Botulinum Toxin Type A (Botox Cosmetic) is used to temporarily improve the appearance of moderate to severe frown lines between the eyebrows, called glabellar lines. Botox has been used medically for over a decade. Botox is also used for the treatment of two eye muscle disorders, blepharospasm and strabismus. Botulinum Toxin Type A as well as a different form of Botox - Botulinum Toxin Type B (Myobloc®) is approved for for treatment of cervical dystonia, a neurological movement disorder causing severe neck and shoulder contractions.

How It Works

Botulinum toxins are a group of proteins produced by the bacteria Clostridium botulinum. While food contaminated with Clostridium botulinum can cause botulism, botulinum toxins can be turned into a safe and effective treatment for wrinkles and muscle spasms. The protein is a neurotoxin that causes the potentially fatal food-related paralysis called botulism. However, when administered in a medical setting, an injectable, sterile, purified botulinum toxin is used. Small doses of the toxin are injected into the affected muscles and block the release of the chemical acetylcholine, which would, in normal circumstances, signal the muscle to contract. The toxin paralyzes or weakens the injected muscle, inhibiting the contraction. Used properly, this highly toxic substance is remarkably safe and effective for a variety of indications. The dose of Botulinum Toxin A used to treat wrinkles is much smaller that the doses of Botulinum Toxin A or B used for dystonia. Even the dose of botulinum toxin type A or B used for cervical dystonia is typically far less than that which causes botulism.

The Evidence

In placebo-controlled clinical trials involving 405 volunteers (mostly women under 50), Botox was tested on glabellar "frown" lines. After 30 days, the majority of people who had Botox injections rated their glabellar lines as improved or nonexistent. Very few patients in the placebo group saw similar improvement. Investigators found that the severity of the glabellar lines was reduced somewhat for up to 120 days. The treatment, of course, was not permanent, and repeated injections were required to maintain satisfactory results.

Precautions

Botox should be injected no more frequently than once every three months. In addition, the lowest effective dose should be used. During clinical trials, common side effects reported were:

  • Headache
  • Respiratory infection
  • Flu-like syndrome
  • Blepharoptosis (droopy eyelids)
  • Nausea

Less common side effects were:

  • Pain in the face
  • Redness at the injection site
  • Muscle weakness

These side effects were temporary but could last several months.