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Regular-Irregular

Regular-Irregular is the first studio album by South Korean boy band NCT 127, a sub-unit of the project NCT. It was released on October 12, 2018, by SM Entertainment and distributed by IRIVER. The album marks NCT 127's first Korean-language full-length release since their 2017 EP Cherry Bomb and their first as a ten-member group following the addition of Jungwoo. It contains eleven tracks, including the lead single "Regular", spanning genres such as hip hop, R&B, and EDM, and is conceptually divided into "regular" (reality) and "irregular" (dream world) halves. The album debuted at number one on the Gaon Album Chart and number 86 on the US Billboard 200, becoming NCT 127's highest-charting release in the United States at the time. It has been praised for its experimental sound and versatility, with Billboard ranking it 15th among the best K-pop albums of 2018. A repackage album titled Regulate, featuring three new tracks including "Simon Says", followed on November 23, 2018.

Background and development

Original album

The original album Regular-Irregular by was released digitally on October 12, 2018, worldwide through on platforms including and . This marked the group's first full-length studio album, available for streaming and download immediately upon release at 6 p.m. KST. Physical copies were also issued on October 12, 2018, in by in CD , featuring two main versions: and Irregular, each with distinct artwork and inclusions such as a , , and random photocard. The Korean edition carried the catalog number SMK 1033. availability followed shortly after, with imports distributed globally, enabling the album to debut at number 86 on the US Billboard 200 chart the following week. Physical releases were primarily through Korean retailers and online exporters, without dedicated region-specific variants under labels like Capitol or Avex at the time of launch. The album was offered exclusively in format for its original 2018 rollout, with no limited cassette editions or pressings produced contemporaneously; later reissues in 2021 included updated member-specific covers but retained the medium. This physical presentation emphasized collectible elements tailored to the market, aligning with the promotional timeline that began with teaser images and the "Regular" on October 9.

Repackage (Regulate)

Following the commercial success of their debut studio album Regular-Irregular, which sold over 250,000 physical copies in within its first month and debuted at No. 86 on the , announced a repackage edition titled Regulate in mid-November 2018. The repackage aimed to extend the original's momentum by incorporating fresh material while maintaining the thematic exploration of balancing "regular" and "irregular" elements in NCT's multifaceted concept. The Regulate edition added three new tracks recorded in late 2018: the "Simon Says," an urban hip-hop song with heavy bass and synth elements; "Welcome to My Playground," an upbeat collaboration featuring songwriting contributions from Ra.D and Brother'Su; and the Korean-language version of "," originally from NCT 127's Japanese mini-album. "" was produced by a team including Ronny Svendsen, Anne Judith Stokke Wik, and SM Entertainment's , emphasizing intense choreography and dynamic vocal performances, particularly highlighting main vocalist Jaehyun's range in the high-energy verses and chorus. The new songs showcased the group's evolving sound, with "Welcome to My Playground" incorporating verses from members Taeyong and alongside melodic hooks. The repackage included an updated photobook featuring winter-themed visuals, capturing NCT 127 in snowy, festive settings to align with the late-year release timing. This aesthetic shift complemented the original's urban motifs, providing fans with refreshed packaging across multiple versions. Additionally, the project marked increased prominence for member Jungwoo, who had joined the lineup for Regular-Irregular just a month prior, allowing him fuller integration into promotions and . SM Entertainment's release strategy for Regulate targeted the holiday season, with the digital version launching on November 23, 2018, and physical copies following on November 27, to maximize year-end sales and global streaming during festive periods. The timing capitalized on the group's growing international fanbase, built from the original album's U.S. promotions, while Winwin's absence due to scheduling conflicts for his preparations shifted focus to the remaining nine members.

