Botox is a drug that is best known for its role in smoothing wrinkles in aging faces. It is made from the botulinum toxin and works by paralyzing muscles for a few months to a year. The drug can also be used to treat recalcitrant migraines and headaches, as well as uncontrollable blinking, neck spasms and overactive sweat glands.
Made by the company Allergan, Botox is derived from the potent neurotoxin made by the bacteria Clostridium botulinum. The same bacteria can cause the deadly type of food poisoning known as botulism.
Botox usually works best on facial wrinkles that form dynamically, such as frown or smile lines that disappear when the face is at rest.
But because Botox temporarily paralyzes muscles, the compound is also used for many types of spasmic muscle pain. Studies suggest the medication is effective at reducing neck spasms, rapid blinking, and can help people who have overactive bladders, which cause the feeling of "always needing to go."
The injection is also approved for use to reduce migraine pain by the Food and Drug Administration, though it's mainly recommended for people with more than 14 migraines a month. However, a 2012 review study in the Journal of the American Medical Association found that Botox could eliminate two to three migraines a month, but wasn't much good at all in relieving pain from tension headaches.
Some doctors also use Botox to eliminate excessive sweating from the underarms, palms or feet, by blocking the signals sent by nerves to the sweat glands.
All of these treatments eventually wear off and need to be done every three to six months.
Though Botox is generally considered safe, it often causes pain, swelling and bruising right after an injection. If the injection is placed improperly, the medicine can migrate to other locations in the face and cause crooked facial expressions, including a lopsided smile or droopy eyelids or dry tear ducts.
Very rarely, the drug can cause life-threatening side effects, including allergic reactions. The bacterium can also sometimes travel to other parts of the body, where it can cause muscle weakness, vision problems or trouble swallowing and breathing.
People who have Botox injections may also have trouble making the full range of facial expressions. In his book, "The Face of Emotion: How Botox Affects Our Moods and Relationships," (Palgrave MacMillan, 2013), Eric Finzi argues that people's feeling of an emotion, such as anger, sadness or happiness, may be triggered by the facial expression associated with it. As a result, Botox may dampen people's abilities to feel emotion by constraining their facial expressions. That could be a good thing when it comes to depression: A 2012 study in the Journal of Psychiatric Research found that people suffering from major depression who received a Botox injection to the frown lines showed a dramatic improvement in their symptoms.