Botox is the trade name for botulinum toxin type A, one of several different toxins produced by Clostridium bacteria. It’s also one of the safest drugs that we use. For wrinkles, usually 10-20 units per site are injected (to a maximum 40 units). It would take three to four thousand units to make a person sick.
When injected, it temporarily paralyzes the muscles, underlying wrinkles such as frown lines and crow’s feet smoothing out the skin on top. (Please note that if this is your first injection, it may take up to several treatments before lines soften.) Even though one may have no muscle movement, there can still be lines present simply due to the fact that the skin has a memory of being creased and will take time to soften as the muscle continues to lay flat underneath.
Botox inhibits the nerve terminal so that the muscle will not respond. One literally cannot frown after the treatment, but sensation is not lost. The nerve is still there, and the end of the nerve eventually sprouts a new terminal.
How Long Does It Last?
Anywhere from three to six months. In low doses, the treatment can be continued indefinitely.
There's More To It
There is the chance of other muscles becoming involved. Eyelid drooping can occur if the Botox seeps below the eyebrow and hits the muscle that controls the lid, but that is very rare; and it’s probably related to the injection technique, the placement, or rate of injection. Eye drops can reverse the Botox effect for about six hours. Otherwise the patient must wait until the nerve regenerates.
It has been approved by the FDA for treating such conditions as crossed eyes and uncontrollable eye movements. Since then, it has been used for some 15-20 different conditions including wrinkles. The FDA can approve a drug, but it’s up to the physicians to decide how to use it and for what purpose.