Musical style and composition

Original album

Regular-Irregular is a multi-genre that explores themes of ("regular") and unpredictability ("irregular") through its tracklist, divided conceptually into structured and experimental sides. The album incorporates elements of , R&B, pop, , and , creating a cinematic that blends high-energy rhythms with introspective moments. The "Regular" is a high-energy track infused with sensual vibes, featuring Spanish phrases and a pulsating beat to evoke rebellion against routine. "Interlude: Regular to Irregular" transitions the album's duality with production, including multilingual narrations in , , , and English to bridge the thematic sides. Other notable tracks include the R&B-infused "Touch," the upbeat pop-dance "City 127," and the emotional "Come Back," a Korean adaptation of a prior Japanese release, which emphasizes vocal harmonies and minimalistic instrumentation. Overall, the production highlights NCT 127's vocal and rap dynamics, with 11 tracks totaling around 40 minutes, mixing Korean and English lyrics for broader appeal.

Repackage additions

The repackage Regulate adds three new tracks that expand the original's thematic duality of structure versus chaos, incorporating more electronic and elements to enhance rhythmic intensity and global accessibility. "," the lead single, is an experimental track with EDM and influences, characterized by sparse melodies, addictive hooks, and commanding rap verses that play on control and temptation. "Welcome to My Playground" is a and R&B song featuring prominent sections by Taeyong and Mark, with funky soul elements and a playful, inviting that delves into and personal invitation. "Chain (Korean Version)" brings R&B and sensibilities, with layered vocals, subtle electronic builds, and themes of unbreakable bonds, adapting the group's earlier Japanese single into a more intimate, harmony-driven piece.) These additions, alongside an English version of "Regular," shift the album toward greater emphasis on English content and dance-oriented sounds, fostering a cohesive evolution from the original's divided structure to a more unified, internationally oriented collection.

Singles and promotion

Lead single "Regular"

"Regular" served as the lead single for NCT 127's debut studio album Regular-Irregular, with the English version released digitally on October 9, 2018, and the Korean version on October 12, 2018, alongside the full album to target international and domestic audiences. The English version's music video premiered on October 8, 2018, on the group's official YouTube channel, showcasing high-energy urban choreography amid a dystopian school setting that twists traditional uniform concepts into chaotic, "irregular" scenarios symbolizing rebellion against conformity. The Korean version's music video followed on October 11, 2018, directed by Wooje Kim of etuicollective, emphasizing synchronized dance moves and intense visuals to highlight the track's Latin trap influences and the group's dynamic performance style. Promotions for "Regular" began on the album's release date of October 12, 2018, with live performances on major music shows starting that week. NCT 127 first appeared on KBS's Music Bank on October 12, delivering a high-impact stage that incorporated the song's edgy choreography and school-uniform theme reimagined as disruptive, irregular antics. Subsequent performances included SBS's on October 14, MBC's on October 20, SBS MTV's The Show on October 16 and 23, Mnet's on October 17 and 25, and Music Bank again on October 26, aligning with the album's overall promotion timeline of intense weekly showcases to build momentum. The concept emphasized a of breaking free from "regular" norms, with members donning altered school attire to convey youthful defiance through sharp formations and powerful vocals. The single achieved commercial success, topping the Gaon Album Chart for two weeks and earning four music show wins: first place on SBS MTV's The Show on October 16 and 23, 2018, Mnet's M Countdown on October 25, and KBS's Music Bank on October 26. These accolades underscored the track's impact within the K-pop landscape, contributing to the album's broader visibility.) "Regular" was positioned as the primary lead single to introduce the Regular-Irregular duality theme, with packaging and highlight medleys hinting at interconnected narratives across tracks. This strategic reveal built anticipation for the full album, blending urban hip-hop elements before additional tracks were unveiled in the repackage.

