Lili Reinhart does the heavy lifting in Amazon Prime Video's new romcom The Love Hypothesis, and according to the Guardian's review, even her performance cannot save the screen adaptation of Ali Hazelwood's BookTok sensation.

The film adapts neuroscientist-turned-author Ali Hazelwood's bestselling novel, a book that became a phenomenon through BookTok's romance community. On paper, the Guardian's critic argues, the material suits Reinhart perfectly: an ideal protagonist who is "extremely nerdy, in a periodic table way, yet conventionally beautiful, awkward and self-deprecating yet cutting when it counts" — the kind of sweet-presenting young woman who will shout "fuck" repeatedly in private.

Reinhart plays Olive Smith, a young biology PhD student at Stanford. The Guardian notes the film's "unsettlingly cold open" finds a bleary-eyed Olive, rendered blind by expired contact lenses, panicking before her grad school interview before boldly declaring her cancer-solving intentions to a brusque, handsome professor in a lab bathroom.

The review situates the role within Reinhart's career trajectory since Riverdale, the CW comic soap that ended its run after giving its young cast, including Charles Melton and Camila Mendes, often absurd material to deliver with earnest conviction. Reinhart, who played Betty Cooper, emerges in the Guardian's assessment as the strongest of that talented group — "her impressively expressive eyes able to sell the unsellable with complete conviction."

The critic identifies Reinhart as "the type of helplessly endearing performer suited to roles of naivety who masks surprise steeliness," citing her notable turn in 2019's Hustlers. Yet the review also flags a persistent problem: a dearth of worthy material. A dual role in 2022's Look Both Ways, a Netflix homage to Sliding Doors, "didn't cut it," according to the critic.

The Love Hypothesis arrives as one of the most high-profile BookTok-to-screen transfers to date, a test of whether the platform's reading communities can translate their commercial power into streaming success. Hazelwood's novel, with its nerdy-romance premise rooted in academic science, built its audience on precisely the qualities Reinhart embodies on screen — awkward charm and hidden resolve.

The Guardian's verdict is measured but clear: Reinhart's committed performance is "not quite enough" to ignite the adaptation, and the film lacks the spark that made the book a hit. For an actor whose post-Riverdale career has waited on the right vehicle, The Love Hypothesis once again leaves the question of a true breakout open — even as it confirms, for the critic, that Reinhart remains capable of rising above subpar surroundings.