Potential Side Effects of Botox

BOTOX ® is the shortened name given to botulinum toxin, a protein that is most commonly used in cosmetic dermatology to treat brow lines (glabellar lines), facial creases and wrinkles.? It is also used to treat a variety of other medical conditions including Cerebral Palsy, Torticollis, some forms of incontinence and excessive perspiration.? Although side effects of BOTOX ® do exist, they are not often serious and can be easily treated.


Bruising at the site of the injection is perhaps the most common and the least dangerous of the potential side effects.? Although it may initially appear unsightly, the bruising will usually disappear within a matter of days.

Flu-Like Symptoms?

BOTOX ® is a bacterial toxin, and it is antigenic. When injected, it elicits a response from the body not related to the desire action. This response is due to its immunogenicity. Generalised reactions to the entry of the antigen can give rise to flu-like symptoms such as mild fever, headaches, muscle aching and fatigue.

Facial Side Effects

When injected to smooth out facial creases and wrinkles, particularly brow lines, BOTOX ® may temporarily some of the muscles that elevate the eyelids leading to drooping of the eyelids (also called blepharoptosis). In rare instances, if the BOTOX ® affects the muscles that move the eyeballs, then temporary loss of peripheral or central vision may occur. This is dependent on whether the muscles that move the eyeball towards or away from the middle of the face are affected.


Blocking of the phrenic nerve (a nerve found in the neck) when BOTOX ® is injected into spastic neck muscles may lead to temporary paralysis of the diaphragm. This can cause breathing difficulties and breathless. If this diaphragm is affected only patchily, then although it could still function, movement of air in and out of the lungs may be inefficient and incomplete predisposing to chest or respiratory infections.

Abdominal Side Effects

Inadvertent injection of Botox into bowel walls can occur when BOTOX ® is injected via a camera system into the bladder wall.? Injection into bowel walls may result in temporary paralysis of segments of the bowel, which in turn can lead to the slowing down of the movement of fluid and digesting food along the intestinal tract.? The affected individual may feel bloated because bowel gas is not moved down and may also suffer from nausea, vomiting and constipation.

Side Effects on the Bladder

One of the most predictable side effects of the administration of BOTOX ® is when it is used in the bladder. It is administered via a cystoscope into the bladder muscle and just below the internal lining of the bladder. At these two sites, BOTOX ® reduces the ability of the bladder to contract and reduces its sensitivity respectively. These two actions are necessary to treat incontinence of the urge type.?

The occurrence of unwanted paralysis of the bladder when used in this method varies between 1 in 20 to 1 in 5 patients depending on the dosage. Patients who are affected by this side effect are unable to void at all or at best are unable to empty their bladders completely. When BOTOX ® is used to treat the bladder, patients must be warned that some of them may expect to have to use a catheter to help emptying of the bladder.

Side effects of BOTOX ® typically last a maximum of six months as the treatment is temporary and potential patients should always consult a doctor before undergoing treatment.

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