Review: Goodnighties Sleepwear

Last month we wrote a post on Goodnighties. Somewhat snarky in tone, we felt the medical claims on the manufacturer’s website were lacking. The company contacted us, and in show of standing up for their product, sent us a sample to try out. We had our interns test out some of their scientific claims and review their literature. We also had a person with relevant night sweat issues review the product (here at Medgadget we like to be thorough). The full results are below, but a condensed version is that we still don’t think much of their claims about “negative ions” in the fabric. However, the reviewer with night sweats did report that the sleepwear did seem to decrease the length of her nocturnal hot flashes (but not the frequency) and she was able to wear them all night.
A recently new sleepwear product, using the science of ionization to offer users a more comfortable and restorative sleep, has made a push into the consumer market for women. The “Goodnighties” sleepwear claims to utilize the patented “IonX” that saturates the fabric with negative ions, advertised to be “more than 20 times the level found anywhere in nature”, allowing sleepers to reap the benefits. What are these benefits? Apparently, wearing Goodnighties sleepwear will improve the flow of oxygenated blood, speed muscle recovery, reduce aches and pains, and wick away moisture from night sweats and hot flashes — all through the benefits of the negative ions in the fabric. Skeptical? So are we.
Literature Review and Quantitative Testing
According to their marketing material, Goodnighties contain negative ions “permanently built into the fabric fibers.” So what exactly are these negative ions with the acclaimed benefits? According to Dr. Albert Ouimet, the leading scientist and part of the original IonX development team, “ions are either atoms or clusters of atoms that contain a negative or positive charge.” Therefore it seems reasonable to believe there would be a built up of negative charge on the sleepwear. And as we know from basic science, anything with a charge will attract the opposite charge. So Goodnighties, if they have more negative ions, should be attracting positive particles, or discharge when it comes in contact with, say, the ground. However Goodnighties claims the fabric to be “static-free” and “non-binding,” a little counterintuitive.
To test for a charge on Goodnighties fabric, a homemade electroscope, built from a glass jar with a cardboard lid, a long metal bolt through the top and two aluminum foil leaves attached to the end, was used. The device did not detect a charge on the fabric, but was able to detect a balloon that was charged by rubbing it against the hair on a person’s head. We could assume the device was not sensitive enough to pick up the charge on the fabric; however, when a voltmeter was used to measure the potential difference between Goodnighties sleepwear and the ground, no considerable difference was measured either.
But let’s say Goodnighties was able to saturate their fabric with negative ions and keep the material static-free, what exactly is the technology behind this sleepwear? That’s the thing — we don’t know, and they don’t specifically say. Goodnighties provides 20+ pages of research that show the benefits of negative ions. But the peer-reviewed research referenced only discusses benefits of negative ions in the air, no mention of those found in fabrics. The references dealing with fabrics all seem to come from the company, those affiliated with it, or non-peer reviewed articles. They go on to list the countless positive effects negative ions have on the body, but fail to mention precisely how their product delivers these ions to the body, or how negative ions in fabric react with positive ions in the body.
As to their claim that “Goodnighties has more than 20 times the level of negative ions found anywhere in nature,” in their research we came across this information they provided:
Number of Negative Ions/sq cm
Clear Mountain Air – 2500
At the Ocean – 5000
IonX Treated Fabrics – 8000
Doing the math on the smaller number gives 2500×20=50,000 which is many times larger than 8,000. This isn’t something we tested, but even by Goodnighties own claims, IonX falls short of having 20 times more negative ions than that found in nature.
In search of some answers, we called the number listed on the website for “Product Questions” and spoke to Marcia, who informed us “the negative ions are absorbed into your body from the fabric.” Let’s think about this. If the negative ions are absorbed into the body wouldn’t Goodnighties eventually lose all its ions, thus making it useless? Marcia didn’t seem to know the answer either, but mentioned “you can wash it about 50 times” before Goodnighties apparently runs out. So what prevents all the negative ions from leaving the fabric before it reaches to your doorstep? And if the negative ions were leaving, the fabric would then be neutral or have a net positive charge. But the real head scratcher is how can the negative ions be absorbed into the body in the first place if Goodnighties advertises the negative ions to be “permanently built into the fabric fibers?” Marcia’s response, which she seemed to fall back to a lot during the conversation, was “I’m not quite sure what you’re asking” or “I’m not sure, but” and then go one to recite personal testimonials.
Goodnighties is also claimed to allow the user to “enter a REM sleeping state quicker and stay there longer.” But athletes supposedly use the IonX fabric as a stimulus to enhance physical performance. How then is Goodnighties supposed to do the opposite and provide a “more peaceful sleep?” Once again Marcia’s response was “I’m not sure.”
Let’s just again give Goodnighties the benefit of the doubt. Assume the fabric has negative ions that somehow enter the body, despite being permanently built into it, and maintains it’s static free and non-cling qualities, it is then claimed Goodnighties will improve flow of oxygenated blood. Using an ultrasound we were able to measure the profusion in a radial artery at the wrist to test this claim. Comparing the flow volume with and without wearing Goodnighties gave the following results:
Flow volume measured using ultrasound Trial 1 Trial 2
Wearing regular cotton clothes 33.90ml/min 31.57ml/min
Wearing Goodnighties sleepwear 33.19ml/min 30.94ml/min
The measurements were taken by two undergraduate students, none of who are professional ultrasonographers so errors may be present, however the data does not show a large difference in blood flow when wearing Goodnighties.
There is a possibility that Goodnighties could provide its users with a more comfortable sleep through its wicking properties. However the claims of Goodnighties being able to provide the body with negative ions through it’s saturated material while still maintaining a neutral charge seems less likely. The overall vague information provided leaves us skeptics of Goodnighties.
2 Night Sleep Test
To test the base claims Goodnighties makes about the ability of their product to improve a night sleep of a person with night sweats we were provided with a Three Quarter Sleeve Top Style 805 and Crop Pant Style 809 by Goodnighties. These were given to an early 50s post-menopausal woman who experiences nightly (3-4 episodes/night) night sweats of ~60 sec duration, leading her to sleep most nights naked in a pool of sweat regardless of the temperature. Over two nights wearing the sleepwear she reported that while the frequency of sweating episodes was unchanged, they were much shorter, lasting only 15 seconds instead of 60. She was able to wear the sleepwear all night the second night and plans on continuing to wear at least the top in the future. When informed of the list price of the sleepwear (~$65 for both pieces) she said she probably would not have purchased them at that price but maybe $20 cheaper. Having slept in them she was interested in purchasing a blanket or sheet made of the material rather than a garment.
Conclusion
We stand by our original post in that we still don’t think much of their claims about “negative ions” in the fabric. However, the reviewer who had an issue with night sweats did report that the sleepwear did seem to decrease the length of her nocturnal hot flashes (but not the frequency) and she was able to wear them all night. We think this is probably due to the wiking action of the fabric. So if you know someone who complains about post-menopausal night sweats this may be something they want to try, however it probably isn’t due to the power of negative ions.
The ionic testing and literature reviewed was done by Medgadget interns Jim Moriarty a student at UMass-Amherst and Janet Lin a student at MIT. Thanks to our reviewer who had night sweats and was willing to try out the sleepwear.
Previously: Use the Power of Negative Ions to Sleep Better?
Product page: Goodnighties…