Other promotional activities

The promotional campaign for NCT 127's debut studio album Regular-Irregular commenced on September 17, 2018, with the release of teaser images featuring the full 10-member lineup, including new addition Jungwoo, alongside an announcement of the album's October 12 release date. This initial reveal highlighted the album's dual "Regular" and "Irregular" concept, blending everyday reality with surreal elements, and generated significant fan anticipation through visual motifs of urban and dreamlike aesthetics. To engage fans further, NCT 127 hosted sessions in late September and early October 2018, including a highlight medley reaction and commentary where members elaborated on the "Irregular" themes of and self-discovery across the album's tracks. These online broadcasts allowed direct interaction, with the group sharing insights into the multi-genre and arc, fostering deeper conceptual understanding among global audiences. The showcase concert, titled "NCT 127 1st Album Showcase," took place on October 11, 2018, serving as a pre-release event to preview performances and interact with media and fans. Additionally, cross-promotions with NCT U subunits occurred during the 2018-2019 award season, such as joint stages at the , where NCT 127's "Regular" performance complemented NCT U's contributions, amplifying the broader NCT project's visibility. For the repackage album Regulate, released digitally on November 23, 2018, promotions emphasized the three new tracks—"Simon Says," "City 127," and "Welcome to My Playground"—with the music video for "Simon Says" launching on the same day to spotlight the album's intensified trap and hip-hop influences. "Simon Says" promotions included performances on SBS MTV's The Show (November 27), MBC Music's Show Champion (November 28), Mnet's M Countdown (November 29), SBS's Inkigayo (December 2), and KBS's Music Bank (December 7). Tied to these efforts, NCT 127 embarked on their first Japan concert tour in November 2018, performing selections from both Regular-Irregular and Regulate to capitalize on growing international interest, including fan events that featured album-themed content. In mid-2019, member Doyoung appeared on King of Mask Singer in July, delivering masked vocal performances that indirectly supported NCT 127's rising profile during the post-repackage period. Further media outreach included Japanese TV appearances promoting "Highway to Heaven" from their subsequent mini-album, aligning with ongoing Regulate-era momentum through bilingual content and live stages.

Release and formats

Original release

The debut studio album Regular-Irregular by was released on October 12, 2018, by . It was made available in two physical editions—Regular and Irregular—each featuring a distinct measuring approximately 21.6 cm by 27.7 cm and containing 48 pages of concept . The standard physical package for both versions included a , a 12-page lyrics booklet, one random photocard out of 10 possible designs, and one random out of 10. Some editions also came with a folded poster. The standard edition was priced at around 16,300 KRW. A digital version of the album was simultaneously released on major streaming platforms, including and , facilitating global access. This marked NCT 127's first significant entry into the U.S. market via , enhanced by the inclusion of an English-language version of the "Regular," which broadened its appeal to international audiences. In its first week of release, Regular-Irregular sold 142,195 physical copies in according to Hanteo Chart data, setting a new record for the group at the time. The has since sold over 230,000 copies in as of 2020 ().

Regulate repackage

The Regulate repackage edition of NCT 127's debut studio Regular-Irregular was released digitally on , 2018, and in physical formats on November 27, 2018. This edition introduced ten distinct member cover versions, each featuring a different group member on the front cover to appeal to fans' preferences. The packaging enhancements included a CD, a 48-page showcasing new photoshoots of the members, one random photocard selected from ten types (one per member), and a folded available as a first-press benefit. Expanding on the original 11-track album, Regulate added three new songs—"" (the ), "Welcome to My Playground," and "Chain (Korean Ver.)"—bringing the total to 14 tracks and refreshing the project's sound with additional and elements. The digital version updated the album's presence on streaming platforms, ensuring the new tracks were integrated into existing playlists and services. The distribution strategy focused on maintaining fan engagement post the original release through targeted incentives, such as the exclusive folded for early buyers, distributed via major retailers. This approach helped sustain promotional momentum, resulting in 75,154 copies sold during the first week per Hanteo data. The later received a certification from the Music Content Association () in November 2022 for cumulative shipments exceeding 250,000 copies.

