Short answer: yes, you can order a blood test for a single health marker, but it may not be worth it as it is not informative or reliable enough. As a self-payer in Germany or many other countries in Europe you can test one biomarker without a referral. But a single result only helps if you also know whether it is healthy and what to do about it.
But please be aware, a single-marker blood test measures just one biomarker on its own, rather than a fixed bundle of them. If you only want to know your vitamin D, your iron stores, or your thyroid, you do not need a full check-up to find out. In Germany, self-payers can order that one test directly, no referral required.
That freedom is why walk-in direct labs have grown popular. You pick a test, pay for it, get your blood drawn, and often see the result the same day. It is simple and it works. The catch is what happens after that result lands.
There are three common routes. Your GP can order a test, though usually only when there is a medical reason and often not as a self-pay convenience. A walk-in direct lab, such as one of the Sonic Healthcare or Bioscientia sites, lets you buy individual tests on the spot as a self-payer. And online testing services like Aniva let you order the test from home, then send you to a partner location for the draw.
All three can measure a single marker. Where they differ is in what you receive back, and whether you can build on it later.
A direct lab is built for speed. You get a clean measurement against the standard reference range, the wide band that covers most of the population. For a yes or no question, that is often enough. If you just want to confirm your vitamin D is not on the floor, a single test answers it.
The limits show up when the result is not a clear yes or no. A result can sit inside the reference range and still be far from where you feel your best, because a reference range describes the average population, not the level linked to functioning well. A lone value also has no memory: next year's test starts from scratch, in a different portal, with nothing to compare against.
One health marker, measured on its own, tells you its current value. It does not tell you whether that value is healthy for you, or what to do next.
This is the gap Aniva was built to close, without taking away the thing people like about direct labs: ordering exactly what you want.
Most preventive-health startups sell boxed panels. You buy the box, you get the markers in the box, and that is that. It keeps their operations simple, but it means you often pay for markers you did not want, or cannot add the one you did.
Aniva took a different approach. Your membership includes the 100+ marker Core panel, and during onboarding you can add any individual markers on top. You can also re-test a single marker on its own later, without repeating the whole panel. Among direct-to-consumer testing services, that flexibility is still rare.
Both let you test a single marker. The difference is everything that surrounds the result.
To make the interpretation concrete, take vitamin D. The Robert Koch Institute reports that a large share of adults in Germany do not reach the vitamin D level it uses as a benchmark, especially in winter. A direct lab will tell you your vitamin D value. Aniva shows you the same value, marks where it sits against the optimal range, and tells you what, if anything, to change, then checks it again next year so you can see whether it moved.
If you truly want a single result, fast, and nothing more, a walk-in direct lab does the job well. There is no shame in a single quick test. But if you think you will test more than once, if a result inside the normal range still leaves you wondering, or if you would rather see your markers in context and tracked over time, a membership that includes the panel and lets you add single markers tends to give you more for less over the year.
The honest answer is that it depends on how much you want to do with the result. A direct lab hands you a fact. Aniva hands you a fact, a benchmark, and a next step.
