No, mewing does not change the size of your lips.
While mewing, the technique of correcting tongue posture, is claimed to have various benefits, including improved facial structure, it will not alter lip size. According to the reference material, lip size can only be changed through cosmetic treatments.
What Mewing Might Affect Around the Lips
Although it doesn't change lip size, proponents of mewing suggest potential benefits, including an improved lip shape. The reference material confirms that improved lip shape can be a potential benefit with mewing.
Lip Size Changes
To reiterate and emphasize, lip size adjustments require cosmetic intervention. Mewing won't make your lips bigger or smaller.
