The the love hypothesis book has returned to the spotlight in September 2026 following the release of its Prime Video movie adaptation. Ali Hazelwood’s bestselling romance novel first arrived in the United States in 2021, introducing readers to scientist Olive Smith and Stanford professor Adam Carlsen.
The book now has a new movie tie-in edition from Berkley.
That edition went on sale September 8, 2026, ahead of the film’s September 23 debut on Prime Video. The current paperback runs 416 pages and includes new material connected to the screen adaptation.
The tie-in edition features a new foreword from Lili Reinhart, who plays Olive in the movie.
It also includes both bonus chapters from Adam’s perspective, along with exclusive movie artwork.
The original novel remains the foundation of the story.
It follows Olive, a third-year biology Ph.D. candidate, as a fake relationship with Adam gradually becomes much more complicated.
The book combines contemporary romance with graduate-school life, scientific research, friendship and the challenges faced by women in STEM.
When Was The Love Hypothesis Book Published?
Ali Hazelwood’s The Love Hypothesis was first published in the United States on September 14, 2021.
Berkley released the original U.S. edition.
The novel quickly became one of Hazelwood’s best-known works and reached the New York Times bestseller list.
The story gained attention for combining several popular romance elements.
Its central setup involves fake dating.
The characters also work in science and academia.
That combination gives the novel a setting that differs from many conventional contemporary romances.
Five years after its original publication, the book remains closely connected to Hazelwood’s growing body of STEM-focused romance.
The 2026 movie has now introduced the story to viewers who may not have read the original novel.
Who Wrote The Love Hypothesis?
Ali Hazelwood wrote The Love Hypothesis.
Hazelwood has an academic background in neuroscience.
She originally comes from Italy and later moved to the United States to pursue a Ph.D. in neuroscience.
Her scientific background strongly influences her fiction.
Many of her stories feature women working in science, technology, engineering or mathematics.
That focus is particularly important in The Love Hypothesis.
Olive is not simply a character who happens to study science.
Her research career is central to her identity.
Her academic ambitions influence many of the decisions she makes throughout the novel.
What Is The Love Hypothesis About?
The novel follows Olive Smith, a third-year Ph.D. candidate in biology at Stanford.
Olive does not believe that lasting romantic relationships are particularly important to her life.
Her best friend, Anh, has a very different view.
Anh develops feelings for Jeremy, who is also connected to Olive’s past.
Olive wants her friend to feel free to pursue that relationship.
The problem is that Anh knows Olive previously liked Jeremy.
Olive therefore needs to prove that she has moved on.
Her solution is impulsive.
She kisses the first man she sees.
That man turns out to be Adam Carlsen, a young Stanford professor with a reputation for being difficult.
Adam agrees to pretend to be Olive’s boyfriend.
The arrangement appears simple at first.
Neither expects it to become emotionally complicated.
As they spend more time together, however, their carefully defined boundaries become harder to maintain.
Who Is Olive Smith?
Olive Smith is the main character in the novel.
She is a biology Ph.D. candidate at Stanford.
Her scientific career matters deeply to her.
Olive spends much of her time thinking about research, academic opportunities and her future.
Her personal life becomes complicated when she creates the fake relationship with Adam.
She initially sees the arrangement as a practical solution.
It should allow Anh to pursue Jeremy without worrying about Olive.
Instead, the arrangement creates an entirely new set of problems.
Olive’s feelings begin to change.
She also discovers that her first impression of Adam does not tell the entire story.
Her character combines scientific ambition with emotional uncertainty.
That contrast drives much of the novel.
Who Is Adam Carlsen?
Adam Carlsen is the male lead.
He is a Stanford professor known for his intimidating personality.
Students and colleagues view him as demanding.
Olive initially has little reason to expect him to become involved in her personal life.
The situation changes when she impulsively kisses him.
Adam agrees to participate in her fake-dating plan.
The arrangement gives both characters reasons to maintain the appearance of a relationship.
Adam’s character becomes more complex as Olive gets to know him.
