Isabelle Lux, a 32-year-old content creator from Palm Beach, Florida, said she was terrified while sitting in the chair waiting for her ‘Barbie Botox’ — 40 units of the neurotoxin injected into each trapezius, the muscle holding up her neck.

She was looking to slim her shoulders in preparation for her wedding, as well as release some upper back pain. “I was thinking the whole time, ‘If it goes right, this is going to be great and I can’t wait to share it (online). If this goes wrong, I better warn people. So basically I figured no matter what happens, I’m going to tell people.’ And God, I just prayed it went well.”

The procedure was originally devised to aid the release of severely overworked trapezius muscles which could cause migraines and intense neck tension. Now, it’s being administered off-label to cosmetically diminish the size of shoulders, elongating the neck. And it’s gaining traction on social media.

The hashtag ‘Barbie Botox’ currently has over 7 million views on TikTok, where MediSpas and clinics document injecting their clients, adding pastel pink captions and sparkle emojis. Lux’s video detailing her own experience with the treatment has now been viewed more than 250,000 times. She credits herself with coining the phrase. “It came from the idea that you would look more like a Barbie when you get it done, which I don’t think is a bad thing,” she told CNN in a phone interview. “It elongates the neck, slims the shoulders and creates a very delicate physique when it’s done properly.”

However, if administered incorrectly, or at the wrong dosage, the Botox could paralyze the muscle completely, said Dr. Acharya. The neurotoxin can also occasionally migrate from the original injection site, weakening the nerve connection of other surrounding muscles.  “And especially if it’s around the neck, that can be quite significant because it can affect your ability to hold your head up properly.”

Lux — who was gifted the $1,200 treatment by an on-demand booking app for aesthetic services — was told to avoid carrying heavy backpacks, strenuous exercise and massages for at least 72 hours. “I was actually quite scared,” she said. “Once (Botox) is in, there’s nothing you can do to reverse it. In the first week I felt so much actual pain, tension and stiffness in my neck, shoulders and upper back. I was really, really worried.” Two months later, Lux said she feels “better than ever” and is already planning a top-up session in the winter.