- George Hadjigeorgiou’s personal health scare taught him that even CEOs need to challenge conventional wisdom, leading him to start Zoe.
- As a founder, George took the unconventional route—prioritizing rigorous scientific research over speed to market, proving that long-term trust outweighs short-term gains.
- The success of Zoe’s COVID-tracking app showed George that acting quickly with purpose, even in uncertainty, can create massive impact.
- George believes the best go-to-market strategies come from deeply understanding what people actually want.
- His biggest lesson for entrepreneurs: Take action relentlessly—clarity comes from doing, not just planning.
In this live podcast with Kyriakos the CEO of Terra, George Hadjigeorgiou shares his journey in leveraging a personal health wake-up call to launch Zoe, building the world’s largest nutrition study before bringing a product to market. George tells stories about key CEO lessons, and an insightful Q&A on overcoming fear, go-to-market strategies, and building science-driven startups.
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How a Personal Health Wake-Up Call Led to Founding Zoe
Kyriakos: Let’s go to the beginning. Can you walk us through the founding story of Zoe?
George: Zoe was officially founded on August 7, 2017. I had the idea about a year earlier but I just didn’t know it. After selling both HouseTrip and E-Food, for the first time in my life I decided to take a sabbatical to decompress from the challenges of entrepreneurship and think about what to do next. During the first week of my sabbatical, I took a trip to Crete with a friend. We started talking about food and nutrition, which became our main topic of discussion for five days.
Part of the reason for this discussion was that I had recently done a blood test and discovered I had high cholesterol. I was what they call "TOFI"—thin on the outside, fat on the inside. I visited the lipid clinic at Chelsea and Westminster Hospital, where the doctor gave me a leaflet from the British Heart Foundation advising me not to eat eggs.
At that moment, I vividly remembered my grandmother in our kitchen in Greece telling me not to eat more than two eggs because they were bad for cholesterol. That advice, unchanged for 40 years, didn’t sit right. Researching further, I found it was based on limited studies. One of the most influential studies was the Ancel Keys study from 1972, which examined only 12 men—just half the population. Six of them already had high cholesterol. The study had them eat four eggs a day for four weeks but didn’t control for what else they ate or drank. I thought, "That doesn’t sound right." A poorly designed study with only 12 participants became the basis for worldwide dietary advice.
During our trip, my friend and I discussed why nutrition research relied on such small, outdated studies when we could use vast amounts of data and AI to provide personalized dietary advice. That was the genesis of the idea. We realized that we both had the same problem—uncertainty about what we should eat. We saw the opportunity to use big data and machine learning to provide personalized nutrition guidance, making dietary advice more data-driven and modern.
Kyriakos: My problem, George, is that with your solution, you went against conventional business advice, which is to launch early and get a product to market. Instead, you created the largest nutrition study in the world. How did that happen?
George: First of all, it’s not clear yet whether we did the right or wrong thing, so I want to start with that disclaimer. The reason we took that approach, rather than launching a product immediately, was to collect the largest dataset in the world in the most scientifically advanced way. Our goal was to provide the best insights and advice possible.
We didn’t make this decision for purely business reasons—it mattered to us personally. My co-founders, Tim Spector (60 years old), Jonathan (40 years old), and I (42 years old) had already experienced success, so we wanted to build something truly meaningful and scientifically robust. Our past success also allowed us to raise the funds needed for this approach. Plus, we believed science would become increasingly important in a world of diet fads. While we couldn’t predict if it would matter to everyone, we knew it would matter to people like us—and that audience was growing.
I vividly remember us squatting in a conference room at a VC firm in Golden Square before officially starting the company. We outlined two options on a whiteboard: launch a massive clinical study—which became the largest of its kind with 300,000 participants—or release a product first, like Levels later did. Though I had the idea for Levels long before they launched, but we decided to take the big-data approach and do it the hard way, believing it was the right way for us.
Kyriakos: You mentioned Tim Spector, your third co-founder. How did you convince a scientist to join you?
George: The TLDR is the hustle and money. Right After our trip to Crete, I was discussing nutrition out of curiosity when someone recommended The Diet Myth by Tim Spector. The book fascinated me—it introduced the impact of gut bacteria on health and mood.
A mutual connection, who later became our first investor, introduced us to Tim. He was warm but skeptical, having seen many entrepreneurs come and go. He told us if we could secure funding, he’d take us seriously. So that’s what we did. A few months later, we secured funding, which proved our credibility, and Tim joined us. So if you can hustle to get an introduction to somebody like that it always helps.
