Vagilant vs. Evvy vs. Daye
How Vagilant compares to Evvy and Daye on method, evidence, cost and what each is actually for, including where the others are ahead of us.
We make one of these products.
This is a comparison written by Vagilant about Vagilant and two competitors. We have tried to be accurate and to state clearly where the others are better than us. Read it knowing who wrote it, and check the primary sources.
Evvy, Daye and Vagilant are frequently mentioned together, but they are not really the same kind of product. One sequences your microbiome, one is a diagnostic collection device, and one is a wearable monitor. Choosing between them starts with deciding what you actually want to know.
Side by side
| Vagilant | Evvy | Daye | |
|---|---|---|---|
| What it is | Biosensor panty liner + online assessment | Mail-in vaginal swab | Mail-in diagnostic tampon |
| Method | Nine colorimetric pads read during ordinary wear | Metagenomic sequencing (mNGS) | PCR against a target panel |
| What you learn | Chemical change over time, in context | Full microbial community, hundreds of organisms | Presence of specific listed organisms, incl. STIs |
| Turnaround | Same day | 1–3 weeks | Days to weeks |
| Repeatable often? | Yes, designed for it | Costly to repeat | Costly to repeat |
| Published validation | No, internal testing only | Yes, peer-reviewed | Yes, published performance figures |
| Market | US & Canada (pre-launch) | US | UK / EU |
| Cost | Not yet set | ~$130–250 | ~£100+ |
Evvy
US-based, using metagenomic next-generation sequencing on a single at-home swab to identify hundreds of organisms and their relative abundances, returning a detailed report on your microbiome including community state type.
Where Evvy is ahead of us: published, independently validated methodology in the peer-reviewed literature, with reported sensitivity around 93% and specificity around 90%. We have nothing comparable. They also identify specific organisms, which we cannot do at all, and they have a large body of published educational content and an established US presence.
Trade-offs: cost and a one-to-three-week turnaround make frequent repetition impractical, so it is better at depth than at trend. More data is also not automatically more actionable: detecting an organism does not establish it is causing symptoms, and a diverse microbiome is normal for a substantial proportion of people. See the microbiome article.
Best for: recurrent or unexplained symptoms where you want the fullest possible picture, ideally interpreted with a clinician.
Daye
UK-based, using a diagnostic tampon rather than a swab. The tampon samples across the vaginal canal rather than one point of contact, which is a genuinely thoughtful design decision, since swab sampling can miss depending on placement. Analysis is by PCR against a defined panel, and screening options include STIs and HPV.
Where Daye is ahead of us: published performance figures for its collection method, an actual product on sale, an established clinical service, and substantial UK press coverage.
Trade-offs: PCR only detects what is on the panel. Anything outside it is invisible, so a negative result means "none of the listed targets" rather than "nothing". Daye has not published peer-reviewed validation of its microbiome screening methodology comparable to Evvy's. Availability is UK and EU, so it is not an option for most North American readers.
Best for: UK readers wanting broad screening including STIs from a single at-home sample.
Vagilant
Ours. Nine colorimetric biosensor pads on a liner you wear normally; you read the grid, enter what you see in an online assessment, and get a report the same day. No lab, no posting, no waiting.
What we think we do better: repetition. Every other option is a discrete testing event with cost and delay attached, which makes frequent use impractical. A liner you wear anyway has low enough friction to use repeatedly, and repeated measurement is how you establish a personal baseline and notice when something departs from it. Vaginal chemistry moves constantly (see across your cycle), so a single snapshot is intrinsically limited, however precise. Same-day results also matter when you have symptoms now.
Where we are behind, plainly:
- No independent validation. We have internal testing with volunteer users and no peer-reviewed publication. Evvy and Daye both have published figures; we cannot quote any. This is the most important line in this article.
- No organism identification. Chemical change is not species identification. We cannot tell you that you have Gardnerella.
- No STI screening. At all.
- Not on sale. We are pre-launch. Both alternatives are products you can buy today.
Our full position, including what has and has not been established, is on the science page.
Choosing
| If your priority is… | Then |
|---|---|
| The most complete picture, once | Evvy |
| STI screening included | Daye (UK) or a US mail-in STI panel |
| Tracking change over months | Vagilant, or a written log, which is free |
| Published evidence behind the method | Evvy, then Daye. Not us, yet. |
| Something available today in North America | Evvy |
| A diagnosis | A clinician. None of the three diagnoses anything. |
These are also not mutually exclusive. Sequencing for depth when something is unexplained, and ongoing tracking for pattern, answer different questions.
What none of us do
None of these products is a substitute for clinical assessment. If you have symptoms, see a clinician, and bring whatever information you have. See talking to your doctor, and at-home tests compared for the wider category including cheap pH strips, which for the specific BV-versus-yeast question remain surprisingly good value.
Sources
- Evvy, published validation of mNGS methodology, Diagnostics; and Evvy's own Evvy vs. Daye comparison.
- Daye, published diagnostic tampon performance data, yourdaye.com/science.
- Centers for Disease Control and Prevention, STI Treatment Guidelines.
- Vagilant internal testing (unpublished).
Figures for competitor products are drawn from their own published materials and were accurate at the time of writing. Check directly for current pricing and availability.
This article is for general information and is not medical advice. Vagilant is a wellness product for health monitoring and education. It is not a diagnostic medical device and does not diagnose infections or conditions. If you have symptoms or concerns, speak to a doctor or other qualified healthcare provider.