The fifteen days after a botulinum toxin treatment
The session takes a few minutes. What happens next, day after day, is less well known. Here is what to expect, what is normal, and what should make you call.
Dr Selim Zengin, general practitioner, INAMI 1-07696-83-003
Published · Updated · 3 min read
On the day
Right after the injections, small bumps sometimes mark the points for about twenty minutes. A small bruise is possible, especially if you take aspirin or an anticoagulant. You can go back to your usual activities.
The classic advice for the first hours (do not massage the area, avoid intense exercise, saunas and bending forward) is mostly based on caution: no clinical trial has tested it. A series of more than 5,000 patients, with a single ten-minute precaution, reported few side effects, but without a comparison group. I still give you this advice for the first day: it costs nothing.
Days 2 to 5
The effect usually starts after two to three days. The muscle relaxes gradually: frowning becomes harder, without the face freezing. A slight feeling of heaviness on the forehead is possible in the first days, and goes away on its own. A passing headache is one of the common effects.
Around day 15: the check-up
The result is largely in place after about two weeks, even though the product information places the peak effect around the first month. This is the right time for a check-up: we take the same photographs again, in the same conditions, and compare them with those of the first session.
A small adjustment can then be decided, for example if one side responded less or if an eyebrow sits too high. The check-up also tells us whether the dose was right, for next time. Before two weeks, we would be judging an incomplete effect, at the risk of correcting something that would have settled on its own.
Rare, but worth knowing
A drooping eyelid or eyebrow can occur, usually in the days after the session. It is uncommon and temporary; mention it at the check-up, or sooner if it bothers you. An eyebrow that lifts too sharply at the tail can usually be corrected with a small additional injection.
And after that
The effect lasts three to four months on average. The muscle then gradually regains its activity: nothing sags when the effect wears off, the face simply returns to how it was before. A new session is not done before three months, as the product information requires, to limit the risk of the body becoming immune to the product.
Sources.
- Small R. Botulinum toxin injection for facial wrinkles. American Family Physician, 2014;90(3):168-175.
- Summary of product characteristics of a botulinum toxin type A authorised for glabellar lines (French public medicines database, ANSM).
- Santorelli A et al. Toxins, 2025;17(8):372 (series of 5,014 patients, ten-minute precaution).
Related treatments.
General information article. It does not replace a consultation.