Are you one of the few people who have heard about pulsed electromagnetic field therapy? Some wellness influencers make it sound as if this PEMF therapy is some form of panacea.
PEMF therapy devices may help you with chronic pain, sleep issues, inflammation, heart disease, complex chronic conditions like Lyme disease, and more. But how valid do you think these claims are?
For this blog post, I am digging deep into the science behind PEMF to show you the underlying mechanisms of how this technology works. In other words, I'll be exploring the question: "what is PEMF?"
Before we consider how PEMF technology works, let me give you a clear understanding of its definition. In this article, you will discover its rich history, the physiological effects of PEMF, several dosing strategies, and more.
PEMF is notably different from other technologies you may have experimented with that use the electromagnetic spectrum. Let us start with defining PEMF—a scientific term that sounds quite abstract.
The scientific literature has many different designations for this therapy, just to name a few:
For our purposes in this article, I simply call it PEMF.
The essential term for you to note within pulsed electromagnetic field therapy is electromagnetic. From a physics perspective, electromagnetism is simply a force.
PEMF uses the electromagnetic spectrum in the same way your radio, cell phone, or red light therapy devices do. You can view the complete electromagnetic spectrum below.
(Source, CC BY-SA 3.0 license. Filename: EM Spectrum Properties edit.svg. Created 26 October 2007.)
In this blog post, we are focusing on the radio wavelength part of the electromagnetic spectrum. PEMF therapy devices use frequencies within that radio wave spectrum.
In contrast to the potentially damaging health effects associated with cell phone use—PEMF devices aim to improve your health.
You might want to make a mental note that the P in PEMF denotes pulsed electromagnetic waves. Electromagnetic fields (EMFs) are usually pulsed in PEMF form but not always. As you may have guessed, pulsed simply means continuously turning the radio waves on and off. Studies examining non-pulsed EMF exist as well as PEMF studies.
Hertz (Hz) is the scientific measurement of wavelength cycles per second. If you measure a radio wave that oscillates 100 times per second, you would say it is 100Hz. The International Telecommunication Union classifies all frequencies between 3–30Hz as extremely low-frequency (ELF).
As you can see, there are not many ELF cycles per second because their wavelengths are between ten thousand to one hundred thousand kilometers or 6,213–62,137 miles. You may find it interesting that we humans have the capacity to hear sounds between 20–16,000Hz.
The Earth gives off an electromagnetic field which is present up to an altitude of 50km. The scientific name for the range of frequencies within this natural field is Schumann Resonance. It naturally ranges from 5 to 50Hz, with a peak frequency of around 8Hz.
Human beings appear to have a particular sensitivity to this range. When you think about it, that is fairly similar to the ELF range of 3–30Hz. For comparison, we have the ability to hear sounds between 20–16,000Hz.
Would you believe electromagnetism was a promising treatment modality in the early 1900s? It fell out of favor in 1910 when the Flexner Report was published. That report removed several therapies that were considered pseudoscientific from the medical mainstream and defined the modern practice of medicine we have today.
Unfortunately, electromagnetic therapy was also a casualty of the Flexner Report. You will be glad to know, these therapies did continue to develop behind the scenes by medical researchers who believed in their usefulness.
In the 1930s, researchers created an RF-EMF device to deliver heat to deep tissue. Some thought the device might produce non-thermal physiological effects too. To test this, they pulsed the EMF signal off and on so the machine would not emit heat.
It was not until 1934 that the first study showing positive outcomes was published. Did you know the FDA cleared the first RF-PEMF device, the Diapulse, for the treatment of pain and swelling in 1950?
By the 1970s, veterinarians began placing electrodes inside animal bones to treat non-union fractures. Over time, inductive antennas were used to transmit PEMFs and replaced the need for electrodes. We had to wait until the 1980s before the FDA approved PEMF devices for human use.
As you can imagine, PEMF therapy's mechanisms of action were still a mystery back then. Throughout the 1990s, researchers built an understanding of the mechanisms activated by PEMF. Their discoveries fueled the development of devices designed to target specific biological processes.
Thanks to the internet, PEMF entered a renaissance beginning in 2010. You will be glad to hear, it is gradually gaining momentum. Today, more and more of us are discovering the potential benefits of PEMF. You may be surprised to know, as of yet, there is no standardized therapy called PEMF.
Now that you have a deeper understanding of where PEMF came from, let us look at different types of PEMF.
PEMF therapy is the application of primarily extremely low-frequency radio waves (ELF) to the body with the goal of improving health.