From Research to Recognition—How Data and a Pandemic Shaped the Launch of Zoe
Kyriakos: Many companies claim they need a lot of data to build their business, but most don’t do it correctly. How did you approach this, and what was your first product?
George: When we raised our first round of funding—about $6 million—it was based on just eight slides and 50 words. We followed through on exactly what we outlined in those slides, which is also untypical.
Our approach was to use clinical studies as an early, complex version of our product. It was time-consuming and challenging, but we wanted to ensure the highest level of scientific accuracy before launching to consumers. The plan was to gradually simplify the studies until we arrived at a a home test kit delivering personalized insights. Users could scan food items for scores and recommendations, later expanding to personalized probiotics.
Our first study involved 1,000 participants—700 of them twins—undergoing intensive hospital testing, followed by two weeks of glucose monitoring, blood tests, and food logging. A year later, participants received a PDF report with scores and insights about the best foods for them. This was our first "product"—essentially a research-driven version of what would become the consumer offering.
Kyriakos: So your go-to-market strategy was actually through the study?
George: Yes, we recruited participants for the study as a way to understand what messaging resonated from a marketing perspective. Then they do this really intense kind of testing like even at the hospital and then we'll give them results in a very clanky way as part of that we actually getting the feedback. For our second study, we moved everything to the home—still 14 days of monitoring but no hospital visits. This streamlined testing, refined our algorithms, and prepared us for launch.
Kyriakos: Was that around the time COVID hit?
George: Yes. Just before launching our commercial product in the spring of 2020, COVID happened. You remember what it was like. It was a chaotic time. People were scared, governments didn’t have clear information, and nobody knew how serious the virus was. My co-founder Tim had an idea—one of the ten ideas he comes up with daily—and he suggested we do something to help. We decided to leverage our data-driven approach to launch an app that tracked COVID symptoms and their progression. In just five days, we built and launched the app. To our surprise, it went viral—5 million UK users made it the largest community science project on COVID. A key discovery was anosmia (loss of smell and taste) as a leading symptom. Within days, we published a study in Nature Medicine, leading governments to recognize it officially.
I'm sharing the story only to say that sometimes you say, “You know I'm going to do something, I have no idea whether it's going to work. But I have a good feeling about why I want to do it.” That's the insight I want to pass. Our motivation was simply to help people where it matters, and it turned out to be one of the most wonderful things we’ve ever done in our lives.
Kyriakos: Did the success of the COVID app help when launching your commercial product?
George: Absolutely. Again you're doing something you don't know whether it's going to basically play out and suddenly luck happens. The COVID app made Zoe a household name in the UK. When we transitioned to our core nutrition product, we carried that trust forward. At the end of the day the same underpinning was there—real science, powered by people, for people. We reinforced this through our podcast and content, which built credibility and awareness.
Strategic Growth and Smart Fundraising
Kyriakos: At what point did you decide when to expand into new product lines? I recently saw your gut health supplements, which are quite different from typical powders.
George: From the very beginning, our vision included supplements for gut health based on our data and insights. As we progressed, it became even clearer why this was a valuable area to focus on. Following dietary advice is tough—eating well sounds simple, but most struggle long-term. Zoe aims to change the logos of control from doctors to individuals, empowering them with personalized insights, helping them sustain healthier habits from four to ten months. But the reality is, even with the best tools, 90% still revert to old patterns. That’s where our supplements help—an easy, everyday solution to support long-term health. The simpler the habit, the more likely people stick with it.
Kyriakos: You make fundraising sound easy. Can you give us some advice?
George: Fundraising becomes easier once you’ve built companies before. That experience plays a big role. The most important advice I can give is to put yourself in the investor’s shoes. Most investors won’t respond to cold emails, so you have to assume that’s a dead end. Instead, figure out who in their network can give you a strong introduction. Find your way in terms of getting a warm strong introduction from someone who can represent you and say “Hey take that call because this person, I really believe in them and they want to actually really build something.”
Another key point is aligning incentives. I would argue that 99% of businesses are not the right businesses to go and raise venture capital. My uncle built a successful pasta business in Greece over 45 years without VC, relying on bank loans and steady growth. Entrepreneurs should be brutally honest about whether VC funding is the right fit for them. If not, don’t waste time chasing it. If unsure, start with friends and family funding and reassess. The goal is to find the right capital for your business and align incentives with investors.
Overcoming Fear, Taking Action, and Finding Your Path
Kyriakos: If you could give startup advice to your younger self, what would it be?
