Botox is the commercial name for botulinum toxin A, a neurotoxin that temporarily removes wrinkles by paralyzing the muscles that cause expression lines.
Use of Botox has exploded in the last five years, after a Canadian ophthalmologist discovered that botulinum toxin appeared to smooth the expressions of patients who received the therapy for muscle spasms.
Almost all of the studies on Botox to date have looked at female patients, who make up the overwhelming majority of Botox consumers. However, a new study by Drs. Jean and Alastair Carruthers of the University of British Columbia reveals how men and women respond differently to a range of Botox doses.
The researchers compared the self-reported satisfaction with results of male and female patients who received one of four different doses of Botox.
Each received one treatment of either 20 units, 40 units, 60 units or 80 units of Botox -- the outer edge of what's thought to be a safe dose.
After 52 weeks, men who received only 20 units of treatment showed no improvement, but those who were treated with 40 to 80 units showed optimum results. Women, on the other hand, showed greater results at much lower doses.
"Men do respond to Botox, but to achieve results they need a dose that's at least twice as high as females," says Alastair Carruthers.
The authors found no additional side effects or complications associated with the higher doses.
Before this study, doctors have had to rely on guesswork to guide treatment dosage for male patients.
"I play with the dose and usually start with a little because you can always do more," says Dr. Jack Resneck, a private practice physician from Shreveport, La.
Men currently represent 15 percent of Botox users, but their legions are growing, the researchers say.
"Some of the stereotypes we have had about male attitudes towards cosmetic procedures are not born out by our evidence," Carruthers says. Men are just as interested in appearing youthful despite the prevailing notion that men with wrinkles are sometimes considered more masculine and distinguished, he says.
"Men are becoming a new cosmetic market and this is just part of it," says Brian Stamper, 30, a San Francisco resident who says he's considering the treatment.
Resnick believes Botox is a more appealing alternative to invasive cosmetic surgery for men because they don't have to miss work: Botox therapy requires almost no recovery time.
The study was presented recently at the American Academy of Dermatology's annual meeting in San Francisco and was funded by Allergan, the pharmaceutical company that manufactures Botox.