“For me the highlight with Vivid is that I don’t have to read out my PDFs myself, no matter how badly they’re scanned.”
Dorian Wetter, Co-Founder and Managing Director, Endon Blutbild
Tell someone their bilirubin is slightly elevated and you have handed them a number. Tell an athlete they may be training ten percent too much, that their protein is not enough and that their sleep is less restorative than it could be, and you have handed them something they can change on Monday morning. The distance between those two sentences is the business Karl Stickler and Dorian Wetter built.
The two co-founders launched Endon Blutbild in March 2025 and run it from Frankfurt am Main under the legal entity 20plus Health UG. The customer books a laboratory appointment, Endon briefs them on how to prepare, the lab sends the marker results back, and then comes the part the market was missing: the company converts those markers into the three areas it works in — fitness, nutrition and recovery — and talks them through with the athlete in a live call. The company’s business account is with Vivid, which Wetter found through an AI search.
The Deepest Data Source There Is
Most self-measurement today happens at the surface. Step counts, heart rate, sleep, weight. Stickler’s argument for blood is about depth.
“Most of the trackers we have at the moment — fitness trackers, scales, weight — measure at the surface, on the outside of the body,” he says. “Blood is the deepest data source. If you could only have one piece of information about a person, blood is by far the deepest data source, one that can give us deep insight into fitness, nutrition and recovery.”
“No other data source shows you not just what I put in — a number of steps — but what actually reaches the body.”
Karl Stickler, Co-Founder, Endon Blutbild
The process is unglamorous. The customer books a slot at the lab, follows Endon’s preparation notes on what to do and what to avoid beforehand, and has blood drawn. The lab analyses it, Endon receives the values, and the translation begins. Raw markers become concrete statements the athlete can act on, and those statements are discussed directly rather than delivered as a generated report. Roughly three months later, the company tests again to see whether the changes actually moved anything.
What Endon does not do is medicine. “Endon focuses on lifestyle and performance optimisation,” Stickler says — fitness, nutrition and recovery, three areas where most of their users still have something left to gain. “We leave the whole medical topic to doctors, who are simply very well trained, have very strong expertise and can cover all these subject areas very well.”
Why Athletes First
Endon began in one narrow slice of the health market, and Wetter’s reasoning for that is partly technical: endurance athletes are a relatively homogeneous group in terms of their blood profile, which means the company can say something precise about them rather than something vague about everyone.
The other half of the reasoning is commercial.
“We didn’t want to sell the blood test for everyone that doesn’t really fit anyone and fits everyone only a little. We wanted to do a continuous rollout through the market, beginning with endurance sport.”
Dorian Wetter, Co-Founder and Managing Director, Endon Blutbild
From there, he says, the plan is to move to individual target groups the company can genuinely help — “not just a little”. Other providers in the market claim to serve everyone, in his view, without understanding any single group well enough to be useful to it.
Stickler adds the demand-side argument. Athletes, he says, are perhaps more interested than the general population in squeezing out the last few percent — someone putting in at least ten hours of training a week, often alongside a normal job. “If you can then tell them, hey, you have the chance to squeeze out a few more percentage points with the same training, that’s something where a lot of athletes simply say: that’s exactly what I need.” The founders also have the feeling, he says, that athletes are more open to new methods when they can see an advantage in them. The broader performance market is attractive long term, but he expects it to require a wider level of proof first.
A Million Things That Should Have Happened Yesterday
Ask Stickler what was hard about building the company and he names two things. The first was starting from zero credibility: building a network, finding experts, becoming known in the market, and proving step by step that this was not a random side project but something with real credibility behind it. The second is simply the daily condition of a young company. “Every day you’re facing a million things that actually should have happened yesterday, and you simply don’t have time to do everything,” he says. “You have to keep thinking about where to prioritise sensibly — what really has to happen, and what can potentially be pushed or come later.”
Wetter describes the same effect on a longer timescale. You look at where you are and where you want to be, estimate two or three days, and it takes a week and a half. However hard and however well prioritised you work, he says, things keep coming up in between.
The other constraint was regulatory. The founders had anticipated a regulated landscape; they had not anticipated how complicated moving through it would be.
“Even though the big goal is to help people, it’s very difficult to do it in a way that is legally okay.”
Dorian Wetter, Co-Founder and Managing Director, Endon Blutbild
They got through it, he says, but it was much harder than they thought.
What AI Takes Over, and What It Doesn’t
Both founders describe automation as having changed how the work gets done. Wetter says the company built its own AI system, under what he calls the necessary and quite high data protection standards, covering everything that is not critical customer-related data. Very many workflows now run almost completely automated, he says — bookkeeping among them. “We can achieve considerably more with fewer people, and the AI takes over precisely the tasks nobody wants to do.”
Stickler describes the same shift on the product side: development work for the website, customer portals and partner interactions, plus code development and the small things — even spell-checking, he notes, is better than most text tools manage. Work that used to be manual effort is now absorbed, which he describes as a fundamental change in how they work.
