Most people searching for masseter Botox in Toronto are looking for one of three things: a softer, less square jawline; improved facial symmetry; or both. The masseter is the thick muscle at the corner of your jaw that does the work of chewing — and in many people, it has been working overtime for years. Neuromodulator treatment reduces its activity, and over several weeks the muscle softens and, with repeat treatments, gradually slims.
At Toronto Beauty Nurse, I use Dysport — not Botox — for this treatment. Dysport is my preferred neuromodulator for the masseter because of how it spreads and integrates in a larger muscle mass. The results are the same elegant outcome patients search for; the product choice reflects my clinical preference and training. A consultation is required before your first treatment.
Real patients treated at Toronto Beauty Nurse with the masseter Dysport protocol. → Read the full clinical journal entry: Working in the Grey
[ Before / after photo — set 1 ]
[ Before / after photo — set 2 ]
The Treatment
Dysport is a neuromodulator — it works by temporarily reducing the nerve signal to the masseter muscle, causing it to relax and, over time, to atrophy. Unlike filler, which adds volume, this treatment removes bulk by letting an overworked muscle rest.
The masseter responds to this reduction in two ways. In the short term, the muscle relaxes and the jaw feels less tight. Over months of reduced activity, the muscle mass itself decreases, narrowing the lower face and softening a wide or square jaw.
The dosing arc matters more than people realise. A very high dose given all at once can cause a sudden drop in jaw width that looks unnatural, or temporarily affect chewing strength. My approach is to treat in a considered, graduated way — particularly for first-time patients — so the change happens gradually and keeps pace with your face.
MECHANISM: neuromodulator-induced muscle relaxation and atrophy
PRODUCT: Dysport (abobotulinumtoxinA)
ONSET: results begin at 2 to 4 weeks, full effect at 6 to 8 weeks
The appointment itself is brief. After your assessment, I mark the injection points and treat each side of the jaw with a series of small injections into the body of the masseter. The needle is fine and most patients describe the sensation as a quick pinch — discomfort is minimal and there is no numbing cream required.
The whole treatment takes about fifteen to twenty minutes. You can return to your normal day immediately afterwards.
You will not see a dramatic change overnight. The Dysport begins working over the first few days as the muscle relaxes, and the visible slimming effect builds over the following weeks as the muscle gradually reduces in bulk. Expect to see meaningful change at six to eight weeks.
SESSION LENGTH: 15 to 20 minutes
DOWNTIME: none — you can return to normal activities immediately
VISIBLE CHANGE: gradual, building over 6 to 8 weeks
DISCOMFORT: minimal; no numbing required
For jaw slimming, most patients see results lasting four to six months from a first treatment. With repeat treatments over one to two years, the muscle maintains a reduced resting size and the intervals between treatments often extend — some long-term patients maintain results with treatment twice a year rather than three or four times.
Results are not permanent. If you stop treatment, the muscle will gradually return to its original size. This is by design — it is a reversible, adjustable treatment that I can dial up or down based on your response.
DURATION: 4 to 6 months (first treatment), often longer with repeat sessions
MAINTENANCE: 2 to 4 treatments per year initially; may reduce over time
symptom relief often noticeable within 2 to 4 weeks
REVERSIBLE: yes — muscle recovers fully if treatment stops
Masseter Dysport is suitable for a wide range of patients. You may be a good candidate if you want a softer lower facial contour, if you are self-conscious about a wide or square jaw.
It is worth knowing that this is not a weight-loss treatment and it does not change bone structure — it reduces muscle bulk only. For patients whose wide jaw is primarily skeletal, I will tell you honestly at consultation that the effect will be limited, rather than oversell a result that is not achievable.
There are some situations where I would not treat. Pregnancy and breastfeeding are absolute contraindications. Active infection or skin breakdown at the injection site requires deferral. A small number of people have neuromuscular conditions that affect how neuromodulators work, and anyone with a known hypersensitivity to Dysport or its components should not receive treatment.
GOOD CANDIDATES: wide or square jaw (muscle-related), visible masseter enlargement, facial asymmetry
HONEST LIMIT: does not change bone — skeletal jaw width is not addressable
NOT SUITABLE: pregnancy, breastfeeding, active infection, relevant neuromuscular conditions
CONSULTATION REQUIRED: always, before first treatment
Aftercare for masseter Dysport is minimal. There is no downtime, but there are a few simple things to keep in mind in the first four hours after treatment.
Avoid lying flat, doing strenuous exercise, or applying heat (saunas, hot yoga) for four hours post-treatment. Do not massage or press firmly on the injection sites. These precautions help keep the product localised to the masseter and reduce the small theoretical risk of it migrating to nearby muscles.
Some patients notice mild tenderness or bruising at the injection sites for a day or two — this is normal and resolves on its own. Very occasionally, patients notice a slight asymmetry in the first few weeks as each side responds at a slightly different rate; this typically self-corrects by the six-week mark, and I will assess this at your follow-up.
A follow-up is recommended at six to eight weeks so I can assess your response, check symmetry, and plan your next session if needed.
FIRST 4 HOURS: no lying flat, no exercise, no heat, no massage at injection sites
BRUISING: possible, resolves within a few days
ASYMMETRY: may occur early — typically self-corrects by week 6
FOLLOW-UP: recommended at 6 to 8 weeks