The Substance is a 2024 body horror film written and directed by Coralie Fargeat. It follows a fading celebrity, Elisabeth Sparkle (Demi Moore), who, after being fired by her producer (Dennis Quaid) due to her age, uses a black market drug that creates a younger version of herself (Margaret Qualley) with unexpected side effects. The film is noted for its satirical elements and grotesque, hyperrealistic imagery.

The Substance is Fargeat's second feature film, after Revenge (2017). Motivated by societal pressures on women's bodies and aging, she wrote the screenplay in two years, assembling a production team spanning France, the United Kingdom, and the United States. Principal photography in France lasted 108 days. It extensively used prosthetic makeup and other practical effects, including suits, puppetry, dummies, insert shots, and approximately 21,000 liters (5,500 US gallons) of fake blood to portray Elisabeth's drug-induced transformation. The film score was written by Raffertie and features a cover of "Pump It Up!" by DJ Endor.

The Substance premiered on May 19, 2024, at the 77th Cannes Film Festival main competition, where Fargeat won Best Screenplay. Originally set to be distributed theatrically by Universal Pictures, it was released theatrically in the United Kingdom and the United States by Mubi on September 20, 2024, and in France by Metropolitan Filmexport on November 6, 2024. It is Mubi's highest-grossing film, grossing $77–82 million at the box office against an $18 million production budget. It received positive reviews and won Best Makeup and Hairstyling at the 97th Academy Awards, along with numerous other accolades. Moore's performance won her a Golden Globe Award, Critics' Choice Award, and Screen Actors Guild Award, and a nomination for the Academy Award for Best Actress.