Pulsed Light Therapy: Beneficial or Bogus?
Using short bursts of light, or “pulsing,” is a much discussed current trend that supposedly makes light therapy more effective. Although the method does have scientific backing for use with lasers, many companies are touting it as an innovative way to use light-emitting diode (LED) therapy as well.
But does it work for all types of light?
The short answer is no. Pulsed light is effective for lasers because it helps offset a major drawback of extremely focused light: excessive heat. But this problem is only associated with the use of lasers.
Other types of light therapy, including red and most any LED therapy, are actually less effective when used in a pulsed pattern. In this article we’ll examine why that is, and what application method you should use instead.
The Study That Started the Pulsed Light Trend
To fully comprehend any trend, it’s helpful to understand how and where it started. In this case, it was a study by Dr. Michael Hamblin, an associate professor at Harvard Medical School, who is one of the preeminent experts on all things light therapy.
In 2010, Dr. Hamblin worked with a team of scientists and doctors to find the most effective application method for low-level laser therapy (LLLT). They compared two possible varieties: pulsed wave and continuous wave. Each method was run through a rigorous analysis, and at the conclusion, pulsed wave emerged as the winner. In the study, which was published in the July 2010 issue of Lasers in Surgery and Medicine, the authors write:
“This review of the literature indicates that overall pulsed light may be superior to [continuous wave] light with everything else being equal.”
The study’s conclusion has since been widely interpreted to mean that pulsing is superior and therefore should be used for all types of light therapy, including LED. But there’s one significant problem with these second-hand interpretations: The original study only applies to lasers.
Lasers Get Results - but at a Cost
Until just a few years ago, lasers were the only illumination method used for light therapy. Other light sources, such as LEDs, simply couldn’t produce enough power to provide meaningful results.
Lasers, on the other hand, produce extremely focused light that penetrates deep into the skin and even internal organs. Once there, the light energy stimulates the body’s mitochondria, or energy center of cells, which results in a host of benefits, including improved cellular health, increased collagen production, and better blood flow, just to name a few.
But even though the benefits of lasers were undeniable, they were often accompanied by an unpleasant side effect. When exposed to lasers continuously for more than a brief moment, the outer layer of skin would burn. Unfortunately, this meant a laser’s primary benefit was also its Achilles heel, which made it frustrating to use.
Pulsing alleviated this negative effect, and allowed patients to use the therapy without getting burned. In fact, if you read the published study closely, Dr. Hamblin’s team makes this point explicitly in saying:
“Because there are ‘quench periods’ (pulse OFF times) following the pulse ON times, pulsed lasers can generate less tissue heating ...This increased power [from lasers] can cause tissue heating at the surface layers [of the skin] and in this instance pulsed light could be very useful."
In short, pulsing works because it allows the skin to cool between laser blasts while maintaining all the benefits the exposure provides.
Modern LEDs: All the Benefits Without the Drawbacks
Fast forward to present day, and LEDs have surpassed lasers as the go-to technology for light therapy. Far from the low-output bulbs of the early 2000s, modern LEDs can produce powerful light waves while pinpointing the perfect wavelengths for almost any use.
See, lasers and LEDS interact with the body in fundamentally different ways. Both use high-powered bulbs, and both can target beneficial wavelengths—but lasers happen to come with a burn hazard.
Lasers burn because they produce a specific type of light, called coherent. This type of light is extremely efficient at transferring energy, which is why lasers were originally better for therapy than LEDS. But coherent light also generates a tremendous amount of heat.
LEDs, on the other hand, produce incoherent light, which spreads similar, high-powered rays over a larger area, bathing the body in a harmless red glow. That’s part of the reason lasers (with a few niche exceptions) have fallen out of favor: LEDs now penetrate just as deeply into the body, but without any burning or negative side effects.
It’s through this lens of knowledge that we must interpret Dr. Hamblin’s study. Because of this fundamental difference between coherent and incoherent light, his findings simply don’t apply to LED technology. In fact, the best application methods for today’s light therapy devices require steady, continuous application—the exact opposite of the original recommendation.
Here's How You Should Use Red Light Therapy
If you’re not supposed to use pulsed light for your LED panel, what should you do instead? First, understand that the efficacy of your red light depends on three main factors:
- Wavelength; and
- Usage patterns.
Let’s take a quick look at each one.
Higher Irradiance Brings Better Results
Irradiance is a measure of the energy your light produces, so it is the most reliable way to predict how quickly you will get results. In general, the higher the irradiance of the light you use, the better results you’ll see from the therapy.
Other measurements, such as watts, are popular in marketing circles, but they simply measure how much power your device uses—not how much it produces. Some lights are more efficient than others. In fact, a lower wattage light can produce greater irradiance and better results than a relatively high-wattage competing product if it uses more advanced technology.
If you’re considering two or more devices, make sure the irradiance reading for both is measured using a standard process. Results change based on how far a measurement device is from each light, so it’s important to stay consistent. For example, here at PlatinumLED, we measure irradiance at a distance of 12 inches from the front of our panels, to make sure the results are consistent with what you’d experience in real-world usage.
NIR and Red Light Are Best for Light Therapy
Also essential is making sure you’re using the correct wavelengths. Longer wavelengths penetrate further into the skin, with red and near-infrared (NIR) light—or, light with wavelengths close to 660nm (nanometers) and 850nm, respectively—providing the best results for most ailments and conditions.
By the way, the 660nm and 850nm wavelengths are exactly what we target with our patent-pending, R+|NIR+ multi-wave spectrum. Check out our product page to learn more.
Consistency Is Key
Finally, make sure to stay consistent and always use continuous wave application. Although the exact amount of time you should spend on light therapy depends on what you’re using it for, it’s important to use the therapy consistently, on a weekly or even daily basis.
For general health and wellness, it’s a solid idea to start with about 20 minutes of exposure per day. Continue that for a week or two, and then make adjustments based on the results you’re seeing and your personal goals. For noticeable results, use the light for at least 10 minutes, but don’t exceed 30 to 40 minutes or you may experience minor inflammation.
The Bottom Line: Don't Use Pulsing for LEDs
While pulsing has become something of a trend, don’t fall for this flashy new application method. It was created for the world of laser therapy, and that’s where it should stay. If you’re using an LED panel, continuous, steady usage will yield the best results.
If you want to improve overall wellness, or treat common health or aesthetic conditions, LEDs are almost always the best choice. Just make sure to stay consistent, use continuous wave application, and purchase a high-quality device like our PlatinumLED BIO or BIOMAX Series. When you do, you’re sure to reap the benefits of light therapy naturally, safely, quickly, and without any fear of negative side effects.