A method of: a. administering botulinum toxin to achieve an extended duration cosmetic effect in an individual, the method comprising: administering by injection a first effective amount of a sterile injectable composition into an area of the individual in need of treatment to achieve the cosmetic effect following a first treatment with the composition; wherein the first effective amount of the composition administered by injection to the individual achieves the extended duration cosmetic effect having at least about a 6 month to about a 10 month duration of effect, optionally, before a second or subsequent effective amount is administered; or b. reducing wrinkles, lines, or furrows in an individual in need thereof, the method comprising: administering to the individual as a single dose injection a composition; wherein the single dose injection of the composition provides a single treatment having at least about a six month to about a 10 month duration of effect in reducing the wrinkles, lines, or furrows in the individual, thereby extending treatment interval duration for the individual; and wherein the composition of a. or b. comprises a pharmaceutically acceptable diluent suitable for injection; and a botulinum toxin component of serotype A and having a molecular weight of 150 kDa; and a positively charged carrier component comprising the amino acid sequence RKKRRQRRRG- 15 -GRKKRRQRRR; wherein the botulinum toxin component is administered to the individual in an effective amount of 20 U to 60 U; wherein the positively charged carrier is non-covalently associated with the botulinum toxin component. a. administering botulinum toxin to achieve an extended duration cosmetic effect in an individual, the method comprising: administering by injection a first effective amount of a sterile injectable composition into an area of the individual in need of treatment to achieve the cosmetic effect following a first treatment with the composition; wherein the first effective amount of the composition administered by injection to the individual achieves the extended duration cosmetic effect having at least about a 6 month to about a 10 month duration of effect, optionally, before a second or subsequent effective amount is administered; or administering by injection a first effective amount of a sterile injectable composition into an area of the individual in need of treatment to achieve the cosmetic effect following a first treatment with the composition; wherein the first effective amount of the composition administered by injection to the individual achieves the extended duration cosmetic effect having at least about a 6 month to about a 10 month duration of effect, optionally, before a second or subsequent effective amount is administered; or b. reducing wrinkles, lines, or furrows in an individual in need thereof, the method comprising: administering to the individual as a single dose injection a composition; wherein the single dose injection of the composition provides a single treatment having at least about a six month to about a 10 month duration of effect in reducing the wrinkles, lines, or furrows in the individual, thereby extending treatment interval duration for the individual; and wherein the composition of a. or b. comprises a pharmaceutically acceptable diluent suitable for injection; and a botulinum toxin component of serotype A and having a molecular weight of 150 kDa; and a positively charged carrier component comprising the amino acid sequence RKKRRQRRRG- 15 -GRKKRRQRRR; wherein the botulinum toxin component is administered to the individual in an effective amount of 20 U to 60 U; wherein the positively charged carrier is non-covalently associated with the botulinum toxin component. administering to the individual as a single dose injection a composition; wherein the single dose injection of the composition provides a single treatment having at least about a six month to about a 10 month duration of effect in reducing the wrinkles, lines, or furrows in the individual, thereby extending treatment interval duration for the individual; and a botulinum toxin component of serotype A and having a molecular weight of 150 kDa; and a positively charged carrier component comprising the amino acid sequence RKKRRQRRRG- 15 -GRKKRRQRRR; wherein the botulinum toxin component is administered to the individual in an effective amount of 20 U to 60 U; wherein the positively charged carrier is non-covalently associated with the botulinum toxin component.