Wrinkle reducers are all based on a toxin created by Clostridium botulinum bacteria. In small, controlled doses, injecting a diluted solution of the toxin into a muscle blocks nerve messages, causing the muscle to weaken and relax. Any wrinkles caused by the movement of the muscle will soften, sometimes disappearing altogether. The wrinkle softening effects of wrinkle reducers normally take a few days to kick in, and normally last up to four months. If the same muscle is repeatedly injected, the results tend to last longer, as the muscle is "trained" to relax.
Wrinkle reducers are applied through a thin needle. Several injections are made in each area treated. A topically applied botulism toxin gel, manufactured by Revance, is slated for introduction to the market in 2011.
The most commonly used brands of wrinkle reducers are Botox and Dysport. There are a few studies that indicate that Dypsort may be slightly faster-acting and longer-lasting than Botox.