Beginning on September 22, 2020, Blackpink's label YG Entertainment uploaded various teasers for The Album from each member on their respective social media accounts.

[6] "Lovesick Girls" was made available in conjunction with The Album on October 2, 2020, serving as the record's third single following "How You Like That" and "Ice Cream" (with Selena Gomez), which were released in June and August, respectively.

[14] Musically, "Lovesick Girls" is a dance-pop and electropop number containing influences from EDM and punk rock,[15][16] incorporating acoustic guitar instrumentations.

[17] Kat Moon from Time wrote that Blackpink's voices "are layered over acoustic guitar to create a breezy and mellow ambience", contrasting its production to "the hard-hitting nature" of the group's 2018 and 2019 singles.

[18] Douglas Greenwood from British Vogue highlighted the song's "dreamy electronica" production, and wrote that its soundscape felt "liberating" and "club-friendly".

[19] The lyrical content of "Lovesick Girls" explores owning independence through heartbreak,[20] with Jason Pham from StyleCaster describing the track as a "heartfelt anthem about longing for love, despite knowing how much it hurts".

Ranking it the second best track of the album, Billboard's Jason Lipshutz opined that the song demonstrated the ambition of Blackpink "as they tackle well-worn subject matter with a fresh aesthetic".

[24] Callie Ahlgrim from Insider called "Lovesick Girls" an "EDM-flavored sequel" to Ariana Grande's 2019 single "7 Rings",[25] while Tim Chan from Rolling Stone wrote how it "turns a familiar lament about being alone into an anthemic dance track that’s just begging for a lightstick and clubs to reopen".

[26] Hannah Zwick from Consequence of Sound praised the group's vocals and regarded "Lovesick Girls" as the highlight track from The Album.

[27] Moon from Time agreed, lauding "Lovesick Girls" as the "true gem" of the record and commended its blend of Blackpink's characteristic "heavy electronic production" with a more "stripped back" musical arrangement.

[18] Raul Stanciu from Sputnikmusic wrote that the song "is probably the closest Blackpink have steered towards the lovely disco grooves of 'As If It's Your Last'" in 2017, which he deemed as one of the group's best singles.

[28] Jo Ji-hyeon of IZM ranked "Lovesick Girls" amongst the best records released in South Korea during 2020, writing that it aptly blends the vibrant charm of 2000s American teen pop with Blackpink's distinctive style.

She felt that the song's synthesizer riffs and tightly woven electronic sound, which embodied the essence of K-pop, generated a source of "thrilling pleasure".

[29] Taylor Glasby from Dazed ranked it the 14th best K-pop song of 2020, praising its composition and highlighting how Jisoo and Rosé's "vocal rawness" brought depth to its production.

[30] Don Jaucian from CNN Philippines felt that although the group may have had released similar singles before, they had never "bared their souls like in 'Lovesick Girls'", and remarked that it is "sure to become the powerful anthem that it is in many years to come".

[73] The video employs fashion to express emotions, integrating darker attire to symbolize pain and loss, while juxtaposing it with brighter outfits that convey a sense of hope.

[75] Following the release of the music video, however, the Korean Health and Medical Workers Union raised concerns about member Jennie's nurse outfit which was featured in her solo scene.

The union released a statement stating that YG Entertainment "sexually objectified the image of a nurse" in the video, and that "the costume perpetuated hyper-sexualized stereotypes about the profession".

[82] It was also performed during the group's headlining sets at Coachella in California, where rainbow streamers were shot into the sky, and BST Hyde Park in London in 2023.