The professor she initially fears is not exactly the person she imagined.
His support also becomes important when Olive faces difficulties involving her scientific career.
Adam’s relationship with Olive forms the central romantic storyline.
Who Is Anh Pham?
Anh Pham is Olive’s best friend.
She plays an important role in the novel because her romantic situation helps trigger Olive’s fake relationship.
Anh develops feelings for Jeremy.
Olive wants to support her.
She also does not want Anh to feel guilty about dating someone Olive once liked.
That leads Olive to create the impression that she is already dating someone else.
Anh’s friendship with Olive remains important throughout the story.
The novel therefore does not focus only on romantic love.
Friendship plays a major role as well.
That aspect has also remained important in the 2026 movie adaptation.
Rachel Marsh plays Anh in the Prime Video film.
Who Is Jeremy Langley?
Jeremy Langley is connected to both Olive and Anh.
Olive previously had feelings for him.
Anh develops an interest in Jeremy.
This creates the situation that eventually leads Olive toward Adam.
Olive’s decision to prove that she has moved on starts the chain of events.
Her impulsive kiss becomes the beginning of her fake relationship.
Jeremy therefore plays an important role in the setup of the novel.
He is not the eventual romantic partner at the center of the story.
That position belongs to Adam.
The Fake-Dating Romance
Fake dating provides the basic structure for Olive and Adam’s relationship.
Olive needs a boyfriend for a specific reason.
Adam agrees to help her.
They create rules around their arrangement.
Those rules are supposed to keep the situation controlled.
Instead, spending time together gradually changes their relationship.
The two characters begin to understand each other differently.
The fake relationship creates opportunities for them to interact outside their normal academic roles.
It also creates tension because their public relationship does not always match their private feelings.
The romance develops from that conflict.
Science and Romance Come Together
Science is one of the defining elements of the novel.
Olive is a biology researcher.
Adam is a professor.
Their professional lives overlap within the Stanford academic environment.
Hazelwood uses this setting throughout the story.
The characters discuss research and academic careers.
They also face professional pressures that affect their personal lives.
This approach gives the romance a clear identity.
The scientific setting is not simply decoration.
It shapes the characters and their choices.
Olive’s Life as a Ph.D. Candidate
Olive’s status as a Ph.D. candidate is important throughout the story.
Graduate school can involve demanding research schedules, professional competition and uncertainty about the future.
Olive experiences those pressures.
She wants to establish herself as a scientist.
Her relationship with Adam develops while she is trying to achieve that goal.
This keeps her career at the center of the novel.
Olive’s story is therefore about more than finding a romantic partner.
It also follows her efforts to build a professional future.
Adam’s Position at Stanford
Adam’s career creates a contrast with Olive’s.
He is already a professor.
Olive remains a student working toward her doctorate.
His established position gives him a different level of authority within the academic environment.
That difference affects their relationship.
Adam’s reputation also shapes Olive’s first impression of him.
She expects him to be cold and intimidating.
Her experience with him eventually becomes more complicated.
The contrast between Adam’s professional reputation and his personal relationship with Olive drives much of the romance.
The Science Conference
A major event in the novel involves a scientific conference.
The conference becomes important to Olive’s professional storyline.
Her career faces challenges surrounding the event.
Adam’s support becomes particularly important during this part of the story.
The conference also brings professional and personal issues together.
Olive’s relationship with Adam cannot remain completely separate from her academic ambitions.
That connection gives the novel stakes beyond its romance.
Women in STEM
Women working in STEM careers remain central to Hazelwood’s fiction.
The Love Hypothesis is one of her clearest examples.
Olive is a woman pursuing a doctoral degree in biology.
Her career is not secondary to the romance.
She wants to succeed in science.
She also faces the professional environment that comes with working in academia.
Hazelwood’s own scientific background informs the setting.
The result is a romance that treats the characters’ professional identities as meaningful parts of their lives.
The Importance of Friendship
Olive and Anh’s friendship is a major part of the story.