Critical reception

Original album reviews

Upon its release in October 2018, NCT 127's debut studio album Regular-Irregular received generally positive reviews from critics, who commended its ambitious exploration of contrasting themes through . highlighted the album's genre versatility, describing it as a "cinematic" soundscape that jumps between , , and other styles across its 11 tracks, while praising the group's tight synchronization among the 10 members in delivering cohesive performances. The "" was frequently singled out as a standout, with outlets like noting its and trap-infused production, suspenseful build-up, and punchy rap breaks that contribute to a club-ready energy. The album's dual structure—divided into a "regular" side representing reality and an "irregular" side evoking fantasy—was appreciated for showcasing the group's range, though some reviewers pointed to the overambitious concept resulting in uneven pacing, particularly in the first half where tracks felt less dynamic compared to the more experimental latter portion. KpopReviewed echoed this, assigning lower marks to certain "regular" tracks like the Korean version of "" (6/10) amid stronger and pop elements elsewhere, leading to an overall album score of 8.2/10. Aggregate scores reflected this balance, with awarding 8.5/10 for the innovative framework and emphasizing how the "Irregular" tracks, such as "Come Back" and "Run Back 2 U," elevated NCT 127's maturity through frantic synths, vocal harmonies, and genre-blending experimentation. Internationally, U.S.-based coverage from and commended the inclusion of an English version of "Regular," which enhanced accessibility and broadened appeal beyond listeners by maintaining the original's inflections while adapting lyrics for global audiences.

Regulate reviews

The repackage album Regulate, released on November 23, 2018, as an extension of NCT 127's debut studio album Regular-Irregular, garnered generally positive , with reviewers highlighting the new tracks' contributions to the project's dynamism. Building on the original album's critical baseline of praise for its cinematic genre-blending and exploration of reality versus fantasy, Regulate included fresh urban and elements in its additions. Critics particularly lauded the new tracks for their vibrant production and member showcases. "," the lead single, was praised for its infectious Caribbean trap rhythm, heavy bass, and sharp synths that facilitated strong and vocal performances, earning a 9/10 rating for its fun, dance-oriented appeal. Similarly, "Welcome to My Playground" received acclaim as a bright, bilingual track with a bold chorus and energetic raps by and Taeyong, scoring 9/10 for its playful tone and cohesion with the group's style. The Korean version of "" was noted for its high-quality catchiness and delivery, though some found it slower-paced at 7.5/10 compared to the Japanese original. Mixed feedback emerged regarding the repackage's value and execution. While awarded the album a 7/10, appreciating the music video's spectacle (9/10) and the fun but superficial "Welcome to My Playground," it critiqued for overly sing-songy verses and excessive repetition that diluted its impact, suggesting the additions did not fully elevate the originals. In contrast, aggregate scores improved in other outlets, with KPOPREVIEWED giving Regulate an 8.3/10 overall and Cryptic Rock bestowing a perfect 5/5 for its genre-spanning emotional depth across , , and pop.

Commercial performance

Chart performance

The original release of Regular-Irregular debuted at on the Gaon Album Chart in , maintaining the top position for multiple weeks and topping the monthly chart for October 2018. Internationally, the album marked NCT 127's first entry on the , peaking at number 86 with 8,000 equivalent album units in its debut week. It also reached number two on the Billboard World Albums chart. In the , it peaked at number 42 on the Official Album Downloads Chart. In , the Japanese edition debuted at number six on the . The "Regular" peaked at number two on the . The repackage Regulate, released in November 2018, debuted at number two on the Gaon Album Chart in its first week and number five on the monthly chart for November. It peaked at number nine on the World Albums chart. The "" became the group's first number-one hit on the chart, selling 2,000 downloads in its debut week and accumulating 2.1 million U.S. streams.

