Health3 min(s) read
Published 13:11 06 May 2026 GMT
Update on doctor who injected just one half of her face with Botox to show what it does to you
A doctor who once experimented by injecting Botox into only one side of her face has repeated the unusual test to show the effects again.
Dr. Bita Farrell, a board-certified physician with more than two decades of experience, previously used herself as a “lab rat” to demonstrate how the treatment works.
Rather than opting for a full-face procedure, she injected just one side and documented the results for her audience.
Dr Bita's initial experiment with botox
In her first viral video, filmed two weeks after the injections, she explained: “Now for you, two weeks later, I present my results as I try and contract my lower face muscles.” The difference was striking — the untreated side of her face appeared far more expressive, while the injected side barely moved.
Pointing out the contrast, she said: “You can see that the platysma muscle on this [left] side is really contracting and pulling my jawline down, and so is my DAO, pulling the corner of my mouth down.” Referring to the treated side, she added: “I’m really trying to pull this side!”
She also highlighted subtle changes, noting: “See that this cheek rides a bit higher, this nasal labial fold seems softer and so does my shadow at the marionette on this side.”
Explaining the science behind it, she wrote: “Muscles of the face either pull up or pull down.” When the downward-pulling muscles are relaxed with Botox, “the muscle that pulls the mid face up… dominates and pulls the face up!” According to her, this can help reduce signs of ageing and create a lifted appearance.
Although the results typically last a few months, Dr. Farrell later evened things out by treating the other side.
Dr Bita's face update
Around a year and a half later, she repeated the experiment to further demonstrate the effect of targeting specific facial muscles.
She explained again: “This can help reduce the appearance of mild jowls, soften the downturn at the corners of the mouth, create a neck lift effect (Nefertiti neck lift), sharpen the jawline, and make the cheeks appear slightly fuller and more lifted.”
However, she stressed that it’s not a complete fix for everyone, adding: “Neuromodulators help one component, but they are not a full corrective treatment for moderate to severe jowls.”
Her results showed that the treated side appeared more lifted and fuller higher up, while the untreated side showed more sagging around the jaw.
Viewers were impressed by her willingness to test it on herself, with one person commenting: “This is so educational and you are AMAZING!” Another wrote: “Wow... a doctor willing to show a test comparison on themself? That just gained a lot of my respect. Thank you Doc!” While some were surprised by the outcome, saying: “Un-injected side looked way better! I was surprised when she said the other side. Thanks for the demo!”
Summing up the concept, she said: “To simplify, the muscles of the face are either elevators or depressors.” By relaxing the muscles that pull downward, it allows the lifting muscles to take over, creating a subtle but noticeable lift.