve, called the corpus callosum, which sends information back and forth between the two sides of the brain. In most people, the left hemisphere controls language, logical thinking, and analytic processes and the right side contains the centers for emotion, intuition, and non-linear creative thinking.
Hi Jason, thanks for all the uploads to youtube. I’ve been using them in work recently to help me concentrate and relax. I like the music tracks that you’ve chosen to overlay the tones. A couple of times in the last 2 weeks I’ve experienced the wavy pulse like sound, similar to the tones in my left ear. I wasn’t listening to tracks at the time or that day. It doesn’t last but it feels a bit strange. I wondered if I might have been listening to the tracks too loudly and that it was almost like a type of tinnitus. I’m curious to know if anyone has been in touch with you in the past to say they’ve had a similar experience?
You are already far beyond the need for using an entrainment product as a meditation aid. Those who sincerely believe this to be the case would not have come searching for a meditation site such as Project Meditation to help them learn and practice meditation and brainwave entrainment. They would probably not even bother with using an entrainment aid; hence this entire discussion would be irrelevant to them. The fact that you are here, reading this, seeking to benefit from incorporating meditation and brainwave entrainment to aid in your existing meditation practice suggests you are not one of these folks whose development is so advanced that entrainment is of no use to you.
it says the following: “Running a delta sleep session throughout the night is not recommended as it can interrupt the normal sleep cycle”. I’ve been looping pure delta isochronic tones for about 5 days now, and have had quality sleep. Should I continue looping delta or should I let the videos play out without looping them? Will it will harm my health to do loop delta while I sleep?
Binaural beats are auditory brainstem responses which originate in the superior olivary nucleus of each hemisphere. They result from the interaction of two different auditory impulses, originating in opposite ears, below 1000 Hz and which differ in frequency between one and 30 Hz (Oster, 1973).For example, if a pure tone of 400 Hz is presented to the right ear and a pure tone of 410 Hz is presented simultaneously to the left ear, an amplitude modulated standing wave of 10 Hz, the difference between the two tones, is experienced as the two wave forms mesh in and out of phase within the superior olivary nuclei. This binaural beat is not heard in the ordinary sense of the word (the human range of hearing is from 20-20,000 Hz). It is perceived as an auditory beat and theoretically can be used to entrain specific neural rhythms through the frequency-following response (FFR)--the tendency for cortical potentials to entrain to or resonate at the frequency of an external stimulus. Thus, it is theoretically possible to utilize a specific binaural-beat frequency as a consciousness management technique to entrain a specific cortical rhythm.  
When signals of two different frequencies are presented, one to each ear, the brain detects phase differences between these signals. "Under natural circumstances a detected phase difference would provide directional information. The brain processes this anomalous information differently when these phase differences are heard with stereo headphones or speakers. A perceptual integration of the two signals takes place, producing the sensation of a third "beat" frequency. The difference between the signals waxes and wanes as the two different input frequencies mesh in and out of phase. As a result of these constantly increasing and decreasing differences, an amplitude-modulated standing wave -the binaural beat- is heard. The binaural beat is perceived as a fluctuating rhythm at the frequency of the difference between the two auditory inputs. Evidence suggests that the binaural beats are generated in the brainstem's superior olivary nucleus, the first site of contra-lateral integration in the auditory system (Oster, 1973). Studies also suggest that the frequency-following response originates from the inferior colliculus (Smith, Marsh, & Brown, 1975)" (Owens & Atwater, 1995). This activity is conducted to the cortex where it can be recorded by scalp electrodes.  

When your thoughts start to spin out of control during a stressful moment, stop and reframe your thinking. “By your choice of perspective, you direct how your body will respond—in fight or flight, or in creative choices and solution-based responses,” says Lauren E. Miller, stress relief and personal excellence expert and the author of 5 Minutes to Stress Relief. If you’re stressed about something you fear happening, such as “I’m not going to get this project done and then my boss will fire me,” think instead of what a great opportunity it is to show your boss you’re a hard worker. “Resist the urge to cast yourself as the main character in dramas that have not even occurred,” Miller says. Also, instead of asking why something is happening, ask what you can do to fix it. “Asking ‘why’ pitches you in an endless loop of questions, whereas asking ‘what’ sets you into problem-solving mode,” says Deborah Serani, PsyD, award-winning author of Living with Depression and a psychology professor at Adelphi University. “Moving forward instead of being lost in the circle of worries and “whys” helps to reduce stress.” Try these simple mindfulness stress relievers.


