Rumour: “Botulinum toxin (commonly called ‘botox’) makes your face look frozen” — What does the science say?

Short answer: No, botulinum toxin does not by itself make the face look frozen. When an appropriate dose is injected at the right points, the aim is to soften certain wrinkles while preserving your facial expressions. A frozen look is mostly linked to a higher dose than needed, treatment of a large area or planning that was not tailored to the individual, and its effect is temporary.

How does botulinum toxin work?

Botulinum toxin temporarily reduces the “contract” signal that travels from the nerve to the muscle. As a result, the injected muscle contracts less, and the wrinkles caused by that muscle's movement (for example frown lines between the eyebrows, forehead lines or lines at the corners of the eyes) soften.

The effect is seen only in the injected muscles and their immediate surroundings. Our face has many muscles that create expressions; treatment is usually applied to only a few of them. This is why, in a well-planned treatment, expressions such as smiling, raising your eyebrows or looking surprised are preserved; only the lines that form during these expressions become less noticeable.

When does a “frozen” look occur?

In some people, the face looks expressionless or “mask-like” after treatment. This is generally thought to be linked to the following reasons:

• Using a higher dose than needed for the person's muscle strength and needs
• Treating a very large area with a great many injection points
• Leaving the forehead muscle completely immobile; this can sometimes also cause a feeling of heaviness or drooping of the eyebrows
• Applying a standard scheme without assessing the person's facial structure, expressions and expectations
• The product spreading beyond the target muscle

Some people, on the other hand, deliberately want a more pronounced effect. In other words, whether the look is “frozen” or “natural” depends largely on the planning done at the consultation and on your expectations.

Why do the dose and injection points matter?

The effect of botulinum toxin depends on the dose: a lower dose partly relaxes the muscle, while a higher dose reduces movement more. Muscle strength varies from person to person; for example, men's facial muscles are generally stronger. This is why a single “standard dose” does not give everyone the same result.

The location and depth of the injection points also affect the result. Injections at different points within the same area can create a different expression. For example, the position of the eyebrow can change depending on which points of the forehead muscle are injected. These details show why it is important for the treatment to be performed by a physician who knows facial anatomy well.

How is a natural result planned?

For a natural result, the most important step is an open conversation with your physician at the consultation. It may be helpful to discuss the following:

• Which lines bother you and which of your expressions you want to keep
• How important your facial expressions are for your job or daily life
• If it is your first time, starting with a more moderate dose and, if needed, reassessing at a follow-up visit
• What you liked and did not like about any treatments you have had before

The effect usually starts within a few days, and the full result is seen within a few weeks. This is why it is better to assess the result not in the first days, but at the follow-up time your physician recommends.

If a frozen look occurs, will it go away?

Yes. The effect of botulinum toxin is temporary, and muscle movement returns over time. The effect usually lasts about 3–4 months; this can vary depending on the person, the area and the dose. If you are not happy with the result, it is advisable to talk to the physician who performed the treatment and ask for the next treatment to be planned accordingly.

Symptoms such as marked drooping of the eyelid, double vision, or difficulty swallowing or breathing are not a “frozen look”, however; these are situations that require immediate medical assessment. If you have any of these symptoms, call 112 (or your local emergency number) without delay.

Conclusion

The myth that “botulinum toxin makes your face look frozen” arose from the visible results of some treatments performed with a higher dose than needed or with planning that did not suit the individual. However, this is not an inevitable result of the treatment. For more detailed information, see our article «Botulinum Toxin (Commonly Called “botox”): What It Is, Who It Suits and What to Watch For».