The first season, consisting of ten episodes, premiered on Netflix on September 29, 2017, and the second season was released on October 5, 2018. The third season was preceded by a Valentine's Day special episode on February 8, 2019, and the rest of the third season was released on October 4, 2019. In July 2019, Netflix renewed the series through to a sixth season. The fourth season was released on December 4, 2020, and the fifth season was released on November 5, 2021. A seventh season was ordered in April 2022.
Upon its release, the series received critical acclaim, with praise going to the writing, animation, voice acting, musical numbers, humor, and emboldening messages of acceptance.
The series follows a group of teenage 7th graders, including best friends Nick Birch and Andrew Glouberman, as they navigate their way through puberty with struggles like masturbation and sexual arousal all in the Westchester Countysuburbs of New York. Acting as over-sexualized shoulder angels are the hormone monsters: Maurice (who pesters Andrew and Matthew and occasionally Nick), Connie—the hormone monstress (who pesters Jessi and Nick and occasionally Missy) and Mona (who mainly pesters Missy). Throughout the series, the kids interact with people and objects who are often personified and offer helpful, yet confusing, advice in their puberty-filled lives including the ghost of Duke Ellington, a French-accented Statue of Liberty, a pillow capable of getting pregnant, a bar of Adderall, and even Jessi's own vulva. They seek out their destiny as puberty challenges them mentally and physically.
Nicholas Arsenio "Nick" Birch, an adolescent boy living with his loving and open-minded parents. He also has an older brother named Judd and an older sister named Leah. Throughout the series, Nick is increasingly insecure about his masculinity and overall development as it becomes evident that he is a late bloomer compared to his friends. Occasionally, he learns to appreciate his body and his emotions, with the help of his loved ones and a few other figures.
Maurice the Hormone Monster, also known as "Maury", full name Maurice Beverley, is a raspy-voiced monster who follows Andrew around and is responsible for his brooding sexual desires, which frequently occur at inappropriate moments. He is revealed to hail from an alternate dimension where several different creatures, such as himself, represent and manage the stages of human life. He is shown to be able to interact with other boys, such as Nick and Jay. He is also Matthew's hormone monster.
Coach Steve, the shrill-voiced middle school gym class teacher who is incompetent and overly talkative, often trying to get his colleagues—or even the students—to hang out (often to no avail). He is extremely childlike. It is revealed in season 2 that he is a virgin, though he ultimately loses his virginity to Jay's mom, with whom he has a one-night stand after she sexually approaches him. He is the only character unaffected by The Shame Wizard because he is incapable of experiencing shame. In season 3, he has a different job every time he appears until in the episode "Disclosure the Movie: The Musical!" he gets his job back as a gym coach.
Rick the Hormone Monster, an old, dysfunctional yet enthusiastic hormone monster who follows Coach Steve and later Nick. He soon retires, however, after Steve loses his virginity, handing his position as Nick's hormone monster to Tyler. He becomes Nick's hormone monster again after Nick and Connie part ways.
Lola Ugfuglio Skumpy, an ill-tempered popular girl who is terrified of losing her social status and the approval of her best friend Devin. She has a relationship with Jay in season 4, but it ends badly. Her relationship with Jay becomes on again-off again in the following season.
Nick Starr, the future version of Nick who hosts a game show and lives alone with a robot version of Andrew.
Kroll also appears as himself in live-action in the season five finale, as the person in charge of Human Resources.
John Mulaney as Andrew Glouberman, a young boy and Nick's best friend who spends much of his time furtively masturbating. He is Jewish and his dysfunctional family annoys him. But with the help of Maury, he had a secret anthology of Puberty. In season 4, he went to Summer Camp and bullied Nick, giving him the nickname "soup". He may or may not be bisexual. Despite conclusively discovering he is not gay in season 1, in subsequent seasons, he appears to be very attracted to male figures such as Michael Angelo and Mr. Keating.
Mulaney also voices Mint, Grandpa Andrew, Babe the Blue Ox, and Detective Florez.