You are using an entrainment product that is not well designed and is not assisting you with your meditative practice. Since we’re focusing on the use of LifeFlow it would be fair to point out that it has shown itself to be highly effective by literally hundreds of users registered on our forum, facebook page and Blog. Its technical attributes have proven themselves over time. There are, of course, other products on the market which are also effective. We can safely say that LifeFlow has demonstrated that it works. Failure to experience its benefits are not due to defects in design or technical specifications.

“Stress and sleepless nights are closely linked,” Buenaver says. “If you’re in pain, tend to worry, or are coping with a difficult situation in your life, you may have more stress hormones than usual circulating in your body. A poor night’s sleep adds even more. And those hormones may never be fully broken down. It’s like running an engine in fifth gear all the time.”
“A quite different phenomenon results when stereophonic earphones are used and the signals are applied separately to each ear. Under the right circumstances beats can be perceived, but they are of an entirely different character. They are called binaural beats. . . . Binaural beats require the combined action of both ears. They exist as a consequence of the interaction of perceptions within the brain.”
However, yoga and meditation take time to learn and master, and until the student becomes proficient, progress can be slow and frustrating, leading many people to abandon the effort before they see the benefits. Brainwave entrainment has the potential for helping a person enter the relaxing and rejuvenating mind-states brought about by yoga and meditation without the learning curve and time needed for mastering these other techniques. Brainwave entrainment may even facilitate learning other mindfulness methods by helping a person achieve success faster and more reliably. 
One faulty expectation as it pertains to brainwave entrainment is that listening to an entrainment track is the same as meditating. If you’ve understood the principles so far as they’ve been laid out you understand why this idea is completely untrue. If the answer is not yet obvious to you, read the material covering these principles again and try to grasp their meaning.
One can also learn to control and slow down their brain waves through various neurofeedback technologies such as electroencephalograph (EEG), galvanic skin response (GSR), and heart, pulse and breath rate monitors. These devices measure stress and relaxation parameters and then "play" back the signals to the user so they can use the signals as a beacon to guide and "steer" themselves into a relaxed state. This takes some time, work and discipline but is much quicker than learning meditation.
You are already far beyond the need for using an entrainment product as a meditation aid. Those who sincerely believe this to be the case would not have come searching for a meditation site such as Project Meditation to help them learn and practice meditation and brainwave entrainment. They would probably not even bother with using an entrainment aid; hence this entire discussion would be irrelevant to them. The fact that you are here, reading this, seeking to benefit from incorporating meditation and brainwave entrainment to aid in your existing meditation practice suggests you are not one of these folks whose development is so advanced that entrainment is of no use to you.
The final suggestion I have to offer is that you make your practice a regular, consistent habit. You don’t have to be perfect but you do need consistency. Like any other skill, entering meditation will develop in direct proportion to the consistency of your practice. Missing a session occasionally is not going to derail all your progress. But frequently skipping or blowing insincerely through practice is not going to produce any noteworthy results. There isn’t any hard and fast rule from frequency of practice that always applies to everyone, but most of us will instinctively know whether or not we’re giving our practice the time and effort it requires.

The brain has two hemispheres that operate somewhat independently from one another. The two hemispheric structures of the brain are connected by a large nerve, called the corpus callosum, which sends information back and forth between the two sides of the brain. In most people, the left hemisphere controls language, logical thinking, and analytic processes and the right side contains the centers for emotion, intuition, and non-linear creative thinking.


