Would You Give Up $600 and 20 Minutes for a Perfect Jawline?

It was a regular Tuesday in August 2023 when Siena Gagliano made a split-second decision to change the shape of her jaw. A viral before-and-after video documenting an aesthetic treatment that took an influencer’s face from boxy and bulked-out to slim and heart-shaped had flashed across her screen. Forty-eight hours and $600 later, Gagliano and her numbed-up face sat in a medspa leather recliner, patiently awaiting the same procedure.

She didn’t view the neurotoxin injections she was about to receive in her jaw muscle (the masseter muscle, in official terms) as a Super Big Deal. Though none of the five available neurotoxins on the U.S. market—Botox, Xeomin, Jeuveau, Daxxify, and Dysport—are currently FDA-approved for use on the jaw, the 25-year-old writer had “heard so many good things” about the off-label treatment, which works by relaxing the overworked muscle and, in turn, slims down the area between the bone and skin.

At first, the treatment was a 10 out of 10. Gagliano’s side profile looked completely different, and she could feel the muscles getting flatter. “I had lost a little bit of weight, but have always had a square jaw, so I was really excited when the injections started to give me that Megan Fox, Bella Hadid slimmed jawline,” she says.

But fast-forward eight months, and her jaw didn’t look like that of an influencer on Instagram. Gagliano had jowls. “Think of your jaw like a table and the skin like a tablecloth. If the table gets smaller—meaning that the muscle shrinks with Botox—and the tablecloth stays the same, you end up with a draping tablecloth,” says Michelle Henry, M.D., a board-certified dermatologist and founder of Skin Aesthetic Surgery of Manhattan. It’s ironic, but when jawline injections don’t go according to plan, patients like Gagliano can end up with the antithesis of what they wanted.

Courtesy of an onslaught of aesthetic innovations, the jawline you’re born with is just a suggestion. For years, procedures like V-line surgery, which involves shaving the jaw bone, or Kybella, a fat-destroying injection, dominated the discourse, with price and exclusivity doubling as deterrents. Cut to present day, and the options for slimming the face—some based on logic, others on lore—are pushed into the cultural zeitgeist with the same level of nonchalance as Hailey Bieber’s nail trend of the week.

There’s Ozempic (and all the faux-zempics), of course. And while overall weight loss is largely the goal when taking the medication, yes, the jawline slims too. More specific to the mandible: mouth taping during sleep, buccal massage, microcurrent devices, non-invasive skin-lifting procedures, and ultrasound facials that encourage collagen production. All promising a path to a sleeker jaw.

Yet masseter injections have received the most hyped-up reputation as a quick-hit solution for a slimmer jawline. As Catherine Chang, M.D., a board-certified plastic and reconstructive surgeon and founder of Privé Beverly Hills, explains: “Masseter Botox has always been something that we’ve done. But with the combination of people being more open about what they’ve had done, the reach of social media, and its migration into medspas, [it’s become a more requested treatment].” It’s also readily available, and a lot cheaper than more invasive options like jaw surgery and liposuction.

The internet, your next-door neighbor, and insert-alleged-celebrity-here would have you believe that popping neurotoxin into the jaw in exchange for slimming, defining benefits is as simple and ubiquitous as an ATM transaction. It doesn’t require dietary changes or sweat sessions at the gym. There’s no need to retrain how you sleep, incorporate daily beauty devices (consistency is key!), or get a little nip-tuck. With no downtime and a couple hundred dollars, masseter injections are portrayed as a FastPass to the jaws of our dreams—and, unfortunately, the ease overshadows the fine print. But Gagliano is proof that side effects do happen.

Jowling. Draping. Puckering. All words to describe the not-so-talked-about consequence that can occur when jaw injections are given to the wrong candidate. There’s no hard-and-fast checklist to see if you will achieve masseter-injection success. Still, a skilled provider—namely a board-certified dermatologist or plastic surgeon—will have the foresight to make an informed recommendation.

“The bone sets the tone,” says Renata Khelemsky, M.D., a double board-certified facial plastic surgeon and founder of Renata Facial Cosmetic Surgery in Brooklyn, New York. “Think of your jawbone like a hanger for a winter jacket. That jacket is going to look fantastic on a big, wooden hanger. But put it on a pediatric hanger? It’s going to be all loosey-goosey and drape weird.” And facial structure isn’t the sole predictor of success. Skin laxity naturally declines with age and plays an equally important role. You can check all the boxes, but if your skin doesn’t have the snap-back quality necessary, things will (literally) go south.

“It depends on what aging stage they’re in, but I’ve had girls in their 30s and 40s with this premature sagging—primarily when they don’t have a strong jawline,” says Melinda A. Farina, a renowned aesthetic concierge who has completed 64,000 consultations via her multi-national consultancy, Beauty Brokers Inc. One 35-year-old patient of Farina’s had such extreme jowling post-masseter injections that she decided to get a mini facelift.

In a world where training is relatively cheap and easily accessible—any nurse practitioner or physician assistant can give a masseter injection after paying a few thousand dollars for a weekend course—an experienced operator with the determination to say “no” is not guaranteed. “It takes many, many years and thousands and thousands of hours to make this look easy,” Dr. Henry says.

The jowling discourse isn’t designed to fearmonger. It’s not to talk you out of having jaw injections, either. "Masseter botox is such a unique tool in our kit when done with proper dosage and with the right candidate,” says Pooja Rambhia, M.D., a board-certified dermatologist at UnionDerm in Greenwich, Connecticut.

But it is a reminder that while our feeds may paint getting injections as something as simple as applying a filter, any tweak we make to our bodies—no matter how subtle—can come with side effects that might be less so.

Gagliano stopped getting injections and “thankfully, my skin snapped back,” she says. Her jowls eventually disappeared; her “square” jawline returned. And with it, a sense of relief.

This article appears in Marie Claire's 2025 Craftsmanship Issue.