Embryo has completed its third acquisition in less than a year following a deal for creative and digital agency Serotonin.
The deal follows acquisitions of Making You Content in April 2025 and Novaro in November 2025.
Serotonin was founded in 2019 by Dom Carter and Clair Heaviside and is best known for its work with major eCommerce players such as ASSOS of Switzerland, New & Lingwood, as well as national property developers including Legal & General and Grainger plc.
Embryo鈥檚 CEO Ross Green said: 鈥淓mbryo is renowned for its strategic thinking, organic and performance capabilities.
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鈥淲e believe exceptional marketing results come when strategy, creativity, and execution work seamlessly together.
鈥淭heir team has built an outstanding reputation for performance marketing, backed by a strong creative offering and media-buying expertise.
鈥淏y bringing Serotonin into Embryo, we鈥檙e strengthening our ability to deliver even greater impact for our clients, combining Embryo鈥檚 strategy-led approach with Serotonin鈥檚 creative excellence, media capabilities and strong client base across EMEA.
鈥淢ost importantly, this acquisition is about people. Dom and Clair will be joining the Embryo board, and we welcome the talented Serotonin team, who have built something special over the past six years, and we鈥檙e incredibly excited to welcome them to Embryo as we enter this next chapter together.
鈥淲e鈥檙e also looking forward to welcoming Serotonin鈥檚 clients into the business and to meeting them in the coming weeks.
鈥淏uilding strong relationships has always been at the heart of what we do, and we鈥檙e excited about the opportunity to support their continued growth.
鈥淢anchester continues to be one of the most exciting and ambitious digital hubs in the UK, and this move reinforces our commitment to building one of the UK’s leading performance-driven agencies.”
New roles for founders
As part of the transition, Heaviside will become chief creative officer and Carter will take on the role of chief strategy officer.
Carter said: 鈥淔or six years, we’ve been building Serotonin with one goal in mind: to do work that truly matters, with people who care as deeply about it as we do.
鈥淎long the way, one agency kept standing out. In pitches, in conversations, in the way they carry themselves in the market – Embryo always felt like the benchmark. The agency I measured ourselves against.
鈥淪o when the opportunity came to bring Serotonin into the Embryo family, it felt like the natural next chapter we’ve been building toward.
鈥淭ogether, we’re now one of the largest independent agencies in Manchester, combining performance media, creative, SEO, brand and strategy under one roof.鈥�
Clair Heaviside said: 鈥淎fter six-and-a-half years building Serotonin alongside Dom Carter. I can share the next chapter of our story.
鈥淪erotonin has been acquired by Embryo, an agency I have admired for a long time.
鈥淔rom the moment we started talking with Ross Green about the acquisition, it felt right. The same ambitions. The same values. The same belief that great work should actually move things forward.
鈥淲hat started in the Northern Quarter as a two-person agency grew into something I’m genuinely proud of, a team that combined strategic thinking with creative work that didn’t just look good, but made an impact.
鈥淚n this next chapter, I’ll be stepping into the role of chief creative officer at Embryo, focused on building out the creative and brand offering. Dom will take on chief strategy officer, shaping strategic direction and driving growth.
鈥淭ogether, we’re joining a team that has the scale, the ambition, and the culture to do what we’ve always wanted – offer clients something truly complete, from positioning and storytelling through to digital performance.
鈥淚t feels like the start of something truly exciting. Here’s to the future, and everything we can build together. Let’s go.鈥�
Embryo was founded in 2014 by Ross Green alongside James Welch, who tragically died last year.