In other words, you give the well a little taste of what it is you want from it, and then the well responds by delivering more of the same back to you. In the case of the water well, you pour a small amount of water down into the pump. This is known as “priming” the pump. Until you do this the pump does not produce the water you’re looking for. Once you prime the pump it sets up the conditions in which that pump can do its job and the water begins to flow.
A study published in Electroencephalography and Clinical Neurophysiology by Paul Williams and Michael West in 1975 examined the brainwave states of people experienced in meditation while using photic stimulation, and another study by Leonard, Telch, and Harrington in 1999 examined the successful use of brainwave entrainment techniques for attaining meditative states in subjects.
Although getting organized and staying organized is not often thought of as a stress management technique per se, this is an activity that can reduce the stress you face in your life, and can even be calming as you are engaged in the act. (See how cleaning can be a stress reliever in itself.) By working through the clutter of your life, you can eliminate those energy drains that can make you feel like you're 'being pecked to death by ducks' and reserve that energy for dealing with life's more important challenges. Read more on being organized and eliminating extra stress from your life. 
Other entrainment methods sometimes used include autopan modulation that moves sound in an 180º arc to create a desired tone. Harmonic box entrainment, invented by James Mann, uses a layering of binaural and monaural tones that alternate between ears, requiring headphones. Sound modulation and filtering, amplitude modulation, and pitch panning use diverse sounds to create rhythmic pulses matched to the desired brainwave frequency. 

There isn’t really a one-size-fits-all track or frequency range which is right for all kids while doing homework. So that does make it difficult to recommend one thing in particular, and why I have a number of tracks for studying and focus. If they have already learnt and understood the information, but are just trying to commit it to memory for a test, then I would recommend an alpha track, like the Memorization Study Aid product I have with the 10.4Hz frequency you referred to. If they are still trying to fully understand what is being taught in a workbook, then I would recommend a track that is mainly beta frequencies, like my Study Focus tracks. In the middle, I have a number of tracks which use a combination of beta and alpha wave frequencies, like Study Booster, Study Enhancer and Cognition Enhancer. The last 3 use similar frequencies but deliver the tones and brainwave entrainment effects in different ways. As we are all wired a little differently it does sometimes take a bit of trial and error, to see what method or frequency range works best for the individual. These types of tracks are made for a general audience. In an ideal world, you would hook up to an EEG and see in real time exactly what a person responds to best, depending on the goal and current state of mind.

In other words, you give the well a little taste of what it is you want from it, and then the well responds by delivering more of the same back to you. In the case of the water well, you pour a small amount of water down into the pump. This is known as “priming” the pump. Until you do this the pump does not produce the water you’re looking for. Once you prime the pump it sets up the conditions in which that pump can do its job and the water begins to flow.


Alpha is the next level down, between 8Hz - 12Hz, corresponding to being awake but deeply relaxed. It can be a little confusing that Alpha is lower than Beta, but it is named that way because Alpha was the first brainwave "discovered" (identified) by Hans Berger in 1929. Meditating in this state is very relaxing and most people find it very easy to become entrained in this frequency.
When two pure tones of slightly different frequencies are delivered simultaneously to the two ears, is generated a beat whose frequency corresponds to the frequency difference between them. That beat is known as acoustic beat. If these two tones are presented one to each ear, they still produce the sensation of the same beat, although no physical combination of the tones occurs outside the... [Show full abstract]
A large dose of caffeine causes a short-term spike in blood pressure. It may also cause your hypothalamic-pituitary-adrenal axis to go into overdrive. Instead of coffee or energy drinks, try green tea. It has less than half the caffeine of coffee and contains healthy antioxidants, as well as theanine, an amino acid that has a calming effect on the nervous system.
I would personally stay away from higher frequencies (such as Gamma tracks) if the issue is overly-developed upper chakras. Perhaps try lower frequencies such as Delta as they help you to stay more in your body. And yes, if you move onto other pages, provided that the link you originally came from was from our site, a small commission will still be issued at no extra cost to you. :) As for your question about the deep meditation track, you might like to directly get in touch with the creators (as they will be more qualified to answer your question): https://www.binauralbeatsmeditation.com/contact/ I hope this helps, Kim!
Brainwave Entrainment is an assisted form of meditation using pulses of sound. Entrainment is a process of synchronizing two different beats to become harmonious. Brainwave entrainment works by pulsing a different sound in each ear to stimulate the brain into altered states of consciousness. Examples including Binaural Beats and Isochronic Tones, which are best experienced with headphones to assist with relaxation, deep sleep and focus.