What has not moved is the expert layer. Endon works with a large network of specialists in sports science, nutrition science and laboratory medicine, and Wetter is blunt about why: when the company puts complex questions from those fields to an AI — something it does test — the answers contain errors. There is also a reason on the demand side.
“Now that all people have this AI access, people long even more for a human being to tell them what’s what, what to do, what matters.”
Dorian Wetter, Co-Founder and Managing Director, Endon Blutbild
That is why the results conversation is a live call rather than a generated report. The company could produce an AI report, Wetter says; it believes it is far more valuable for the customer to speak to a person who can answer directly on the basis of their expertise. Stickler frames the same point as a matter of trust. “I believe a fundamental building block is that we as human beings like interacting with other human beings, and we invest a great deal of trust in that,” he says. That is why Endon works with experts and athletes whose experience is not only theoretical, from books, but who know themselves what it means to see the values, or to live it in training and competition.
Both are cautious about how fast that changes in medicine specifically. Wetter hears from the physicians the company works with about a tension: AI can handle quite a few tasks well, but it is not actually approved for that, so the practitioner is left asking whether they are allowed to use it. He tells the story of a physician with very old, geriatric patients who typically take a whole range of medications with all sorts of possible interactions. You can look interactions up. Enter the symptom picture and the medication list, and the AI does the looking up for you — and you only have to check whether what it says is correct instead of running the entire process yourself. Is it approved for that in the moment? No. Which is precisely his point: medicine is so strongly regulated, he argues, that the field needs sensibly regulated approved solutions, both large ones and ones for many individual fields.
Their Own Best Customers
Both founders test themselves. “I’m one of our most important customers, so to speak,” Wetter says. He tracks the same dimensions on himself that the company tracks for its customers, and wears two trackers — three stressful months and some weekend events, and the values go down. The reverse is just as visible: when he eats well, recovers properly and keeps training load appropriately high but not too high, progress shows up quickly, proven in black and white from his own data.
Stickler tests regularly too, though he admits he does not always run the company’s main test on himself. He experiments — new markers, smaller marker sets over time — to see how things change after heavy loads or across different phases, and to watch first-hand how individual markers react and interact. Asked which values he watches most closely in himself, he answers with the method rather than with a marker.
“With our analysis we usually say the truth isn’t in individual values, but in the correlation of different values.”
Karl Stickler, Co-Founder, Endon Blutbild
A single marker can fluctuate for twenty different reasons, he says. Ten markers together become genuinely meaningful.
What keeps him working on it is partly the people on the other side of the call. Professional athletes and amateurs alike sacrifice a great deal of time and effort to reach their goals, often with a very strong mindset, and he finds it straightforwardly enjoyable to work with people who know how much effort it takes and keep pushing anyway. The other half is the data itself: generating insight from a source that is not yet used the way it could be, and opening up another route to optimisation.
Speed, and Not Reading PDFs
Wetter found Vivid through an AI search. His requirements were specific: not a dusty company but a modern one, plenty of technological support, a simple interface, fast onboarding, a good way of interacting with it. Vivid landed at the top of the results. He looked at it and was convinced fairly quickly.
What he values most is that it is uncomplicated. Two-factor authentication is non-negotiable for him on a business account, but it should run as fast as possible: a code he knows, then the app, a quick tap, Face ID. Logging in is very fast and still secure — if he loses both the code and his phone, he says, that is his own fault.
“What I like about Vivid across the board is the speed, the interfaces, which are very clear — it’s simply easy to understand and very fast to use.”
Dorian Wetter, Co-Founder and Managing Director, Endon Blutbild
Then there is the feature he keeps coming back to. Invoices arrive as PDFs, or as paper that someone has turned into a PDF, and he can drag and drop them straight in; Vivid reads out all the data he needs for the transfer. “That means I’m not sitting there reading, and then possibly entering the IBAN wrong at the end even though I checked it twice,” he says. “That’s a feature that concretely saves me time.”
Beyond that, Endon uses Vivid in a deliberately goal-oriented way — as a classic business account, plus two features. “You quite often get very cool offers for increased interest on the money that’s on the account anyway,” Wetter says. “That’s attractive, and then we can also regularly choose which types of spending we want to get cashback on. And cashback is of course also something very likeable.”
Wetter makes sure the classic CFO tasks get done, alongside the strategic direction of the company; the synthesis of an expert network whose members do not always agree with one another runs through him and his co-founder together. The core of his day he spends at a laptop, either talking to customers or doing everything he can to prepare those conversations and make them better.
Note: This article describes the individual experience of a Vivid customer and is provided for general information only. It is not legal, financial, investment or tax advice, and it is not a guarantee of future results. Investing involves risk, including the possible loss of capital; the value of investments can go up as well as down. Product availability, rates and conditions depend on the selected plan and may change. Information as of September 2026. Please seek advice from a qualified professional for your own situation.
