I Kept Formulating for the Average Customer, the Average Customer Doesn’t Exist
Alastair Jessel is the Founder & CEO of The Postbiotic Company Ltd (AYA BIOME™) and Director of Battersea Park Clinic, London. He writes The Postbiotic Dispatch, an evidence-led newsletter on gut health, longevity, and the science behind postbiotic supplementation.
For the first year of building The Postbiotic Company, I made a mistake that I suspect is close to universal among founders building anything biological, behavioural, or personal: I designed for an average person who, on closer inspection, barely exists. It took two ingredients, one aimed at women, one at men, to make the mistake visible to me. Once I saw it in our own formulations, I started seeing it everywhere else too.
The gap nobody puts on the label
Here’s the biology, briefly, because the business lesson doesn’t work without it. Soy isoflavones are often marketed as broadly beneficial for menopausal symptoms. But the actual active compound your body needs, S-equol, isn’t in soy itself. Specific gut bacteria produce it by converting a soy compound called daidzein into S-equol. Roughly one in five Western women actually carries the bacterial strains needed to make that conversion happen. The other four out of five can eat all the soy they like and simply won’t get the benefit the marketing implies.
We saw the same structural gap on the men’s side. Pomegranate is heavily marketed for mitochondrial and cardiovascular support, based on a compound called Urolithin A. But Urolithin A isn’t in pomegranate either, it’s produced when gut bacteria ferment pomegranate’s ellagitannins, and somewhere around 60% of people don’t produce meaningful amounts of it from the raw fruit or juice at all.
In both cases, an entire supplement category was built around delivering a raw ingredient and hoping the customer’s internal machinery would finish the job. Most of the time, for most people, it doesn’t.
Why the average customer doesn’t exist beyond biology
I want to be careful here, because it would be easy to tell this story as “look how clever our science is” and miss the actual point, which is a product-strategy point, not a formulation one.
The industry standard was to formulate for the median case and let the label imply universal benefit. That’s not fraud, the raw ingredient genuinely does contain the relevant precursor compound, and for the subset of people whose biology cooperates, the product works exactly as described. But it means most buyers are paying for a benefit their own body structurally cannot deliver, and nothing on the packaging tells them that.
This is a pattern I now actively look for in other categories, because I don’t think it’s unique to supplements. Any product built around an “average” input, a software feature designed for the average user’s workflow, a service designed for the average client’s needs, a course designed for the average learner’s pace, risks the same failure mode: it works well for the middle of the distribution and quietly underperforms for everyone else, while the marketing implies universal effectiveness.
What changed once we saw the gap
Once you know the conversion step is the bottleneck, the fix is almost embarrassingly direct: stop asking the customer’s body to do the conversion and do it upstream instead. Deliver the already-converted, bioactive compound directly, produced through a controlled fermentation process, rather than the raw precursor and a hope.
That’s a formulation decision, but it’s also, I think, a useful general question for anyone building a product: where in your value chain are you quietly asking the customer to do something themselves that you could actually do for them, and how much of your addressable market are you losing to people who simply can’t complete that step?
We weren’t rigorous about being explicit here either, in fairness. When we made that same shift for the men’s formulation, we were careful to distinguish between what the underlying compound’s clinical trials had shown, at their studied doses, and what our specific fermented-extract dose could honestly claim. It’s tempting, once you’ve found a genuinely better mechanism, to borrow the evidence more generously than it supports. Resisting that temptation cost us some punchier marketing copy. It’s also the only version of the claim I’d be comfortable defending to a scientist, a regulator, or a sceptical customer, which, in the long run, is the only version worth making.
The question worth taking out of the supplement aisle
If I could hand one question to another founder building almost anything, it would be this: which of your customers are structurally unable to get the benefit you’re describing, not because they’re using the product wrong, but because of something true about them that your product was never built to accommodate?
Most businesses never ask it, because the average customer is easier to design for, market to, and measure. But the average customer is a statistical convenience, not a person who walks through your door. The real ones show up in the gaps, and building for the gaps, once you actually look for them, tends to be where the interesting, defensible work lives.
Read more from Alastair Jessel
Alastair Jessel, Founder, CEO & Director of The Postbiotic Company Ltd
Alastair Jessel is the Founder & CEO of The Postbiotic Company Ltd, the maker of AYA BIOME™, a premium postbiotic supplement range built on clinically studied fermented ingredients. He is also Director of Battersea Park Clinic, an integrative wellness centre in London offering therapies from hyperbaric oxygen to red light and Energy Enhancement Systems. Alastair writes The Postbiotic Dispatch, a Substack newsletter known for its forensic, evidence-led take on the supplement and wellness industry - one that holds his own products to the same scrutiny as everyone else’s. His work sits at the intersection of product development, regulatory compliance, and public education on the emerging science of postbiotics.