The pulsed radio waves turn on and off at specific intervals. The activation of those radio waves creates a waveform, a term descriptive of the shape that the frequency takes on a graph as it approaches its highest and lowest points.
You might like to see a visual display of a few waveforms.
Does the waveform snap straight to full power and then abruptly shut off? In that case, it forms a square waveform on a graph. Does the waveform gradually turn up and down at a steady pace? If so, then this waveform follows a sine wave.
As you may already know, waveforms can also follow more complex patterns.
Some studies indicate that the waveform of the pulse is crucial for achieving particular goals. Targeted PEMF devices are FDA-approved for specific purposes.
You will notice in the graph below, the waveforms labeled "A" are approved to treat non-union fractures, compared to those recommended for pain and swelling, which are labeled "B." Can you believe how different these two waveforms look?
For some reason, PEMF has shown inconsistent results for treating pain and swelling since its initial approval.
Non-targeted PEMF devices use a wide range of settings. Research shows that this provides a diverse array of potential benefits. As you would assume, these vary along with the frequencies, intensities, and doses applied.
The treatment variables for achieving health benefits from non-targeted PEMF remain undefined. You see, the problem is that the overall research on PEMF is lacking. It is unclear how well research on one type of settings applies to others. Changing the waveform, intensity, frequency, or exposure time might alter the results for our desired outcomes.
You may wonder if it is possible to get all these benefits from the Earth's natural magnetic field. The primary differences between natural and engineered magnetic fields are the variations in frequencies and intensities.
The effects of EMF and PEMF exposure are highly variable. I am sure you have seen studies showing that if men keep their cell phones in the pocket of their trousers, it reduces their sperm quality. Going for a walk outside in the Earth's natural electromagnetic field does not have that deleterious effect, thankfully.
For most conditions we have begun to study, PEMF looks very promising. You may be interested to know that some clinical studies found benefits of PEMF use for humans.
In most cases, we have in vitro evidence showing it is plausible that PEMF should theoretically produce a benefit in people despite the limited clinical proof we currently have. As you can imagine, such in vitro studies are foundational even though they do not involve laboratory studies of complete biological organisms such as rats or humans.
Depending on how you look at it, a benefit may result from a diverse range of settings. Certain studies have only ever looked at one or two parameters. Other times, it seems like a benefit may appear in one context but not another. That is puzzling, wouldn't you agree?
As you know, benefits might be found in one study but not another due to different sets of variables or statistical flukes. The latest scientific literature acknowledges that additional PEMF research is needed. I would definitely like to see more scientific studies on it. How about you?
If you want a particular benefit, your best course of action is to look at specific clinical trials. Then choose a device that copies the frequency, intensity, and duration used in that study.
PEMF devices offer consumers a wide range of settings. The abundance of options available to us makes it hard to know how to dial in the precise parameters we are hoping will produce the desired benefit.
My goal, in this series of articles, is to equip you to both avoid marketing exaggerations on the one hand and overly skeptical dismissals on the other. It is not my intent to make a guide to the use of all PEMF products. I am going to give you the most recent scientific reviews available as we discuss each condition together in a future article.
Where possible, I want to share with you the PEMF settings that seem to deliver the most benefits. Would you like to take a closer look at the scientific methodology and how to assess PEMF studies?
We can all agree, definitive study results are lacking, so I will refer to the most reliable evidence that does exist.
As you know, randomized controlled trials (RCTs) are ideal, preferably with double-blinded placebo controls (DB-RCT). In the absence of these, the next best thing we can do is refer to in vitro cell studies, animal studies, or case reports.
I am pleased to tell you, compelling evidence exists that PEMF promotes healing and bone density. For every other condition, the evidence is too limited to justify our confidence just yet.
It is usually still possible to draw preliminary conclusions from even those small, limited human research studies that look at the physiological mechanisms PEMF activates. From there, you can formulate a reasonable hypothesis for PEMF self-experimentation.
Lastly, you may wonder how PEMF is different from other electromagnetic therapies. We can compare these therapies in a bit more detail if you want.
You most likely have never heard of rapid transcranial magnetic stimulation, abbreviated rTMS. It is an FDA-approved treatment for depression that does not respond to antidepressants. Patients receive sessions of rTMS at professional clinics.
Some manufacturers cite studies on rTMS to support claims about potential PEMF benefits. PEMF has shown promise in the treatment of depression. Supporting evidence for PEMF is more limited than the proof for rTMS. While rTMS is technically a form of PEMF, there may be significant differences, as you can imagine.
