Aspartame, when it hits your intestines, immediately decomposes into 40% phenylalanine, 40% aspartic acid, and 20% methanol. Phenylalanine and aspartic acid are nutritious amino acids, otherwise known as protein. Since aspartame is so much sweeter than sugar, it’s used in quantities small enough to make the methanol intake levels lower than what you would get from a cup of fruit juice.

There’s no real danger.