Sales and certifications

The original Regular-Irregular album sold 292,341 copies in by the end of 2018, securing the #17 position on the Gaon Album Chart year-end ranking. Cumulative physical sales reached 370,616 copies as of July 2022. It earned a from the Korea Music Content Association (KMCA) for shipments surpassing 250,000 units. In the United States, the album sold 8,000 units in its debut week, with total units over 15,000 as of late 2018, though it remains uncertified by the RIAA. The repackage Regulate, released in late 2018, sold 157,809 copies that year. It received a certification from KMCA on November 10, 2022, after shipments exceeded 250,000 units. In Japan, Regulate recorded 62,852 physical sales via charts, falling short of RIAJ status (100,000 units). The lead single "Regular" achieved strong digital performance in Korea, with over 36 million streams on Melon as of mid-2021. It also earned notable downloads internationally, debuting at #2 on Billboard's World Digital Song Sales chart with 3,000 units in its first week.

Track listings

Regular-Irregular

No.TitleWriter(s)Producer(s)Length
1."City 127" (지금 우리; Jigeum Uri)JQKenzie3:19
2."Regular" (Korean version)Taeyong, Mark, Moon Hee-yeon, Coogie, The StereotypesThe Stereotypes3:37
3."Replay" (PM 01:27)Bang Hye-hyun, LDN NoiseLDN Noise3:39
4."Knock On" (노크해; Nokehae)Kim Min-ji, Hong Su-ji, DeCapo, MZMCDeCapo Music Group, MZMC3:25
5."No Longer" (나의 모든 순간; Naui Modeun Sungan)Hwang HyunSimon Petrén4:57
6."Interlude: Regular to Irregular"0:10
7."My Van" (내 Van; Nae Van)Taeyong, Mark, Kim Dong-hyun, 2502503:18
8."Touch"Hwang Hyun, HitchhikerHitchhiker3:26
9."Run Back 2 U"Kang Eun-jeong, Hwang Yu-bin, Double DragonDouble Dragon3:25
10."Fly Away With Me"Dillon Pace, Mike Daley3:23
Total length:32:39

Regulate

No.TitleWriter(s)Producer(s)Length
1."City 127" (지금 우리; Jigeum Uri)JQKenzie3:19
2."Regular" (Korean version)Taeyong, Mark, Moon Hee-yeon, Coogie, The StereotypesThe Stereotypes3:38
3."Replay" (PM 01:27)Bang Hye-hyun, LDN NoiseLDN Noise3:40
4."Welcome to My Playground"Kenzie, Jonghwan, LindgrenKenzie3:59
5."Knock On" (노크해; Nokehae)Kim Min-ji, Hong Su-ji, DeCapo, MZMCDeCapo Music Group, MZMC3:26
6."No Longer" (나의 모든 순간; Naui Modeun Sungan)Hwang HyunSimon Petrén4:58
7."Interlude: Regular to Irregular"0:10
8."My Van" (내 Van; Nae Van)Taeyong, Mark, Kim Dong-hyun, 2502503:18
9."Touch"Hwang Hyun, HitchhikerHitchhiker3:27
10."Come Back"Mike Daley3:21
11."Fly Away With Me"Dillon Pace, Mike Daley3:23
12."Chain" (Korean version)Taeyong, Mark, KenzieKenzie3:34
13."Regular" (English version)The StereotypesThe Stereotypes3:09
14."Simon Says"250, Kim Dong-hyun2503:22
Total length:51:01

