PeptideCompareHome blood testing — what it does and doesn't tell you.
Among our new Blood Testing suppliers you'll find four services that test your blood without a GP visit first: a finger-prick or an upper-arm patch, an envelope back to the lab, and a result in an app within a few days. That's appealing — and partly deserved. But what does the science actually say about routine, broad blood testing when you have no symptoms? We went through all four services to find out what's well supported, and what isn't.
- The labs behind these services are accredited (ISO 15189, DAkkS, UKAS) — the same quality standard used by hospital labs.
- Self-collection with a finger-prick or an upper-arm patch (such as Tasso+) gives results for most biomarkers that agree well with a standard venous draw.
- For broad, routine testing in people without symptoms, the largest review on the topic found no demonstrable effect on illness or death.
- The more markers you test at once, the higher the chance of an ‘abnormal’ result that's pure chance — with 10 tests, that's already about a 40% chance of at least one.
- Tracking trends can be valuable, but it requires understanding your own natural fluctuation — not every change between two measurements is a signal.
What these four services actually offer
Damoi (Germany) uses the Tasso+ system, a needle-free upper-arm patch that collects a small blood sample, and measures 35 markers across four panels — from cholesterol to testosterone. Analysis happens in a German lab accredited to DIN EN ISO 15189. Chirayou uses the same Tasso+ system for a baseline panel of 10 markers (including vitamin D, hsCRP and ApoB), analysed by the Limbach Group, a German DAkkS-accredited lab. Forth (United Kingdom) uses a finger-prick and offers a broad range — from hormones and thyroid to sports performance — analysed in UKAS-accredited labs, partly via NHS lab partners. Homed-IQ (Netherlands) offers over 50 tests via finger-prick or urine, from cholesterol to STI and allergy testing, in an ISO 15189-accredited lab.
All four operate without a GP referral, deliver results within a few working days through their own app or portal, and explicitly state that an external lab performs the analysis — not the company itself.
What's well supported
Two things you can take at face value. First: ISO 15189 is a real, verifiable quality standard — the same one most hospital laboratories must meet. An accredited lab means the measurement method itself has been validated. Second: self-collection with a finger-prick or a patch like Tasso+ is now well studied. A 2025 meta-analysis in Clinical Biochemistry, based on 26 studies, found strong agreement between self-collected capillary blood and a standard venous draw (r = 0.89), and 99% concordance when simply classifying a result as normal or abnormal. Agreement was somewhat weaker for inflammatory markers (r = 0.81) than for markers such as cholesterol or HbA1c. Self-collection does what it needs to do: produce a reliable sample, with less pain than a needle in the vein.
What isn't proven yet
The harder question isn't about the labs, but about whether broad, routine testing itself does anything when you have no symptoms. The largest Cochrane review on this topic analysed 15 trials with over 250,000 participants combined, looking at the effect of general health checks in adults without symptoms. The result: no demonstrable effect on all-cause mortality, cardiovascular mortality or cancer mortality, and no effect on the occurrence of heart disease or stroke. That doesn't mean testing is pointless — it means that routine, untargeted testing of healthy people as a standing habit has no proven benefit on the outcomes that actually matter.
There's also a statistical effect that marketing rarely mentions: the more markers you measure at once, the higher the chance that one of them will fall outside the normal range purely by chance — not because anything is wrong, but because a reference range is, by definition, set to flag 5% of healthy people as ‘abnormal’. That principle was already described in 1980 in The Journal of Family Practice, and the maths is simple: with 10 independent tests, the chance of at least one ‘abnormal’ result in a perfectly healthy person is already around 40%. With a 35-marker panel like Damoi's, that chance climbs further still. This isn't a criticism of these specific labs — it's a mathematical fact that applies to any broad panel, in a hospital just as much as at home.
Finally: the idea that testing more often lets you spot ‘trends’ before something goes wrong sounds logical, but is more subtle than it appears. Research on biological variation shows that most blood values in an individual are relatively stable over time around their own personal baseline, while that baseline can differ considerably between people. That means your own history can indeed be more informative than a population reference range — but only if you account for the normal fluctuation every value naturally has. Without that context, a difference between two measurements is just as likely to be noise as signal.
How to use this sensibly
Choose deliberately: a handful of markers tied to a specific question or risk factor often tells you more than the biggest panel. Treat a single abnormal value as a reason to retest or discuss it, not as a diagnosis — especially for a marker you've only measured once. Keep your results so you can see your own line over time, not just a single snapshot. And keep treating these services as a complement to, not a replacement for, your GP — especially the moment a result falls outside the line.
While going through this and comparable services, we repeatedly saw the promise that routine broad testing catches problems early. That sounds logical, but the largest review on exactly that idea — general health checks in people without symptoms — found no demonstrable effect on illness or death. We saw that pattern recur across several providers in this market, not just one supplier. Our own assessment of these four services doesn't change because of it: the lab quality and the collection method are well supported, and that remains the reason we list them on PeptideCompare.
Sources
- Krogsbøll LT, Jørgensen KJ, Gøtzsche PC. General health checks in adults for reducing morbidity and mortality from disease. Cochrane Database of Systematic Reviews, 2019. www.cochranelibrary.com
- Phillips WR, Thompson DJ. Multi-Test Screening and the Chances of Being Normal. The Journal of Family Practice, 1980;11(7). www.mdedge.com
- Interpretation of laboratory results. Acute Care Testing (Radiometer). acutecaretesting.org
- Comparison of laboratory results and pain perception in self-sampled capillary blood versus venous blood sampling: a systematic review and meta-analysis. Clinical Biochemistry, 2025. www.sciencedirect.com
- Biological variation of immunological blood biomarkers in healthy individuals and quality goals for biomarker tests. BMC Immunology, 2019. link.springer.com