George: At the end of the day, one of the most unspoken thing about is fear and the relationship with fear. Almost every person experiences fear daily. It can be paralyzing. Fear has two paths: one leads to paralysis and inaction, while the other leads to action. The whole bet is how to be in the action mode and not the inaction mode. Eliminating fear is impossible—everyone has it. If I could give my younger self one piece of advice, it would be to have a conversation with fear. Say, “Hey fear, I hear you, I see you. We're together. Now just go and sit in the back and let me drive.”
Kyriakos: What advice would you give to people trying to figure out what to work on?
George: I don’t believe in telling people what they should work on. My biggest learning is, “hit the ball a lot”. Action produces information. People say, “Find what you’re best at,” but I have no clue what I’m good at and why do I need to compare? But by hitting the ball a lot you at least understand what you like, you learn what excites you and whether you want to spend all your time on it. And that's a valuable sign right in terms of basically what to do.
This idea—of constantly hitting the ball—is very much antithetical to what we’ve been taught in life. We’re taught you need to be successful otherwise you’ll be a failure. But if you look at highly successful people, they’ve “failed” way more times than they’ve succeeded. Nobody remembers their failures, only their wins. So just take action. Every step teaches you something, and the more you act, the clearer your path becomes.
Live Q&A: The Future of Zoe, Startup Challenges, and Go-to-Market Strategies
Audience member: I’m a big fan of Zoe. I’ve been doing my own nutritional studies, though not clinically. What does the future look like for Zoe? For example, I see you’re wearing an Oura ring—do you see integration with wearables?
George: The future of Zoe moves along two key axes: how to make our advice and solutions simpler and more accessible to people.
Let me give an example—not something we’re necessarily working on, but an idea of where the future could look like. I was recently trying out the Meta smart glasses. I believe that one of the dominant future interfaces will be vision, voice, and sound.
Imagine wearing these glasses that can see everything you eat. It will happen. If your eyes can see what you put in your mouth, your glasses can too. Instead of manually logging food or scanning menus, the glasses could tell you in real-time, “Hey George, today hasn’t been great—you’re already at 2,000 calories, and your nutrition score is low. Maybe take it easy for the rest of the day, don’t eat for the next three hours before you go to bed, and focus on better choices tomorrow.”
When we founded Zoe—Zoe means “life” in Greek—the vision was to create a personal AI nutritionist in your pocket. That is where I think the future is going on that dimension is basically through this new dominant interface like voice and vision things are going start becoming more and more effortless.
Audience member: You had the advantage of prior success, which made it easier to raise funding for a science-based product. For those of us without that privilege, science comes with regulatory hurdles that can bury a product before it even launches. What advice would you give to startups trying to bootstrap—especially when feasibility studies are required to prove effectiveness and safety?
George: It’s difficult to give a one-size-fits-all answer, but there are always different ways to approach this challenge.
If you can’t raise money to fund the scientific studies required to prove efficacy or safety, ask yourself: “What do I need to prove to an investor?” Break it down into smaller steps that build credibility and reduce risk for potential backers.
One approach is testing the market with a dummy product. Before even launching, you can run ads or set up a landing page to see if people are willing to pay for your solution. This validates demand before you invest heavily.
If that’s not enough to secure funding for studies, consider running smaller tests or simulations. Use preliminary data to predict your product’s effectiveness. Try to put it in chunks that can give an investor some comfort that's investing the whole thing is worthwhile because it'll be returned or is de-risked. Or I would chunk it into smaller phases to invest in one inflection point to the next. At the core of it, you need to show that people will actually buy your product and that you have a path to proving its safety and efficacy.
Audience member: We’ve talked about product, hiring, and funding, but what about go-to-market and sales? How should a startup figure out its go-to-market strategy?
George: Go-to-market strategy depends on the type of startup. Is it consumer-focused or B2B? That changes the approach.
For me, the best way to figure out any go-to-market strategy is to talk to customers. Direct conversations help find the right kind of pitch, positioning, and competitive differentiation. You also understand what truly resonates with them.
One framework I love is the Jobs to Be Done framework, developed by Bob Moesta and Clayton Christensen. It shifts the focus from selling a product to understanding the progress customers are trying to make in their lives. Sales isn’t about pushing a product; it’s about helping customers solve a problem or improve their situation. That’s why they say “demand sides sales,” not “supply sides sales”. One way to figure that out is by conducting demand-side sales interviews—sitting down with potential customers and mapping out their journey over the past few years. What triggered them to seek a solution? What barriers did they face? What finally made them buy? By mapping this process, you identify the best way to position your product and what it takes to convince customers to adopt it.