Botulinum toxin: at what age should you start?

Two kinds of lines

A dynamic line only appears when the muscle contracts: when you frown, raise your forehead or smile. A static line stays visible at rest. Over the years, the same movements repeated and the thinning of the skin gradually turn some dynamic lines into static ones.

Botulinum toxin acts on the muscle: it relaxes it for a few months. It is therefore mainly effective on dynamic lines. On a line already etched at rest, it often softens it without erasing it. The product information says so too: when a line comes mainly from the skin losing elasticity (age, sun), toxin alone may not be enough.

What the product information says

Botulinum toxins authorised for frown lines are authorised in adults. They are not recommended before 18, and several product leaflets restrict them to adults under 65, for lack of sufficient data beyond. They also require at least three months between two sessions.

In other words, the official framework sets no age to start within adult life. The examination decides, not the date of birth.

What about "preventive" toxin?

You often hear that you should start early, around 25, to stop lines from settling in. The idea has a logic: a muscle that works less marks the skin less. But the evidence remains thin.

The most quoted argument comes from two identical twins followed for thirteen years: the one who had regular injections had fewer lines at rest than her sister. It is an interesting observation, but it concerns two people. A study over three treatment cycles also showed a gradual improvement of frown lines at rest, but over one year. A review published in 2023 on adults under 41 concluded that good-quality studies are lacking.

My position: starting in order to prevent only makes sense if a marked dynamic line is already there, if it truly bothers you, and with measured doses. I do not treat a face that does not need it.

Good reasons to come for a consultation

• An expression line bothers you every day, for example a frown that makes you look stern or tired.
• A line is starting to stay visible at rest.
• You want a medical opinion before deciding, even if the answer is to wait.

When we do not treat

Botulinum toxin is not used in neuromuscular disease such as myasthenia gravis, with an infection or inflammation where it would be injected, or during pregnancy and breastfeeding. Some injectable antibiotics (aminoglycosides) can strengthen its effect. These points are checked at every consultation.

Another situation deserves to be mentioned: when worry about a line becomes overwhelming, out of proportion to what others see. An injection then rarely brings the relief expected, and it is better to talk about it openly.

How I work

The first consultation starts with an examination and a computer analysis of your face. We look at the muscle in motion and at rest. If treatment is useful, the dose is chosen to keep your expressions. We then meet again about fifteen days later to measure the result on the same photographs.