One day, after being told by Dom’s father that Grace has gone missing, Henry finds her in the koi pool, wearing what was to have been her wedding dress.

After the last issue of the newspaper is released, to which Henry has contributed a heartfelt essay about the biochemistry of teenagers, they meet in a school hallway.

[1] In June 2019, it was announced Lili Reinhart and Austin Abrams had joined the cast of the film, with Richard Tanne directing from a screenplay he wrote.

The site's critics consensus reads, "For better and for worse, Chemical Hearts captures the well-worn ups and downs of melodramatic teenage love - and countless other films about it.

[6] Sheila O'Malley of RogerEbert.com described the film as "sneakily subversive," and "very unpredictable," writing that, "there's much to be said for what Tanne has pulled off in Chemical Hearts, for his gentle and measured approach.

"[7] San Francisco Chronicle's G. Allen Johnson concluded his review by asserting that "what makes Chemical Hearts so good is it’s unafraid of its feelings.

"[9] David Ehrlich, reviewing for IndieWire, praised Tanne's direction of the film, writing that he employed "a more patient and open-ended aesthetic than you’d expect to find in a YA adaptation; shot on a 35mm stock that can make an entire bedroom vibrate with potential, some entire scenes are captured in just a handful of static medium-wide shots that aren’t afraid to set these characters adrift in a vast sea of their own feelings."

"[11] The Columbia Chronicle pointed out that the portrayal of teenage experiences sometimes felt forced, with a focus on the male protagonist's narrative overshadowing the female lead's depth.

[12] Empire Online called it "an impassioned and imperfect portrait of teenage grief and heartbreak," with a "script that seems designed to be repurposed in retweets, Instagram stories, and probably even tattoos.

[14][15] Youth-oriented online media platform The Second Angle placed the film at number 5 on its list of "Ultimate 25 movies every girl must watch before turning 25.

"[16] Comic Book Resources listed the film as #3 in their article, "10 Best Coming-of-Age Movies On Prime Video," writing that it "dives deep into complicated themes like sadness, love, affection, sex, and regret and showcases them honestly and beautifully.

They praised Reinhart and Abrams for their "adorable chemistry" and "stellar performances," and wrote that the movie "dives deep into the science and psychology of heartbreak, what it means to move on, lose parts of ourselves, and rediscover them.