When you play a tone with a slightly different frequency into your left and right ear — say, 200 hertz (Hz) in one and 210 Hz in the other — they travel separately to your inferior colliculus, the part of your brain that gathers auditory input. There, the tones “squelch” together into a so-called “beat” at a perceived new frequency. (In this case, it would be 10 Hz.)
Articles and information on this website may only be copied, reprinted, or redistributed with written permission (but please ask, we like to give written permission!) The purpose of this Blog is to encourage the free exchange of ideas. The entire contents of this website is based upon the opinions of Dave Asprey, unless otherwise noted. Individual articles are based upon the opinions of the respective authors, who may retain copyright as marked. The information on this website is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical advice. It is intended as a sharing of knowledge and information from the personal research and experience of Dave Asprey and the community. We will attempt to keep all objectionable messages off this site; however, it is impossible to review all messages immediately. All messages expressed on The Bulletproof Forum or the Blog, including comments posted to Blog entries, represent the views of the author exclusively and we are not responsible for the content of any message.
Move-Thru-It Strategy: to support optimum recovery rates, use 6-8 pumps or 3-4 droppers. Repeat every 1-3 hours for a day or two (with a good night's sleep). The idea here is a persistent frequency. Once you have achieved initial results, you can switch to more conventional usage patterns such as 3-4 times a day. For example: Kick-Ass Immune, Get Over It 

Most capsules either contain powdered, dry herbs, or a tiny bit of liquid extract (gel caps). Tablets are powdered herbs that are held together by pressure and other chemicals. The beauty of liquid extracts, or "tinctures," is that they absorb quickly and the body receives the full benefit of the plant in a very bio-available solution. Liquids also allow you to customize your serving freely so you can best meet your needs at the time. Liquids are inexpensive and easy to swallow. The droppers and pump top dispensers are also convenient for when you're on the go.
Resonant entrainment of oscillating systems is a well-understood principle within the physical sciences. If a tuning fork designed to produce a frequency of 440 Hz is struck (causing it to oscillate) and then brought into the vicinity of another 440 Hz tuning fork, the second tuning fork will begin to oscillate. The first tuning fork is said to have entrained the second or caused it to resonate. The physics of entrainment apply to bio-systems as well. Of interest here are the electromagnetic brain waves. The electrochemical activity of the brain results in the production of electromagnetic wave forms which can be objectively measured with sensitive equipment. Brain waves change frequencies based on neural activity within the brain. Because neural activity is electrochemical, brain function can be modified through the introduction of specific chemicals (drugs), by altering the brain's electromagnetic environment through induction, or through resonant entrainment techniques.
We may use the term “to meditate” as a convenience, but always keep in mind, what is really meant is that we enter into a state of meditation. It’s an important point to distinguish because if we get caught in the trap of regarding meditation “as a verb” it leads into all sorts of problems and misunderstandings. If a person incorrectly believes meditation is a verb, they generally also confuse whatever technique they use to arrive at a state of meditation as being meditation in and of itself.
Most capsules either contain powdered, dry herbs, or a tiny bit of liquid extract (gel caps). Tablets are powdered herbs that are held together by pressure and other chemicals. The beauty of liquid extracts, or "tinctures," is that they absorb quickly and the body receives the full benefit of the plant in a very bio-available solution. Liquids also allow you to customize your serving freely so you can best meet your needs at the time. Liquids are inexpensive and easy to swallow. The droppers and pump top dispensers are also convenient for when you're on the go.
Many people exercise to control weight and get in better physical condition to become more healthy or physically attractive, but exercise and stress management are also closely linked. Exercise provides a distraction from stressful situations, as well as an outlet for frustrations, and gives you a lift via endorphins as well. This article can tell you more about the stress management benefits of exercise, and help you get more active in your daily life.
Social interaction is your body’s most evolved and surefire strategy for regulating the nervous system. Talking face-to-face with a relaxed and caring listener can help you quickly calm down and release tension. Although you can’€™t always have a pal to lean on in the middle of a stressful situation, maintaining a network of close relationships is vital for your mental health. Between sensory-based stress relief and good listeners, you’ll have your bases covered.
Isochronic tones are the newest technological advancement in the field of brainwave entrainment. Isochronic tones are regular beats of a single tone. In fact, an isochronic tone is a tone that is being turned on and off rapidly at regular intervals, creating sharp and distinctive pulses of sound. This effect called “Amplitude Entrainment” tends to excite the thalamus and causes the brain to generate the same brainwave frequency (“frequency following response”) as the tone. The thalamus, vital structure lying deep within the brain, has multiple important functions: it is involved in sensory and motor signal relay, and the regulation of consciousness and sleep. Therefore, the use of isochronic tones is a very effective way to induce a desired brainwave state.
Hi Ulka, thanks for your compliment on my article. Unfortunately, I haven’t come across any studies or much discussion about the problem with habituation and isochronic tones and how to overcome it. The consensus among experienced users is to regularly change the frequencies and music soundtracks you listen to. Adding music to the tones does change the waveform you are stimulated with, so that’s one of the main reasons why I provide different soundtracks for my isochronic tones sessions. I have released some tracks which use amplitude modulations in the music, instead of isochronic tones. It might be worth giving them a try if you haven’t already. I have them in a playlist on YouTube https://www.youtube.com/watch?v=Lj5tHl2cuWw&list=PLveg0IEcZWN6OIRZyLkv0BJADY7Q6xFCl.

