11/09/2026
If you’ve ever looked at the warning on a Diet Coke and thought, “Wait… is this dangerous?” — let’s clear that up. 🥤
The ingredient people often worry about is phenylalanine. Phenylalanine is an amino acid — one of the building blocks of protein — and you naturally get it from high-protein foods such as eggs, chicken and meat.
So seeing “contains a source of phenylalanine” on a can doesn’t mean the drink is dangerous for the average person. That warning is there specifically because of a rare inherited condition called phenylketonuria (PKU), where the body can’t properly process phenylalanine. For someone with PKU, keeping phenylalanine intake under control is important.
For everyone else, having a Diet Coke isn’t something you need to panic about. In fact, the amount of phenylalanine in one Diet Coke is small compared with the amount you’d get from a normal serving of protein-rich food.
So next time you fancy a Diet Coke, have one. One drink isn’t going to be the end of the world. 😌
Good day. 🥤