N-methyl-3-methoxytyramine + S-adenosyl-L-methionine <=> N,N-dimethyl-3-methoxytyramine + S-adenosyl-L-homocysteine + H(+)
n-methyl-3-methoxytyramine + s-adenosyl-l-methionine <=> n,n-dimethyl-3-methoxytyramine + s-adenosyl-l-homocysteine + h(+)