HEARTS SOLD SEPARATELY will serve as Mariah the Scientist's fourth studio album, proceeding her October 2023 album To Be Eaten Alive. This album was first teased on March 31, 2025. when an interviewer asked: "What are you working on this year?" Mariah replied, "It’s been taking so many nights to put together, but it’s done" On April 24, 2025, Mariah appeared as a guest on Summer Walker’s podcast series, Over It Radio. She reveals the concept behind her upcoming album using a “little green toy soldier.” This toy soldier symbolizes a dedication to a cause such that an individual would be willing to die for. The “toy” aspect also represents a feeling of being “small and not taken seriously.” Mariah uses this as a metaphor for how men often disregard women’s effort. On May 2, 2025, Mariah released her lead single off the album, " Burning Blue" along with a music video for the track. After keeping quiet on the album’s information for some time, on July 8, 2025, Mariah announced through Instagram the official cover and track list for the album & that the album would see an official release on August 22, 2025. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.