Do you have muscle pain? Need to lose weight? How about anxiety or stress? We just got a flyer in the mail promising help for all these things, plus better sleep, increased libido, reduction of cellulite, pain management, a decrease in jet lag, a stronger immune system, fewer wrinkles, and—just to cover all the bases—enhanced mental clarity and “invigoration” of your mind and body. I can’t think of anyone I know who doesn’t suffer from at least one of these issues, including me. Is there something that can help? It seems too good to be true.

Of course it does.

The flyer is advertising whole body cryotherapy (WBC). (This is not the same thing as using liquid nitrogen, for example, to freeze off small skin cancers, or other similar treatments.)

Turns out that this “treatment” involves subjecting oneself to extreme cold for two to four minutes. And by extreme, I’m talking -200 to -300 degrees Fahrenheit. That’s a bit colder than Minnesota in the winter—or even Mars.

There are two types of WBC devices. In one, your body is exposed to the frigid temperatures while your head remains outside the enclosure. In the other, your entire body, including your head, is enclosed. Some hold a single person, others can accommodate several people sitting or standing. The flyer we received shows this picture of a booth full of cold-looking clouds.

Is it really a good idea to spend several minutes at temperatures approaching that of liquid nitrogen?

Being the skeptic that I am, I did some research. I learned that “the FDA has not cleared or approved any of these devices for medical treatment of any specific medical conditions.” That’s because there are no published studies showing that it works for any of the issues advertised.

Moreover, the claims that cold reduces muscle soreness are now in direct opposition to new research that suggests putting ice on a muscle injury does more harm than good. And while using WBC for muscle aches is the most widespread use, especially among professional athletes, the evidence is largely lacking. An article in The Guardian (a British publication) states:

In 2015, a small German study found endurance athletes recovered more quickly and were able to perform better in the second of two running tests separated by an hour if they underwent whole-body cryotherapy in between. A Cochrane review—the gold standard in healthcare evidence—pooled the results of four previous studies involving 64 physically active adults and concluded there was insufficient evidence to support its use to relieve muscle soreness after exercise.

But does WBC help you lose weight? Think about it—You’re not going to burn off that double cheeseburger in three minutes, not matter how cold you are. How about anxiety or stress? Maybe just stopping out for a few minutes can lower your blood pressure, but the world isn’t going away in the meantime. And all those other claims? There is no evidence at all that WBC gives you better sleep, a stronger sex drive, a stronger immune system, or fewer wrinkles,  much less enhanced mental clarity and “invigoration” of your mind and body.

Yes, there are plenty of anecdotes. WBC is growing in popularity. People desperate for relief that their traditional medical providers are not providing swear by it. And it may work. You’ve heard of the placebo effect, right? If you expect something to make you feel better, it often does—because of your expectations.

So let’s say your friend tried it, and is now raving about how she feels so much better. You think, “I might as well try it and see for myself.” It may not help, but hey, it won’t hurt, right?

Maybe.

The FDA is warning that temperatures this low can definitely do harm.

In some devices, liquid nitrogen circulating inside pipes is used to chill the air. But in others, the sudden, extreme cold is created when that liquid nitrogen is released into the small compartment with you. As the nitrogen quickly turns to gas, it displaces the oxygen in the room. This puts you at risk of asphyxiation—a loss of consciousness due to oxygen deprivation.

Additionally, temperatures this low can cause frostbite, “freezer” burns, and can even injure your eyeballs. I don’t know about you, but I highly value my eyeballs!

Then there’s the damage to your bank account. The ad we received in the mail included a special new customer offer—three sessions for “only” $79.  In some places, single treatments can run $100. This may be pennies for a professional athlete, but it’s a significant expense for most of us. (Personally, I’d rather spend it on a massage!)

Finally, if you choose to undergo WBC in place of other treatment, you could be making your condition worse. The FDA strongly recommends checking with your doctor beforehand. If you’re pregnant, or suffer from heart disease or untreated high blood pressure, don’t use the device, period.

Remember the advice your mama gave you: If it seems too good to be true, it probably is.