N-methylmescaline + S-adenosyl-L-methionine = N,N-dimethylmescaline + S-adenosyl-L-homocysteine + H(+)
n-methylmescaline + s-adenosyl-l-methionine = n,n-dimethylmescaline + s-adenosyl-l-homocysteine + h(+)