The entire fake-dating setup begins because Olive wants to help Anh.
That motivation distinguishes the relationship from a simple romantic triangle.
Olive is willing to make an uncomfortable decision for her friend.
The friendship continues to influence Olive’s choices.
The 2026 adaptation has also emphasized this element.
Lili Reinhart and Rachel Marsh have discussed the importance of Olive and Anh’s relationship.
That makes the friendship one of the book’s defining relationships.
The Book’s Fan-Fiction Origins
The Love Hypothesis has an unusual publishing history.
Before becoming an original novel, the story began as Star Wars fan fiction written by Hazelwood.
The early version centered on characters based on Rey and Kylo Ren.
Hazelwood later transformed the story into an original work.
The published novel contains original characters, including Olive Smith and Adam Carlsen.
The connection to Star Wars remains part of the novel’s history.
The 2026 film has brought renewed attention to that background.
Tom Bateman plays Adam in the movie.
His wife, Daisy Ridley, played Rey in several Star Wars films.
That connection became a notable part of the film’s casting story.
Lili Reinhart’s Connection to the Novel
Lili Reinhart plays Olive in the 2026 movie.
She had read Hazelwood’s novel before joining the project.
Reinhart has spoken about her connection to the characters.
She also highlighted the friendship between Olive and Anh.
Her involvement goes beyond acting.
She serves as an executive producer on the movie.
She also wrote a new foreword for the 2026 movie tie-in edition of the book.
That makes Reinhart directly connected to both the original literary story and its screen adaptation.
Rachel Marsh Read the Book Before Playing Anh
Rachel Marsh plays Anh in the movie.
She also read the novel before taking on the role.
Marsh has discussed being drawn to the friendship between Anh and Olive.
That relationship helped her understand Anh’s role within the story.
The actress has also described the book as an important part of her preparation.
Her participation connects the literary version of Anh with the screen adaptation.
The 2026 Movie Tie-In Edition
The current movie tie-in edition represents the biggest recent update for readers.
Berkley released the paperback on September 8, 2026.
It contains 416 pages.
The edition has ISBN 9798217195633.
Its cover features artwork connected to the Prime Video movie.
The interior also includes additional movie-themed artwork.
More importantly, the edition contains new reading material.
It includes a foreword by Lili Reinhart.
It also contains both bonus chapters from Adam’s perspective.
Those chapters give readers additional insight into Adam’s side of the story.
What Is New in the Movie Tie-In Book?
The main story remains Hazelwood’s original novel.
The new edition adds several features connected to the adaptation.
Readers get:
- A new foreword by Lili Reinhart
- Exclusive movie artwork
- Additional artwork inside the front and back covers
- Two bonus chapters from Adam’s perspective
- The complete original novel
The Adam chapters are particularly notable.
The original story largely follows Olive’s perspective.
The additional chapters give readers more access to Adam’s thoughts.
That makes the tie-in edition useful for readers who want more material about the central romance.
How Many Pages Is The Love Hypothesis Book?
Page counts vary by edition.
The original 2021 U.S. paperback contains 400 pages.
The current 2026 Prime Tie-In paperback contains 416 pages.
The difference comes from the additional material and the new edition’s formatting.
The 2026 tie-in edition is therefore longer than the original paperback.
The hardcover edition released in June 2026 has 384 pages.
Readers should check the ISBN when buying the book because different editions can have different page counts.
The Love Hypothesis Book Editions
Several editions of the novel are currently associated with the U.S. market.
| Edition | Publication date | Format | Pages |
|---|---|---|---|
| Original U.S. edition | September 14, 2021 | Paperback | 400 |
| 2026 edition | June 30, 2026 | Hardcover | 384 |
| Prime Tie-In | September 8, 2026 | Paperback | 416 |
| Original digital edition | September 14, 2021 | Ebook | 384 |
| Original audiobook | September 14, 2021 | Audiobook | 11 hours 52 minutes |
Edition details can vary by format.