Ever wish a stress superhero could save you from the tension of traffic jams, chaotic meetings, arguments with your spouse, or a toddler’s tantrums? Well, you can be your own stress-busting superhero. Using your senses, you can tap into the power to reduce the impact of stress as it’s happening and stay in control when the pressure builds. Like any skill, learning how to ease stress in the moment takes time, experimentation, and practice- but the payoff is huge. When you know how to quickly relieve stress, you can stay calm, productive, and focused, €”no matter what life throws at you.

Doing almost any routine, repetitive activity (like vacuuming, shredding paper or knitting), or reciting a word that represents how you wish you felt (such as calm) is a quick way to achieve a Zen-like state. Studies show the effects lower blood pressure and slow heart rate and breathing. The crucial elements are to focus on a word, your breathing or a movement and to bring your attention back to your task if your mind wanders or negative thoughts intrude. Or look to your faith for a mantra: A recent study published in the Journal of Advanced Nursing found that repeating phrases with spiritual meanings helped participants cope with a range of problems, from anxiety to insomnia.
ClickBank is the retailer of products on this site. CLICKBANK® is a registered trademark of Click Sales, Inc., a Delaware corporation located at 917 S. Lusk Street, Suite 200, Boise Idaho, 83706, USA and used by permission. ClickBank's role as retailer does not constitute an endorsement, approval or review of these products or any claim, statement or opinion used in promotion of these products.
Let’s face it, the stress we face today isn’t going anywhere, which is exactly why it’s more important than ever to find natural ways to bust stress that work well for us. If you’re up against large amounts of stress in your life (and who isn’t?), studies show you can greatly benefit from carving out more time in your busy schedule for things like regular exercise, meditation, spending time outdoors and keeping up with fun hobbies.
In addition to potentially boosting sleep-promoting hormones, binaural beats may also reduce our perceptions of pain. A 2017 study found binaural beats used in combination with visual stimulation led to reductions in patients’ perception of acute pain. Other recent research showed binaural beats helped improve pain perception in patients with chronic pain.
Thanks for your compliment on my article. 🙂 There are some frequency lists which reference and quote some links to metabolism, but I don’t know how effective or reliable that information is. One of the good things but also a drawback of this technology is how accessible it is to use and create tracks. That makes it unattractive for big companies to invest in large-scale research because it’s hard to patent and protect any product they produce based on the research. As soon as they released the frequency data, people like me would produce free videos and cheap MP3s to utilise the research, so they wouldn’t be able to get a good return on their research investment. So to try and gain some insight into what is working for people, at the moment, we are relying upon assessing anecdotal feedback in many areas. Before buying any products/tracks for increasing metabolism, I would look for and try out free videos on YouTube first, to try and gauge how those particular tracks and frequencies work for you.
Theta waves are associated with ➤ Increased sense of inner peace and emotional stability ➤ Deep relaxation ➤ Improved memory ➤ Heightened intuition and inspiration ➤ Calms the chatter of your mind ➤ Increased psychic abilities and sense of spiritual connection ➤ Speed healing, improved physical healing ➤ More restful sleep ➤ Release beneficial hormones related to health and longevity ➤ Reduce mental fatigue ➤ Reduction of anxiety and stress
Hi Marko, that isn’t one of my videos you referred to, so I can’t really answer you properly as I don’t know how their track was created. For the best answer, you should really contact the video creator. There isn’t any research that I’ve seen to suggest that you could harm your health by looping a delta track. During a typical sleep cycle, your brainwave activity will usually go up and down between the delta and theta range. It may be that you won’t experience the same quality of sleep if you spend most of your time producing mainly delta activity. With my 8-hour sleep track, I fluctuate the frequency range to try and emulate a typical sleep cycle http://www.mindamend.com/shop/sleeping-and-dreaming/deep-sleep-8-hour-sleep-cycle/.
