Botulinum toxin: effect, areas, and limits

Mode of action

Botulinum toxin selectively reduces the activity of chosen muscles and therefore only affects dynamic, expression-related wrinkles - not wrinkles caused by volume loss or skin laxity. For those causes, other procedures such as hyaluronic fillers or tightening treatments are more suitable.

Typical areas and individual planning

Commonly treated areas include, among others, the glabella, forehead, and periorbital region. Selection, dosage, and injection points are always based on the individual's anatomy, muscle strength, and expression; the goal is to preserve a natural expression, not to maximally reduce facial movement.

Onset and duration of effect

Onset typically becomes visible after a few days, with full effect after about two weeks. Duration usually lasts several months and varies individually; a fixed timeframe cannot be guaranteed.

Extended use for bruxism

For bruxism or painful masticatory muscle overactivity, the current German S3 clinical guideline on bruxism (AWMF registration number 083-027) lists botulinum toxin injection into the masticatory muscles as a possible treatment option - with a positive but cautious recommendation grade and overall low evidence quality. Studies mainly show a reduction in pain, muscle activity, and bite force; reliable evidence that this permanently prevents all bruxism episodes is lacking. For this indication, use is off-label and requires medical diagnosis and individual counselling. More on this in the article on TMJ disorders, bruxism, and occlusal splints.

Safety, limits, and alternatives

As with other injections, temporary reactions at the injection site and rare, product-specific risks are possible. Contraindications such as pregnancy, breastfeeding, or certain neuromuscular conditions are checked medically beforehand. For volume loss or skin laxity, botulinum toxin is not the suitable treatment - this is where the distinction from hyaluronic fillers applies.

Related topics

• Botulinum toxin or hyaluronic acid?
• TMD, bruxism, and occlusal splints