Why it's done
By Mayo Clinic staffBotox injections block certain chemical signals from nerves, mostly signals that cause muscles to contract. This results in targeted muscle paralysis, which can have therapeutic or cosmetic effects, especially where muscles are chronically tight or spastic.
Botox
The Food and Drug Administration (FDA) has approved Botox to treat the following medical conditions:
- Neck pain and abnormal head position associated with severe muscle spasms of the neck (cervical dystonia)
- Lazy eye (strabismus)
- Twitching of the eyelids (blepharospasm)
- Muscle stiffness in elbow, wrist and finger muscles due to increased muscle tightness in the upper arms (upper limb spasticity)
- Excessive underarm sweating (hyperhidrosis), where the Botox weakens the action of the sweat glands rather than muscles
- Chronic migraine — a condition that causes headaches on more than 14 days a month, including a migraine on at least eight of those days
Doctors sometimes use Botox to treat other conditions, such as back pain, bladder dysfunction, pelvic floor problems and others. But more evidence of Botox's effectiveness for these conditions is needed before it can be considered standard therapy.
Botox Cosmetic
Botox Cosmetic can temporarily relax the facial muscles that underlie and cause wrinkles, making them less noticeable. The FDA has approved Botox as a temporary treatment for moderate to severe frown lines between the eyebrows. However, Botox can be used to treat other facial wrinkles as well, such as the lines that fan out from the corners of the eyes (crow's-feet) and the forehead furrow.
Botox won't reverse wrinkling caused by sun damage. Also, it's less desirable to treat the lines around your mouth because muscles in this area are needed for eating and talking. Your skin type, skin thickness and degree of wrinkling all play a role in determining whether these injections are effective for you.
- Botox medication guide. Food and Drug Administration. www.fda.gov/downloads/Drugs/DrugSafety/UCM176360.pdf. Accessed May 3, 2010.
- OnabotulinumtoxinA: Drugdex evaluations. Micromedex Healthcare Series 2.0. http://www.micromedex.com. Accessed May 3, 2010.
- Botox (medical). The Foundation of the American Academy of Ophthalmology. http://www.eyecareamerica.org/eyecare/treatment/botox/. Accessed May 2, 2010.
- Carruthers J, et al. Consensus recommendations on the use of botulinum toxin type A in facial aesthetics. Plastic Reconstructive Surgery. 2004;114(suppl.):1S.
- Flynn TC. Update on botulinum toxin. Seminars in Cutaneous Medicine and Surgery. 2006;25:115.
- Botulinum toxin. American Academy of Dermatology. http://www.aad.org/public/publications/pamphlets/cosmetic_botulinum.html. Accessed May 2, 2010.
- FDA approves Botox to treat chronic migraine. Food and Drug Administration. http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/ucm229782.htm. Accessed Oct. 23, 2010.

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