How does Botulinum Toxin Work?

With so many options and so many different recommendations from different surgeons, it is no wonder patients are confused as to how to proceed when discussing facial rejuvenation with their plastic surgeon.

So many options for facial rejuvenation

You could go to 10 different specialists and obtain 10 different recommendations. These can range from a 15 minute filler and Neuromodulator procedure, to a 6 hour surgical procedure under general anesthesia.

In this and ensuing posts, we will discuss the most common and safe options for women interested in facial rejuvenation

Botulinum Toxin

Although the proprietary name for one form of neuromodulator, Botulinum Toxin has become the way most people refer to the injectable used to limit facial rhytids or wrinkles, specially in the forehead and periocular region.

There are multiple varieties of modulators. The difference in these are cost and dosing concentrations. Efficacy among these different brands has not been elucidated; however, practitioners have reported high patient satisfaction with all three.

How it Works

Botulinum toxin prevents the vesicles filled with Acetylcholine from opening into the synapse and releasing Acetylcholine, thereby limiting muscle activity

Dilute botulinum toxin is injected into facial muscles and affects the motor end plate of the motor nerves innervating the respective muscles. This results in a weakening or paralysis of these muscles that is exhibited as a relaxation of the muscle and therefore a loss of wrinkles in the overlying skin. Wrinkles that form from underlying muscle tension are ideal for treatment. These include the forehead lines, lines between the eyebrows, and lines on the lateral corner of the eyes.

Indications and Contraindications

Patients that are good candidates have forehead, glabella (region between the eyebrows) and temple lines and wrinkles they would like to be improved.

In addition, when placed in selective areas can result in eyebrow elevation, and this has resulted in less interest in surgical brow lift techniques since a simple injection can result in adequate brow lifting.

Newer techniques include placement of small amounts around the mouth to raise or lower the lips or eliminate wrinkles.

Patients should not be on blood thinners that can result in bruising and should not suffer any conditions that result in neuromuscular weakness like Myasthenia gravis. Finally, the should not be pregnant or breastfeeding or have an allergy to the ingredients


The first step in planning a treatment involves asking the patient to raise their eyebrows, frown, smile and wrinkle their nose. These maneuvers exhibit the most common lines and wrinkles that botulinum toxin can treat.

The medication comes in a small vial with either 50 or 100 units of the toxin inside. It is diluted with normal saline to make a concentration of 2 to 2.5 units per 0.1 cc. One 1 cc syringe can be used to administer 25 units which is an appropriate starting dose for someone’s first treatment

The treatment starts with a cleansing of the involved skin with an alcohol wipe. Sometimes a topical anesthetic cream is used in patients that are sensitive. Using a very small needle the solution is injected into the forehead, glabella and crow’s feet muscles, sometimes superficially and sometimes deep depending on the muscle locations. Small amounts are injected throughout, consisting of multiple small injections.

Care is taken to not inject excessive amounts in certain areas as this can result in eyebrow ptosis or descent, and even paralysis of the levator muscle of the upper eyelid.

Following the injection, a cold pack is placed throughout the affected area for a few minutes to limit bruising afterwards. By carefully avoiding any superficial veins, this complication can be eliminated.


The results are no immediately visible. Over the next 2-5 days, you will notice the effects. Lines and wrinkles across your forehead, glabella and crow’s feet will slowly fade and sometimes completely be eliminated.

In rare cases, some asymmetry may occur if a muscle is more active on one side than another. Sometimes an additional treatment is needed a week after the original injection to address any asymmetries that arise.

The results should last for 3-4 months. At that time a new treatment can be scheduled to keep the effect going.

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