New research has found that Botox, a toxin that paralyzes facial muscles to reduce lines, can ironically cause more wrinkles.
Published in the Journal of Cosmetic Dermatology on May 11, the study suggests that in order to compensate for the paralyzed muscles when trying to recreate facial expressions, other muscle groups come into play, causing lines in un-treated places.
One of these side effects are the well-known 'bunny lines' across the nose, seen on stars such as Kylie Minogue.
Dr David Becker, assistant professor of dermatology at Weill Cornell Medical College in New York and quoted in the study, already warned of unwanted effects of Botox seven years ago when he told the BBC: "(In the case of Botox being injected between the eyebrows), following treatment, muscles in the upper nose, middle eyebrow and eyelid may try to recreate the expression of a scowl. Repetitions of this action cause new wrinkles."
Becker also stressed, however, that in general, the treatment was largely regarded as safe and effective and that any new lines would be less prominent than the ones treated in the first place. According to some medical sites, 'bunny lines' can be prevented by injecting small amounts of Botox into the nose.