The liquid used for the "re-agent," as in the first film, was taken from glowsticks.
One of the original plots for the film involved Dan Cain being recruited to Washington, DC to bring the deceased President of the United States back to life with the help of Herbert West. This was later carried over to the unmade House of Re-Animator.
At one point Dr. West suggests that the noises coming from his laboratory wall are just "probably rats in the wall." This is a reference to one of H.P. Lovecraft's better known stories "Rats In The Wall."
Barbara Crampton, star of the first Re-Animator (1985) turned down the role of the Bride on advice from her agent who convinced her that it was beneath her to have such a small role. Kathleen Kinmont was cast instead. She and Crampton had worked together in a nude scene in Fraternity Vacation (1985).
Kathleen Kinmont had to have 15 different body casts made for her monster makeup and costume. During the application of a full-body cast, male make up effects artists covered her nude body in liquid latex. At first it was cold, but it started to heat up as it hardened. It soon became so hot she fainted. When she woke up, she was sitting on a chair in a robe. She asked how she got there, and the guys told her they removed the latex once it hardened, dressed her in the robe, and set her in the chair. She was more concerned she'd have to do the miserable casting process again than she was about several guys handling her naked body as they dressed her. Luckily, they said the cast looked great so they didn't need to do it again.