In the 1950s, scientists discovered that botulinum toxin could reduce muscle spasms. Extensive work in the 1970s and 1980s in the area of the eye and a disease called strabismus (cross eyes) led to the discovery that botulinum toxin can significantly help people with this problem. The Allergan Pharmaceutical Company purchased the rights to this drug in 1989 and named it BOTOX®. The following year, they received FDA approval for the use of Botox for strabismus and blepharospasms. FDA approvals that followed include treatment of cervical dystonia (neck spasms), treatment of frown lines between the brow (called BOTOX Cosmetic®), treatment of severe underarm sweating in 2004, treatment of upper limb spasticity, treatment of urinary incontinence and spasticity, and the treatment of dynamic wrinkles along the sides of the eyelids, also known as crow’s feet (BOTOX Cosmetic®).
The Composition & Biological Activity of Botox
Onobotulinumtoxin A, or BOTOX Cosmetic®, is a highly purified protein derived from the bacteria clostridium botulinum. It is very potent, and therefore, there is very little actual protein in an entire bottle of the medicine. Because so little protein is used to treat these FDA-approved areas, there is little chance for immune response and possible allergic reaction.
When injected into the intended muscle, like the corrugator muscle that makes the furrows between the eyebrows, the protein binds to the nerve endings and gets “swallowed” by the nerve into its interior. Once the Botox protein is inside the nerve, it can then go to work! The Botox protein interferes with an important protein inside the nerve ending designed to allow release of the neurotransmitter acetylcholine. This neurotransmitter is necessary to complete transmission of the nerve signal to the muscle, and therefore causes muscle contraction. This nerve protein is called SNARE, and Botox cuts a piece of the protein off called SNAP 25, which prevents the neurotransmitter for being released.
Because all other biologic activities of the nerve ending are unaffected, eventually the Botox protein is degraded into amino acids to be used for cellular repair, including the SNARE protein complex. In general, 50 to 90 percent of muscular activity returns in three months.
Botox & Skin Wrinkles
Botox can make your skin smoother by relaxing muscles around the eyes, mouth, forehead, and between the eyebrows. Even lines that are present when these muscles are not contracting can improve with time after your first Botox injections. The degree of smoothing is dependent on many factors, including skin thickness, your age and sex, and the amount of environmental injury your skin has sustained in your life (sun damage and cigarette smoke, primarily). Recommended intervals between Botox injections should be between three and four months to achieve the best results.