The Prime Tie-In is the edition most directly connected to the current movie.
The Love Hypothesis and the 2026 Movie
The movie adaptation premiered on Prime Video on September 23, 2026.
Lili Reinhart plays Olive.
Tom Bateman plays Adam.
Rachel Marsh plays Anh.
Nicholas Duvernay plays Jeremy.
The film was directed by Claire Scanlon.
Sarah Rothschild wrote the screenplay.
The movie brings Hazelwood’s characters into a feature-length adaptation.
The central fake-dating setup remains part of the screen story.
The film also retains the scientific and academic environment that defines the novel.
Differences Between the Book and Movie
The film is an adaptation rather than a scene-for-scene reproduction.
Some characters and scenes from the book do not appear in the same way on screen.
The movie also places additional emphasis on Olive and Anh’s friendship.
Director Claire Scanlon has discussed the friendship as an important part of the adaptation.
That focus reflects one of the central relationships in the novel.
Readers should therefore expect the movie to tell the same core story while making changes for the screen.
The book remains the longer and more detailed version of Olive and Adam’s story.
Why the Book Matters to the 2026 Adaptation
The novel is the source material for the movie.
It establishes Olive’s personality.
It introduces Adam’s academic reputation.
It creates the friendship between Olive and Anh.
It also establishes the fake-dating arrangement.
The screenplay then translates those elements into a visual format.
The book therefore remains essential for understanding the original version of the story.
Readers who watch the movie can also return to the novel to explore the characters in greater depth.
Ali Hazelwood’s Scientific Background
Hazelwood’s scientific education plays an important role in her writing.
She pursued a Ph.D. in neuroscience.
Her professional experience gives her familiarity with academic research.
That background appears throughout The Love Hypothesis.
The novel treats scientific work as part of the characters’ everyday lives.
Olive’s career ambitions feel central to her character.
Adam’s position also places him within the same professional environment.
The scientific setting helps define the tone and identity of the novel.
The Book’s Romance Tropes
The novel combines several popular contemporary romance elements.
Its most recognizable tropes include:
- Fake dating
- Slow-burn romance
- Academic romance
- STEM romance
- Opposites-attract dynamics
- Friendship
- Workplace tension
The fake relationship provides the story’s main structure.
The academic setting creates additional complications.
The friendship between Olive and Anh provides the emotional foundation.
Together, these elements create the novel’s distinctive romantic setup.
Why Readers Continue to Discuss the Novel
The book continues to attract attention because its central setup is easy to understand while its characters have professional ambitions.
Olive is a scientist.
Adam is a professor.
Their relationship begins as an arrangement.
Their feelings develop gradually.
The story also gives significant attention to Olive’s friendship with Anh.
Those elements give the novel several relationship dynamics rather than relying only on the main romance.
The 2026 movie has now introduced those characters to a wider streaming audience.
The Love Hypothesis Book in September 2026
The love hypothesis book remains closely connected to the new Prime Video adaptation.
The original novel arrived in September 2021.
The current movie tie-in paperback went on sale September 8, 2026.
It contains 416 pages and features a new foreword from Lili Reinhart.
It also includes both Adam’s-perspective bonus chapters.
The film premiered on Prime Video on September 23, 2026.
That timing has brought renewed attention to Hazelwood’s original novel.
Readers who discovered Olive and Adam through the movie can now return to the source material.
Longtime fans also have a new edition with additional content.
The story remains centered on Olive Smith, a biology Ph.D. candidate, and Adam Carlsen, a Stanford professor.
Their fake relationship begins as a solution to a friendship problem.
It gradually becomes much harder for either character to treat it as an experiment.
The book’s combination of romance, science, friendship and academic life remains at the heart of its appeal.
The Cast of The Love Hypothesis article provides additional details about Lili Reinhart, Tom Bateman, Rachel Marsh, and the supporting cast.
Have you read The Love Hypothesis book before watching the 2026 movie? Share your favorite Olive and Adam moment in the comments and stay tuned for the latest updates.