Experts say the new exercise fad where you chew on a silicone ball can provide some benefits to your jaw, but they say there are a lot of potential problems.

Share on Pinterest A new facial exercise product bills itself as a “noninvasive facelift” that will firm up your facial muscles, define your jawline, and even regrow hair. But is there any proof it does what it claims? If you’ve been on YouTube any time in the past few months, there’s a good chance you’ve seen a catchy ad for Jawzrsize. Touted by owner and inventor Brandon Harris, the product’s pitch is simple: You work out every other muscle in your body, so why not your face? Functionally, the Jawzrsize is pretty straightforward. It’s a silicone ball that molds to your teeth. You simply bite down on it for exercise. The company says the ball offers 40 or more pounds of resistance, depending on which model you’re using. Their recommended routine is 20 to 30 minutes per day, every day. They say you should see changes within 30 minutes. But what — if any — benefits will you see at this point? The product makes a lot of claims, so Healthline contacted two dental and orofacial experts to talk about what to expect from the Jawzrsize. Harris and Jawzrsize didn’t respond to numerous requests for comment for this publication.

Create a well-defined jawline Of all the claims the product makes, this one makes the most sense. “You can work out your jaw, and this will definitely work out your jaw,” said Dr. Parish Sedghizadeh, associate professor of clinical dentistry at the University of Southern California (USC) school of dentistry. Building the jaw muscle, or masseter hypertrophy, can be achieved with the Jawzrsize. However, experts warned that this kind of parafunctional, abnormal jaw activity can actually be detrimental in many ways. Since the jaw and other facial muscles are already worked out during the day through talking, eating, and similar activities, they already endure a certain amount of strain. Parafunctional activities, like chewing gum or using a Jawzrsize, increase the strain on the face and jaw. These should actually be avoided, Sedghizadeh told Healthline, because they have the potential to lead to the development of jaw problems. These include tension headaches, jaw clicking and popping, and injury to the temporomandibular joint (TMJ), the hinge that connects the jaw to the face. Even if you do start putting on jaw muscle, it might not look exactly how you imagined it would. “We don’t have any measure [of] how much muscle you are going to gain,” Dr. Laurel Henderson, resident in orofacial pain and oral medicine at USC, told Healthline. “So, you might actually have a bad aesthetic result from it. You might have more bulk than you wanted… like football player neck.”

Toning and rejuvenating the face Both Henderson and Sedghizadeh were skeptical of the claims that Jawzrsize could tone and youthen the face. The chewing motion, they said, actually only works “a very limited set of masticatory muscles.” “It’s not working eyebrow muscles or things that result in facial wrinkles,” said Sedghizadeh. “You’re not going to suddenly get this Botox or toned face just because you’re bringing your jaw up and down.” Despite Harris’s insistence that the product floods the face, brain, and scalp with blood and oxygen, the experts said there’s no real scientific data to support his claims that this results in hair growth or facial rejuvenation. “There is no evidence that this does anything,” said Henderson. “We practice evidence-based dentistry first and foremost and we use evidence for what is going to happen in the face. So, we don’t like to give anything to our patients that we don’t know what is going to happen to them.”

‘Slimming’ of the face First of all, “spot training” for fat isn’t possible, the experts said. So, using the Jawzrsize won’t actually decrease the amount of fat on your face. “You can build up the muscle in the area, but you may not see it if there is a fat layer on top of it,” said Henderson. However, the chewing motion used on the product will stimulate the metabolism in other ways, for better or worse. Chewing does actually burn calories — not many — but your body is using resources to do it. But chewing also has larger effects on the body by “tricking” it into thinking that it’s eating when it actually isn’t. Chewing can stimulate increased stomach acid production. Non-nutritive chewing, as it’s called by dentists, “is a problem for the GI system, and can cause gastritis, acid reflux, and stomach upset problems,” said Henderson.