Serotonin

Serotonin is the performance marketing agency for brands that want to move faster and grow smarter. Founded by Dom Carter and Clair Heaviside, we bring over a decade of experience scaling brands across the UK, Europe and the US. We skip the jargon, the fluff, and the vanity metrics. What we deliver is clarity, pace and a commercial mindset—from forecasting and strategy through to media buying, performance creative and CRO. If it drives growth, we’re on it. Our team pairs deep technical expertise across Meta, Google, TikTok and Amazon with creative that cuts through. We understand the full customer journey just as well as we understand a click-through rate—and we know how to turn performance data into practical direction. We’ve taken brands from £5k to £100k/month, launched fitness giants into new markets, and helped legacy names modernise how they do digital. Whether you’re early-stage or revenue-stuck, Serotonin brings the momentum. We work best with founders, CMOs and marketers who value straight-talking partnership and results that actually show up in your bottom line. Less time spent talking, more time scaling. This isn’t an agency that adds noise. It’s one that brings signal. Serotonin: the growth partner for ambitious brands.