Doctor reveals the side effects of Botox after injecting only one side of her face

The impact was significant

"For the sake of science and education and all of you, and myself, I made myself my own lab rat," she told the camera, before explaining how she'd drawn a black line down the middle of her face and administered the neurotoxic protein to the lower half of her right-sided facial muscles.

This included the DAO (depressor anguli oris), which pulls down the mouth's corners, and the platysma, which controls expressions and movement of the mouth.

"Now for you, two weeks later I present my results as I try and contract my lower face muscles," continued Farrell.

As she did so, her untreated left side demonstrated way more muscular flexibility, while her Botox side displayed almost no movement whatsoever.

"You can see that the platysma muscle on this side is really contracting and pulling my jawline down, and so is my DAO, pulling the corner of my mouth down," Farrell pointed out.

Highlighting the right side, she claimed: "I'm really trying to pull this side!"

The doctor also mentioned how the cheek "rides a bit higher", the "nasal labial fold seems softer" and "so does my shadow at the marionette [line]" on her Botoxed side.