Does taking nutritional supplements (such as slow-release protein, which takes 8 hours to be absorbed) in Ramadan, several hours before Fajr, break the fast?

Consuming protein before dawn does not break the fast, as long as the accountable individual does not transgress the boundaries set by Allah by consuming anything forbidden after the true dawn appears. This is based on the Almighty's saying: "And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset."