Eyebrow problems after Botox: height or asymmetry

The eyebrows frame the eyes: a slight change in their height is enough to alter facial expression. They are rarely injected for their own sake, but they react to injections given just above, in the forehead, or right next to them, between the eyebrows. This page is part of our atlas of problems after a botulinum toxin injection, organised area by area.

What problems can affect the eyebrows?

Three situations are described. The eyebrow raised at the tail, often called the "Spock brow", corresponds to what the labels call the Mephisto sign: an elevation of the outer part of the eyebrow^1,3. The drooping eyebrow, or brow ptosis, gives a heavier look^1,2. Finally, uneven eyebrows leave one eyebrow higher than the other; facial asymmetry is described among the uncommon effects of one type A toxin².

After treatment of the forehead combined with frown lines, one label classes a drooping eyebrow and the Mephisto sign as common¹. In these trials, a drooping eyebrow appeared a median of 5 days after treatment¹. For the short-acting botulinum toxin (serotype E), approved only for frown lines, the label reports a drooping eyebrow in 0.13% of patients and a Mephisto sign in 0.04%³. As of 9 October 2026, this toxin is approved in the European Union and Canada^5,6. These frequencies come from different trials and cannot be compared.

Each page details the cause, when it appears, how long it lasts and what can help. Some pages are also listed in the forehead and frown line areas, because the injection involved may have been given there.

Which signs mean you should see a doctor quickly?

An eyebrow that is too high or too low is bothersome but not dangerous: it returns to its position as the effect of the toxin wears off. See a doctor promptly if the eyebrow or eyelid droops enough to get in the way of your vision, or if your vision is blurred or double^1,2. Any difficulty swallowing, speaking or breathing means calling emergency services (15 or 112 in France, or your local emergency number): these are the rare signs of the toxin spreading away from the injection site³.

For the doctor, it helps to note the date of the injection, the areas treated and the day you noticed the change.

Why are injections given near the eyebrows?

The eyebrow is pulled up by the forehead muscle and down by the muscles between the eyebrows and around the eye. By relaxing some of the muscles that pull it down, a slight lift can be obtained: in a small study of seven women, five had a lift of 1 to 3 mm, about 1 mm on average⁴. This lift is not among the aesthetic indications of the French labels, which are limited to frown lines, crow’s feet and forehead lines depending on the product^1,2: it is an off-label use, to be discussed with your doctor. To find out why and how an eyebrow can be lifted, see the page for this area in our atlas of treatment areas.

If the change in your eyebrows followed a forehead injection, the page on forehead problems after an injection may also concern you; if it followed an injection between the eyebrows, see the page on what can follow a frown line injection.