Jessi Klein as Jessica Cobain "Jessi" Glaser, a sarcastic and smart girl. Her father, Greg, is an unemployed stoner and her mother, Shannon, is secretly dating another woman. She gets her period for the first time on a school trip to the Statue of Liberty. Though Jessi has kissed Nick before, specifically in the first episode "Ejaculation", she later has many French kissing make-out sessions with Jay. Like Andrew, she is Jewish, as she has a Bat Mitzvah in "I Survived Jessi's Bat Mitzvah".
Klein also voices Jessi's possible ancestor, Margaret Daniels, in "Duke".
Jason Mantzoukas as Jayzerian Ricflairian "Jay" Bilzerian, a brash teenage boy who is obsessed with magic and sex. He has sex with a pillow that he made into a sex toy. His mom allows Coach Steve to have a one-night stand with her in Season 2. He has two older brothers, Kurt and Val, who frequently bully him. His dad is a divorce lawyer, and Jay has a habit of quoting his father's law commercials, often being told by his friends to stop. Jay is obsessed with Nick's mother and father and wishes for a loving family. In season 2, Jay shares a kiss with Matthew, an openly gay boy in school, during a game of "Smooch or Share". After the two kiss, Jay questions his sexual orientation. During season 3, Jay continues to question his sexual orientation but comes to the conclusion he is bisexual. In Season 5, Matthew breaks up with Aiden because he has truer feelings for Jay. Jay and Matthew decide to go to Devin and Devon's New year's party together.
Mantzoukas also voices Guy Bilzerian, Jay's father who is a corrupt divorce lawyer, and the landlord of a seedy all-men motel called "Guy Town". His commercials are well known in the neighborhood and Jay takes every opportunity he can to quote them, to the ire of his classmates.
Jenny Slate (seasons 1–4) and Ayo Edebiri (seasons 4-present) as Melissa "Missy" Foreman-Greenwald, a nerdy and kind girl who is a frequent target of Andrew's affection. Missy sometimes has trouble relating to her peers due to her sheltered upbringing and general naiveté, but during Season 3, she starts to mature (both physically and emotionally) and eventually gains her own hormone monster, Mona. In Season 4, Missy also begins exploring (and more deeply embracing) her African-American heritage.
Slate also voiced Mirror Missy, Missy's verbally abusive reflection, meant to represent the insecurities over her body, as well as Missy's repressed anger.
Slate also voices Vicky, Cherry's delinquent friend.
Slate also voices Taffiny, a pharmacist, a Planned Parenthood nurse, Ms. Razz, The Implant, the Fuck Gremlin, Matthew's sister, Britney, and Greg's new girlfriend, Kaitlyn.
Slate stepped down as Missy's voice actress near the end of Season 4, believing the role of an African-American character should be voiced by an African-American actress.
Edebiri is initially heard as Mosaic Missy, an amalgamation of all of Missy's different alter-egos and personality traits.
Fred Armisen as Elliot Birch, Nick's loving father, who frequently shares inappropriate stories.
Armisen also voices the ghost of Antonin Scalia, a bus driver, Stavros, and Bob the Hormone Monster.
Connie the Hormone Monstress, full name Connie LaCienega, who initially follows Jessi (and sometimes Missy) around and encourages them to embrace their wildest desires. By the end of the second season, she becomes Nick's hormone monster, despite him being a boy, which works well with them both.
Diane Birch, Nick's loving mother.
Bonnie LaCienega, Connie's twin sister, and Leah's hormone monster. Bonnie is a little more uptight than her twin sister and has an extreme dislike of Maury.
Joe Wengert as Caleb, a student, implied to be on the autism spectrum.
Wengert also voices Lump Humpman, a priest, and Stan the Hormone Monster.
Fran Gilesspie as Samira, a student who speaks quietly and begins dating Ali.
Jon Daly as Judd Birch, the dark yet caring older brother of Nick and Leah Birch, and the son of Diane and Elliot Birch. In "Nick Starr", the Judd of 2052 now rules over "Juddstown", offering sanctuary the day before the end of the world.
