UK start-up Echo Pharmacy has appointed Love Sugar Science for media planning and buying.
Echo operates an app that helps patients manage their repeat prescriptions from the NHS.
Two healthcare professionals, who have long-standing medical prescriptions themselves, founded Echo in 2015.
About 40% of prescriptions are repeat ones and Echo, which is based in London, claims to have already grown to become the second-biggest dispensary in England.
Chemists chain LloydsPharmacy, which is owned by US group McKesson, bought Echo in June as the healthcare sector becomes increasingly digitised.
Manchester-based Love Sugar Science launched in March as "a better sort of media and communications agency" that reunites the two disciplines and puts creativity "at the heart of media".
It is backed by Goodstuff Communications, which has a minority equity stake in the business.
Bradley Fehler, head of growth at Echo, said: "This is the start of an exciting new phase for Echo and we are delighted to be working with the Love Sugar Science team.
"We remain an entrepreneurial business and needed a partner who could provide the mix of creative and effective thinking vital to help us unlock the growth opportunities in the market."
Jessica Scott, a co-founder of Love Sugar Science, said: "We are really excited to be working with Echo. The team gave us an inspiring vision of what the future looked like for their business, as well as a clear view on the role that communications will play for them in realising this.
"Echo demonstrated their commitment to a more creative approach to communications and we can’t wait to support them as they deliver on this next phase of their business growth."
M&C Saatchi Accelerator, a spin-off from M&C Saatchi that specialises in "growth" companies, is working on advertising for Echo.
Love Sugar Science already has several clients, including Manchester-based online fashion retailer I Saw It First, a commercial partner on this year’s series of Love Island on ITV2.
Scott said the fact that Echo is based in London and Love Sugar Science is in Manchester was not significant.
"We’re not just going after Manchester clients," she said. "We hope a lot of our clients will come from all round the country."