At the end of the music video of Twice's first English single, " The Feels", a full-length album scheduled to be released in November 2021 was teased. The physical album comes in five versions: Study About Love, Break It, Explosion, Full of Love and Result File. um museum in South Korea, which uses experiential and interactive technology like VR, AR, AI and 5G. The track “Candy” was performed on TWICE’s 6th Anniversary celebration H6ME PARTY with 6NCE, on October 29, 2021, before its official release. The 16-track project, their longest to date, is led by the single “The Feels,” their first full English digital single, which was released on October 1, 2021.

Raj compared it to Twice's song "Scandal" ( Taste of Love), for having "the same calculated and dangerous allure". It is a 150-pages photobook, with behind-the-scenes pictures taken during the album photoshoot and the "Scientist" music video shooting.

It debuted at number three on the Billboard 200 with 66,000 album-equivalent units, becoming the group's fourth and highest entry on the chart.

It consists of sixteen tracks, including the group's first English single " The Feels" and lead single " Scientist".The song's lyrics are about playful pushing and pulling in a relationship "to bring the other person closer". AllMusic's David Crone concluded his review by saying the album is Twice's best release to date and that it "surpasses expectations, infusing the group's love-centric lyricism with newfound confidence and creative flair. The letters O and T represent the initials of Once—the group's official fandom's name—and Twice, respectively, while the heart symbol ( <3) represents love; thus, the "formula of love" can be verbalized as "Once plus Twice equals love". Another English song, "Icon", is a "hard-hitting" and "sensual" [12] synth-pop track with elements of reggae-pop. Formula of Love marks the first time ever that TWICE released songs in which not all 9 members participate.