... These factors may be the specific frequency of BB; the targeted population-because it is known that older people have different quality of brainwave activity than, e.g., youngsters (Bazanova & Aftanas, 2008;Clark et al., 2004), and the tests used to detect the possible changes in working memory capacity. Based on the research showing a positive impact of alpha-range BB on cognitive functioning, specifically attention, auditory sequential memory, working memory, working memory storage, reasoning ability, cognitive processing and hemispheric synchronization, (Carter & Russell, 1993;Cruceanu & Rotarescu, 2013;Foster, 1990;Kennerly, 1994;McMurray, 2006) as well as on the wealth of research documenting the important role of alpha brain wave activity on vigilance, in-hibitory processes, attention, filtering out irrelevant information working memory, the visuo-spatial component of working memory, perceptual abilities and information processing speed (Braboszcz & Delorme, 2011;Clark et al., 2004;Engle et al., 1999a;Freunberger et al., 2011;Klimesch et al., 2007;Lachat et al., 2012;Oprisan, 2004;Palva & Palva, 2007;Rihs et al., 2007;Sauseng et al., 2009;Tuladhar et al., 2007;VanRullen & Koch, 2003), we believe that BB of a frequency that corresponds to the alpha range of brain activity has a temporary effect on working memory capacity. In our study, subjects were exposed to 9.55 Hz BB stimulation while we measured their working memory capacity through the Automated Operation Span Task (AOSPAN). ...
Exercise can be an effective component of a stress management program for many individuals and should be recommended to help those who are dealing with acute, acute episodic, or chronic stress. An advantage of incorporating exercise into a stress management program compared with other stress management techniques is the well-documented physical and psychological health benefits of exercise. However, it is important to remember that exercise is only one component of a stress management program, and there might be situations that require assistance beyond the expertise of a fitness professional, especially in working with individuals who are experiencing acute episodic or chronic stress. Although exercise might be effective in helping an individual feel calmer who is dealing with these types of stress, it will not solve the problem of major chronic or regular stressors. It may be necessary to refer these individuals to resources who can help them to address their stressors, such as a psychologist or other health care providers.
A combination of strokes works well to relieve muscle tension. Try gentle chops with the edge of your hands or tapping with fingers or cupped palms. Put fingertip pressure on muscle knots. Knead across muscles, and try long, light, gliding strokes. You can apply these strokes to any part of the body that falls easily within your reach. For a short session like this, try focusing on your neck and head:
There are five main categories of brainwave frequencies: Gamma (40Hz+), Beta (13 – 40Hz), Alpha (7 – 13Hz), Theta (4 – 7Hz), and Delta (<4Hz). Each category is associated with a different state of mind; so, for example, when you’re in a peak state of performance, your brain produces Alpha Waves, and when you’re in a deep sleep, your brain produces Delta Waves.
The objectives and inclusion criteria of the review were clear. Relevant sources were searched for studies, although the restriction to published studies in English meant that the review was prone to publication and language biases. The authors did not state whether steps were taken to minimise the risk of bias and error in the processes of study selection and data extraction (for example, by having more than one reviewer independently make decisions). The authors mentioned which studies were blinded, but it did not appear that study validity was systematically assessed, which made it difficult to judge the reliability of the review findings. The decision to combine studies by narrative synthesis appeared appropriate given the strong clinical heterogeneity between the studies, but the authors failed to quantify the size or statistical significance of the findings reported. The evidence presented appeared to justify the authors’ conclusions that further research was justified, but in view of the dearth of good-quality evidence and problems with methodology and reporting in the review, the conclusions regarding efficacy did not appear reliable.
×