TV writer Andrew Goldberg and screenwriter-directors Jennifer Flackett and Mark Levin approached Nick Kroll, Goldberg's best friend since childhood, with the idea to develop a show about going through puberty. Kroll and Goldberg used their divergent pubertal experiences as a centerpiece of the show, because Kroll was a late bloomer while Goldberg went through the physical changes of puberty very early. Many of their lived experiences are featured in the show, such as Kroll's first kiss, and Goldberg's parents waxing his mustache. The show also includes an experience of their childhood friend, Lizzie, who the character of Jessi is based on, getting her first period on a school trip to the Statue of Liberty. According to Kroll in an interview on NPR, Big Mouth "takes an equal look at what it's like for girls and women, the process of going through puberty, which I think has not been quite as explored in most popular culture." Netflix announced they had picked up Big Mouth in June 2016.
On June 24, 2020, it was announced that Jenny Slate decided to step down from voicing Missy Foreman-Greenwald so that a Black actress could have the role in the wake of the George Floyd protests. Slate's final time voicing Missy is in the fourth season as she recorded her lines in advance. On August 28, 2020, it was reported that Ayo Edebiri was cast to replace Slate as Missy. Her first appearance as Missy is in "Horrority House", the penultimate episode of the fourth season.
The first season, consisting of ten episodes, premiered on Netflix on September 29, 2017. On October 24, 2017, it was confirmed that a second season had been ordered, which was released on October 5, 2018. On November 17, 2018, Netflix announced that Big Mouth had been renewed for a third season. The third season was preceded by a Valentine's Day special episode on February 8, 2019. On July 26, 2019, Netflix renewed the series through to a sixth season. On August 21, 2019, it was reported that the third season was set to be released on October 4, 2019. The fourth season was released on December 4, 2020. The fifth season was released on November 5, 2021. In April 2022, Netflix renewed the show for a seventh season, ahead of the sixth season premiere. The sixth season is due to premiere sometime in 2022.
Big Mouth has received critical acclaim since its release. On Rotten Tomatoes, the first season has an approval rating of 100% based on 23 reviews, with an average rating of 8.10 out of 10. The website's critics consensus reads, "Big Mouth's simplistic animation and scatological humor belie its finely sketched characters and smart, empathetic approach to the messiness of adolescence." On Metacritic, it holds a rating of 80 out of 100, based on six critics, indicating "generally favorable reviews".
On Rotten Tomatoes, the second season has an approval rating of 100% based on 33 reviews, with an average rating of 8.80 out of 10. The website's critics consensus reads "Poignantly repulsive, Big Mouth continues to confront the awkwardness of adolescence with foul-mouthed glee and an added layer of maturity." On Metacritic, it has a score of 90 out of 100 for the second season, based on nine critics, indicating "universal acclaim".
On Rotten Tomatoes, the third season has an approval rating of 97% based on 33 reviews with an average rating of 8.00 out 10. The website's critics consensus reads, "Like the characters at its center, Big Mouth's third season continues to grow, taking on complicated new issues with the same gross-but-utterly-empathetic eye that made it so lovable in the first place." On Metacritic, it has a score of 84 out of 100 for the third season, based on five critics, indicating "universal acclaim".
On Rotten Tomatoes, the fourth season has an approval rating of 100% based on 22 reviews, with an average rating of 8.30 out of 10. The website's critics consensus reads, "Big Mouth's fourth season is another tour de force of empathetic cringe comedy that manages to get even better by finally giving Missy the storyline she deserves." On Metacritic, it has a score of 88 out of 100 for the fourth season, based on four critics, indicating "universal acclaim".
On Rotten Tomatoes, the fifth season has an approval rating of 100% based on 5 reviews
Vox described the first season as sharp and jarring depicting the awkwardness of pubescence, post-pubescence, and pre-pubescence. Erik Adams from The A.V. Club awarded the second season an "A−". Adams praised the cast, especially Thewlis, and the experimentation of this season, commenting that "it's shown that it deserves to be included in any conversation about TV's animated greats."
On October 3, 2019, Netflix announced a straight-to-series order for a spin-off series titled Human Resources, set within the show's universe. Kroll, Goldberg, Levin, Flackett and Kelly Galuska will produce. On June 14, 2021, more details of the series were announced, including casting. Kroll, Rudolph, Thewlis, Bryant, Cannavale, Newton, Bamford, Goodman, Palmer, Clement and Adlon reprised their roles for the spin-off, with additional cast members Randall Park, Rosie Perez, and Henry Winkler joining the series. It was released on March 18, 2022.