The rTMS approach pulses an intense field, for a short duration, directed at a specific part of the brain. This field is strong enough to force neurons in the targeted region of the brain to fire. Imagine you were going to undergo this therapy. The way they locate the brain region to target for depression treatment starts with finding the area of your brain that would cause your thumb to twitch.
Ordinary PEMF does not create a field strong enough to force your neurons to fire or cause your thumb to twitch. Were that the case, your whole body would be twitching all night long while using a PEMF therapy device. You wouldn't want that.
PEMF pulses a much weaker field, usually for an extended duration, across a significantly larger area. This field may make it easier for your neurons to fire, but it does not force them.
Unlike rTMS, PEMF affects large parts of your brain at once. The objective of PEMF treatments is not to target specific brain regions. As a result of the non-targeted nature of PEMF, if you have anxiety, PEMF may be more likely than rTMS to make it worse.
Related mechanisms may create similar effects from rTMS and PEMF. Until studies confirm this, there is currently no way for us to know precisely how comparable these effects may be. Studies of rTMS suggest avenues for future research on PEMF. Obviously, those rTMS studies cannot substantiate claims of specific benefits for PEMF.
You get the picture that there is still ongoing controversy over the ideal frequency, intensity, magnetic placement, and dosing to apply, even in rTMS. If rTMS still needs answers to these basic questions, despite its mainstream use, PEMF needs it even more, right?
There are trials underway for a weaker rTMS device that you could use at home. That device reduces the required dose to a safe level for home application by calculating your alpha brainwave rhythms. Isn't that great? Of course, PEMF devices do not yet have that capacity (1, 2, 3).
Next up, I'll give you my take on PEMF and brainwave entrainment.
Have you heard the theory that PEMF works through brainwave entrainment? It's quite prevalent but completely false. Brainwave entrainment is an effect that occurs in response to flashing lights and pulsing sounds.
Entrainment works by flashing a light or pulsing a sound on and off. If the pulse is cycling at 10Hz, your brain gradually produces more 10Hz brainwaves. Generally speaking, slower or faster brainwaves correspond to increased amounts of inner or outer awareness in response. Brainwave entrainment can help you bring about particular states of consciousness.
A ground-breaking study showed that slower theta wave recordings could benefit your long-term memory recall. Executive control increased using faster beta wave recordings, as found in another study. It is exciting that alpha wave recordings are effective at improving your moods according to a third study.
Some studies fail to find an entrainment effect from light and sound. Typically, those studies only test brief exposure times. Here is a study that found no impact from exposing participants to binaural beats for 2–4 minutes.
Doesn't it seem reasonable to you that it may take 15 minutes or more to produce an entrainment effect? If that is the case, wouldn't you agree that even their longer four-minute exposure was an inadequate duration to produce the desired results?
You would think PEMF could cause an entrainment effect like this, right? We know our brains entrain to the frequency of a pulse, whether the pulsing stimulus is light or sound.
I would have assumed our brains should respond the same way to a pulsing electromagnetic field, wouldn't you? Surprisingly, pulsing electromagnetic fields do not elicit the same response as pulsating lights or sounds.
You won't believe this, but a study of patients with Parkinson's disease found that a theta pulse (5Hz) increased beta wave activity in specific brain regions affected by Parkinson's. How is that possible?
Some PEMF products operate on the assumption that they entrain your brainwaves by mimicking the pattern of your brainwaves during sleep. There is only one study showing PEMF at 4Hz can improve sleep, but that gives us hope that future studies will support those findings.
No studies have examined the effect of shifting your exposure to a different PEMF frequency during the night. Since there is no evidence for any entrainment benefits yet, I cannot tell you what effect that might have.
One study placed rats in an artificial electromagnetic field, then changed it. They found that the changes they made to it inhibited melatonin. It was the change, not the particular state, that had this effect. This study did not change the frequency. Instead, it inverted the horizontal axis of the field. You can see how all these changing variables can have unforeseen effects.
Still, this is the only evidence available on what changing EMF does for sleep. Until we examine this further, all we know is that it is possible that altering the natural frequency could have a similar effect on melatonin production in humans. I don't know about you, but I sure don't want anything to decrease my nighttime melatonin levels.
Several studies have examined the EEG entrainment response to cell phone EMFs. When cell phone use causes changes to happen in your brain, it results in increased alpha wave production. I can tell you that, in most cases, cell phone EMFs increase alpha waves. Rarely do they reduce alpha waves or have a neutral effect.