Credits and personnel

Regular-Irregular

The production of NCT 127's debut studio album was overseen by Co., Ltd. as executive producer, with serving as overall producer. A team of A&R personnel from handled artist planning and development, including Shin Pyeong-hwa, Yoon Hee-jun, and Jo Yu-eun, alongside direction and coordination for SM USA by Victor Portillo and Janie Yoo. The album features lead and background vocals from all nine members of : Taeyong, Taeil, , Yuta, Doyoung, Jaehyun, Winwin, , and , with parts distributed across the track listing. For instance, in "No Longer," Jaehyun performs the bridge, while verses are shared among Jaehyun and . Additional background vocals were provided by session artists such as Andrew (on ""), Micah Powell, Wilbart "Vedo" McCoy III, Varren Wade, Seo Mi-rae, Doyoung, J. Roston, Onestar (on multiple tracks), Winwin, Yuta, , , Taeyong, , Jaehyun, Taeil, Hwang Sung-je, and Megan Bowen (track-specific). Vocal direction was managed by GDLO and Deez (on several tracks), Andrew (on ""), (on "Run Back 2 U"), and Chu Dae-kwan, with rap direction by 250 and Kim Dong-hyun (on "Vanishing Night"). Songwriting credits included contributions from NCT 127 members on three tracks: Taeyong and co-wrote lyrics for "Regular" alongside Moon Hee-yeon and , while other tracks featured Korean lyricists such as JQ (on "City 127"), Bang Hye-hyun (on "Replay"), and Hwang Hyun (on "Touch"). Production and arrangement were handled by a diverse group of international and domestic collaborators, including (on "Regular"), LDN Noise (producer and arranger on "Replay"), DeCapo Music Group and MZMC (on "Knock On"), Simon Petrén (on "Fly Away With Me"), Hitchhiker (on "Touch" and guitars throughout), (on "Vanishing Night"), Mike Daley (on multiple tracks), Dillon Pace (on "Fly Away With Me"), and (on "Run Back 2 U"). Recording took place primarily at , with engineers including Lee Min-gyu, Lee Ji-hong, , and assistants such as , Hong Soo-yeon, Kang Jae-gu, Lee Chan-mi, and Shin Dae-seop. Digital editing was contributed by Seo Mi-rae, GDLO, Juan "Jay P" Mendez, Min Sung-soo, Hong Sung-jun, and Jang Woo-young (track-specific). Mixing was performed by Jeong Eui-seok, Kim Cheol-soon, Nam Koong-jin, Kim Han-gu, and Koo Jong-pil at various SM facilities.

Regulate

The production of the Regulate repackage album was overseen by Co., Ltd. as , with serving as overall . A&R and management roles were handled similarly to the original album, including Shin Pyeong-hwa, Yoon Hee-jun, and Jo Yu-eun. The repackage features lead and background vocals from all nine members of : Taeyong, Taeil, , Yuta, Doyoung, Jaehyun, Winwin, , and , with parts distributed across tracks, including the new additions. Additional background vocals were provided by session artists such as those listed for the original album, with track-specific contributions on new songs. For the new tracks, songwriting and production credits include:
  • "Simon Says": Writers JQ, DADA, Tommy $trate, Dsign Music, Bobii Lewis, and ; producers Choi Jin-seok, Ronny Svendsen, Anne Judith Stokke Wik, Bobii Lewis, and . Vocal direction by GDLO; mixing by Jeong Eui-seok.
  • "Touch": Reuse of original production by Hitchhiker, with lyrics by Hwang Hyun.
  • "Chain (Korean Ver.)": Writers 250, Andreas Öberg, Bang Hye-hyun, Bobii Lewis, Bong Eun-young; producer 250.
Recording for new tracks occurred at , with engineers including Lee Ji-hong and , and assistants such as . Digital editing by GDLO and Seo Mi-rae; mixing by Kim Cheol-soon and Koo Jong-pil at SM facilities.

Legacy and accolades

Cultural impact

The release of Regular-Irregular marked a pivotal moment in establishing NCT 127's "irregular" identity within the broader NCT project, emphasizing themes of reality versus fantasy that differentiated the subunit from others in Entertainment's multi-unit system. This conceptual framework, blending urban and dreamlike elements, inspired fan engagement through interpretations of the NCT universe, fostering discussions on subunit dynamics and potential expansions. By showcasing a 10-member lineup with experimental and R&B influences, the album reinforced NCT 127's role in popularizing the rotational multi-unit structure, which allowed for localized and thematic versatility across NCT's subunits. The album's promotion, including the title track "Regular," sparked widespread dance challenges on social media platforms, contributing to NCT 127's interactive fan culture post-2018. Its urban aesthetics, featuring layered and styling, influenced K-pop fashion trends, positioning the group as style innovators in editorials and performances. As of November 2025, Regular-Irregular has amassed over 266 million global streams on , underscoring its enduring appeal and role in elevating NCT's international profile. Long-term, the album's success, including its debut at No. 86 on the , laid the groundwork for NCT 127's U.S. and subsequent expansions. The repackaged version, Regulate, featuring "," extended this momentum with performances in American media, such as backstage appearances on local broadcasts, further embedding the group in global entertainment narratives.

