Jawline · Fact-check
Does mewing actually work? The honest answer.
Mewing has millions of views and a simple promise: hold your tongue against the roof of your mouth and your jawline sharpens over time. Here's what's actually true, what isn't, and what our own scoring rubric says about it.
The short answer
No - not for an adult jaw. By adulthood, facial bone is fused; it doesn't remodel in response to tongue pressure. The orthodontic research mewing borrows its credibility from studied growing children, whose jaws can still respond to sustained oral posture - that mechanism doesn't carry over once bone growth is complete.
Tongue posture can genuinely affect breathing and general oral posture, and better posture overall can change how a jawline photographs. What it can't do is change the shape of the bone underneath.
What people are actually seeing when "mewing works"
Most before-and-afters credited to mewing have a simpler explanation: weight loss revealing a jawline that was always there, less puffiness from better sleep or hydration, or just a better camera angle and posture in the "after" photo. None of those are tongue posture doing the work - they're changes to fat, fluid, and framing.
That's not a coincidence. It's exactly the set of things that do respond to habits, which is the whole point of the next section.
What's actually controllable here
Our own scoring rubric tags every sub-factor as Movable, Partly movable, or Structural - see /methodology for the full breakdown. Jaw contour (the underlying bone shape) is Structural: locked, and it contributes zero to your potential score, because no habit changes it.
Under-chin fullness is a separate sub-factor, and it's Movable - it responds to body-fat percentage and hydration. That's why a more defined-looking jaw usually follows fat loss and better hydration habits, not tongue exercises.
So what should you actually do
If the goal is a sharper-looking jawline: body composition and hydration move the submental (under-chin) sub-factor, consistent grooming moves how even the jaw and jawline read, and consistent sleep reduces the puffiness that makes any jawline look softer than it is.
None of that requires holding your tongue anywhere for 10 hours a day.
Why we score it this way
Most content in this space either oversells ("yes, it works") or dismisses the whole category outright. We built our scoring to do neither: score what's real, tag what isn't fixable, and never promise a number we can't back with a mechanism.
That's also why our potential score can't be inflated by chasing a structural sub-factor - see /methodology for exactly how Movable, Partly, and Structural sub-factors are weighted.
See which of your 16 sub-factors are actually movable
Take the free quiz, then get scored against the same Movable / Partly / Structural rubric described above - with a 90-day protocol built around what's actually within your control.
Start the quiz →