Botulinum Toxin — Four Different Jobs, One Injectable

How It Works

Botulinum toxin temporarily reduces the signal reaching a muscle or gland. Because the target and the depth determine the outcome, the same product is used for very different purposes: softening expression lines (forehead, glabella, crow's feet), reducing muscle bulk (masseter, trapezius), and surface skin conditioning.

The variables that matter are dose, depth and precise placement, all of which follow from anatomy. This is the reason results differ so widely between injectors using identical product.

By Area

Skin botox — superficial micro-injection

Very small quantities placed close to the skin surface, aiming at pores, oiliness, texture and fine lines. Deliberately shallow so that expression is not significantly affected.

Masseter — square jaw

Reduces the action of an over-developed chewing muscle, softening the jaw contour over the following weeks. Also considered where clenching or grinding is present. Bulk returns gradually as function recovers, so repetition is expected.

Salivary gland

Reduces the volume of enlarged salivary glands to refine the lower facial contour. Sometimes planned alongside masseter treatment when both contribute to a wide lower face.

Trapezius

Reduces bulk in an over-developed trapezius, aiming at a longer-looking neck and shoulder line. Often requested alongside complaints of shoulder tightness.

Onset, Duration and Why It Wears Off

Effect is not immediate. Expression areas typically begin to change within 2–5 days, with the full effect at about two weeks. Muscle-reduction areas such as the masseter change more slowly, over several weeks to a couple of months, because visible slimming follows loss of bulk rather than loss of movement.

Duration is commonly in the range of 3–6 months and varies with dose, area, muscle strength and individual metabolism. It wears off because nerve signalling recovers — this is expected, not a failure of the treatment. Anyone promising permanence is describing something other than botulinum toxin.

Risks & Considerations

• Bruising, swelling or tenderness at injection points
• Headache in the days after treatment, particularly with upper-face injection
• Asymmetry, or an unintended change in expression, if dose or placement is not matched to anatomy
• Eyelid or brow droop — uncommon, temporary, resolving as effect wears off
• Masseter treatment: temporary chewing fatigue; excessive or repeated high-dose treatment may hollow the cheek
• Salivary gland: temporary dry mouth or altered swallowing
• Trapezius: temporary shoulder weakness if over-dosed
• Rarely, allergic reaction; effect spreading beyond the intended muscle

Not appropriate during pregnancy or breastfeeding, or with certain neuromuscular conditions. Disclose all medical history at consultation.

Frequently Asked Questions

Q. How long until I see the jaw slim down?

Masseter reduction is gradual. Movement changes within days, but visible narrowing follows the reduction in muscle bulk over several weeks to about two months.

Q. Will my face look frozen?

That is a dosing and placement outcome, not an inherent property. Conservative dosing preserves expression; the aim is a softer line, not an immobile face. If you have had an over-treated result before, say so — it changes the plan.

Q. Does skin botox affect my expressions?

It is placed deliberately superficially, targeting pores and oil rather than the muscles of expression, so significant change in movement is not the intention.

Q. Do I build resistance with repeated treatment?

Antibody formation is possible but uncommon at aesthetic doses. Unnecessarily frequent or high-dose treatment is the main avoidable risk factor, which is one reason we do not shorten intervals on request.

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