Awards and nominations

At the , NCT 127 received a for Best Male Group in recognition of Regular-Irregular and its promotion. The album earned a for the Disc Daesang at the in 2019, highlighting its strong physical sales performance, though the daesang ultimately went to BTS's Love Yourself: Answer. NCT 127 won the Disc Bonsang in the Album Division for Regular-Irregular, acknowledging its commercial success as one of the top-selling physical albums of 2018. At the 8th Gaon Chart Music Awards in , Regular-Irregular contributed to NCT 127's recognition in the physical album categories, with the group securing (Album) for the fourth quarter of 2018; across both the original and Regulate, they amassed a total of five wins in various quarterly and year-end honors.

Release history

Original album

The original album Regular-Irregular by was released digitally on October 12, 2018, worldwide through on platforms including and . This marked the group's first full-length studio album, available for streaming and download immediately upon release at 6 p.m. KST. Physical copies were also issued on October 12, 2018, in by in CD , featuring two main versions: and Irregular, each with distinct artwork and inclusions such as a , booklet, and random photocard. The Korean edition carried the catalog number SMK 1033. availability followed shortly after, with imports distributed globally, enabling the album to debut at number 86 on the US Billboard 200 chart the following week. Physical releases were primarily through Korean retailers and online exporters, without dedicated region-specific variants under labels like Capitol or Avex at the time of launch. The album was offered exclusively in CD format for its original 2018 rollout, with no limited cassette editions or vinyl pressings produced contemporaneously; later reissues in 2021 included updated member-specific covers but retained the CD medium. This physical presentation emphasized collectible elements tailored to the market, aligning with the promotional timeline that began with teaser images and the "Regular" on October 9.

Regulate

The Regulate repackage of NCT 127's debut studio album was first made available digitally worldwide on , 2018, incorporating the original tracks from Regular-Irregular alongside three new songs, including the lead single "," to refresh streaming availability and promote expanded content. This digital rollout occurred through major platforms under S.M. Entertainment, marking an immediate global update to the album's presence following its precursor release two months prior. Physical editions followed shortly after, launching in on November 27, 2018, exclusively via S.M. Entertainment with catalog number SMK 1043 across multiple member-specific variants. International physical distribution, handled by partners such as Alliance Entertainment in the United States and other partners elsewhere, aligned with the Korean physical debut on the same date, ensuring synchronized availability in key markets like and ; a distribution deal with was signed in 2019. The physical formats emphasized collector appeal, featuring standard CD editions in ten distinct versions—one for each NCT 127 member—each containing a 48-page photobook, a compact disc, one random photocard, and a folded poster available through pre-order benefits. These versions shared a consistent design theme centered on the repackage's bold, regulatory motif but varied in cover imagery to highlight individual members, such as Taeyong or Jaehyun editions. In select international markets, including the U.S., digital downloads and streaming dominated without physical variants initially, though import CDs later became available through retailers like Amazon. A limited full-cover box set, compiling all ten versions, was offered for pre-order in South Korea, bundled with additional photocards and a group poster, catering to dedicated fans seeking comprehensive collectibles without separate merchandise like apparel or accessories. Catalog designations for Regulate included SMK 1043 for the primary Korean physical release, reflecting S.M. Entertainment's standard numbering for repackages. This structured rollout prioritized accessibility, with digital updates ensuring seamless integration into existing playlists while physical editions provided tangible expansions unique to the repackage era.