Only two studies have measured EEG after PEMF exposure in healthy subjects. Both conclude that PEMF increases alpha wave production irrespective of the frequency (1, 2). That makes sense, considering what we know about cell phone EMFs.
A final point for you to keep in mind is that the changes in brainwave responses to any kind of EMF exposure vary from person to person. Even the best-controlled studies can underestimate individual variation.
In any study with a placebo control group, you would expect a third of participants to improve, a third to worsen, and a third to see no change. Theoretically, a particular intervention could directly cause a third of the subjects to get better and a third to get worse. Yet you wouldn't know it because that hypothetical RCT makes it look like the intervention was a placebo, even if the experiment variable induced the results.
You're probably aware that there is an ongoing debate over how the effectiveness of antidepressant prescriptions compares to the placebo effect. Some studies suggest antidepressants are hardly any better than a placebo. You won't be surprised to hear that most study reviews say prescription medications are more effective than a placebo. If you are wondering, "Why was the evidence ever even open to argument in the first place?" It is because patients respond differently to various antidepressants.
You can take any study that seems to show negligible benefits for antidepressants over the placebo effect. You could examine only the participants that responded well to the antidepressant used in that study. What would happen if you stop the first drug, have a washout period, and then start a different one? You can see how those same participants may no longer respond favorably to the new drug.
If you put the study participant back on the original antidepressant, they might respond well to it again. If this happened, you would know that the benefit was not as much due to the placebo effect as it first seemed when there was only one drug being tested. Instead, after comparing different variables, you would infer the benefit occurred due to individual variation.
Theoretically, you could have an experiment that has a minimal net effect on a sizable group of people yet might have a dramatic impact on a few of them. You can see how these N=1 experiments can be valuable even when large-scale controlled studies already exist. Sometimes they can lead to observations that RCTs miss.
Perhaps, you are one of those people who consistently respond to EMFs with more alpha waves. Your friend might be one of the rare people who always respond with fewer alpha waves. Other people in your life might be ones who experience no effect.
Furthermore, other confounding factors could produce entirely different EEG changes, which we discussed regarding Parkinson's. As you would predict, a large trial exposing two groups to either a placebo or EMF only once before comparing the results would miss this.
You will want to keep these essential points in mind when evaluating the results of large-scale clinical studies. It is always possible that their findings underestimate the effects of the treatment on some individuals. Therefore, doing your own experimentation with PEMF is justified if performed safely.
While hertz (Hz) is a unit for measuring the frequency of wavelengths, the intensity of Earth's magnetic field is measured using three comparable scientific units of force. For comparison, one gamma (γ) equals one nanotesla (nT), which is also equivalent to 10−5 gauss (G).
A controversial body of evidence links changes in the Earth's magnetic field to adverse outcomes in us human beings. Here is a surprising inverse relationship for you to consider. As the intensity of the natural field increases from about 44,000 to 50,000 nanotesla, the male suicide rate increases, psychiatric admission rates increase, deaths from respiratory illnesses go up, heart-rate variability decreases, and blood pressure increases (1, 2).
The intensity of the Earth's magnetic field ranges from 0.25 to 0.65 Gauss. Some PEMF manufacturers sell devices at 650 or more Gauss. Sometimes they instruct users to use them for many hours overnight. What do you think about that?
Wouldn't you agree that any PEMF device that generates a field one thousand times more powerful than the Earth's is overkill? Those devices might even be harmful.
It is noteworthy that a conservative dose of only 0.038 Gauss achieves positive results for osteoporosis patients.
In a future article, I plan to give you more supporting evidence from scientific studies for PEMF treatments of various health conditions. To sum things up for you on the safety and effectiveness of PEMF, it seems that this technology is promising yet clearly needs more scientific backing.
I hope our introductory discussion has made you more curious about possible applications of PEMF therapy devices for a diverse array of health benefits. The best PEMF evidence so far is for bone healing. Most likely, other objectives are being targeted for research and development as well.
Right now, if you want to use PEMF for any specific purpose, it is probably best to read up on scientific studies. You will need to experiment with different settings since though there is no standardized therapy called PEMF. When applied with different intensities, waveforms, and radio wave frequencies, this technology is an innovative way to improve your health.
Studies might fail to capture the potential benefits of PEMF adequately. Hence, you might benefit from PEMF effects that are still unproven in scientific studies. Other advantages may not ever be proven because studies only register overarching effects among all the participants, not the atypical results of a few individual results that might be beneficial.
In the next installment, we will take a closer look at using PEMF for all your different health goals. Stay tuned!
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