Botulinum Toxin: Complete Clinical Guide

Botox is not a beauty product. It is a medical tool with a specific mechanism of action, precise clinical indications and absolute contraindications. Who injects it and how they inject it determines 90% of the result.

What is botulinum toxin

Botulinum toxin type A is a purified protein produced by the bacterium Clostridium botulinum. In tiny therapeutic doses and under controlled application, it reversibly blocks the nerve signal that commands muscle contraction. Without contraction, the skin over the muscle relaxes and dynamic wrinkles stop forming.

In Portugal, the botulinum toxin type A formulations approved by INFARMED for aesthetic use are three: Botox® (Allergan), Azzalure® (Galderma) and Bocouture® (Merz). All three products share the same mechanism of action. The differences between them lie in protein complexation and speed of onset, not in efficacy. The final result depends on medical technique, not on brand.

Botulinum toxin does not erase wrinkles. It relaxes the muscle that creates them. It is a preventive treatment targeting the source of the problem, not a surface corrector.

How it works in the muscle

The toxin binds to pre-synaptic nerve terminals and blocks the release of acetylcholine, the neurotransmitter that triggers muscle contraction. The effect is localised, dose-dependent and reversible, because over 3-4 months the body regenerates the blocked nerve terminals.

What this means in practice:

• The skin over the treated muscle stops folding repeatedly, which softens existing wrinkles and prevents new ones from deepening.
• The muscle does not atrophy permanently — it simply rests. Function recovers fully once the effect wears off.
• Dose is measured in units. Each muscle has a reference dose; the final dosage is individualised based on the thickness and tone of each patient's muscle.
• Overdosing produces a "frozen face" effect. Underdosing fails to treat effectively. Calibration is the doctor's work.

Treatment areas at Cosmo Clinic

Botulinum toxin treats dynamic wrinkles: those caused by muscle movement. Deep static wrinkles, visible even at rest, require hyaluronic acid filler. We frequently combine both in a single session.

Facial areas:

• Forehead — horizontal lines from the frontalis muscle. Careful dosing to avoid brow drop.
• Glabella ("11" lines) — the most treated area globally. Two to five injection points.
• Crow's feet — lateral lines from the orbicularis oculi when smiling.
• Bunny lines — diagonal lines on the sides of the nose.
• Nose tip lift — relaxes the depressor septi nasi muscle.
• Gummy smile — reduces upper gum exposure when smiling.
• Chin — smooths irregular texture ("orange peel") and mentalis protrusion.
• Lip flip — slightly everts the upper lip outward without filler.
• Platysmal bands — softens vertical neck cords (Nefertiti technique).

Functional area:

• Hyperhidrosis — excessive axillary, palmar or plantar sweating. Medical treatment with results lasting 6-9 months.

Recovery: what happens day by day

The post-treatment period has specific rules. Following these instructions is decisive for the final result and for preventing toxin migration to adjacent muscles.

Results timeline:

• Days 3-7 — first visible effects, muscle begins to relax.
• Day 14 — full result. Toxin has reached maximum action.
• Months 3-4 — gradual return of muscle motility begins.
• Months 4-5 (with regular treatments) — interval between sessions tends to lengthen.

A small bruise may appear at the injection point. It resolves in 5-10 days. This is not a complication — it is a consequence of local vascularisation.

Who it's for. Who it's not for.

Botulinum toxin is not a universal solution. Being honest about indications and contraindications is part of the Cosmo Clinic protocol.

Main indications:

• Active dynamic wrinkles (appear with facial expression).
• Dynamic wrinkles that remain visible at rest (preventive phase).
• Prevention of wrinkle deepening from age 25-30 onwards.
• Axillary, palmar or plantar hyperhidrosis.
• Gummy smile, bruxism, muscle asymmetries.

When Botox is not the answer:

• Deep static wrinkles visible at rest — these require filler, not toxin.
• Facial volume loss (deep nasolabial folds, loss of cheekbone definition) — indication for hyaluronic acid filler.
• Skin laxity — the toxin relaxes muscle, it does not treat loose skin.
• Expectation of a permanent result — the effect is temporary by definition.

Botox vs Filler: when to use each

The most common source of confusion. In brief:

The two treatments complement each other. The most common combination at Cosmo Clinic is toxin on the glabella and forehead plus filler on the nasolabial folds or lips — in a single session.

Frequently asked questions