Last updated November 3, 2026

Privacy Policy

N of 1 runs at-home product studies: you test a product on yourself for a few nights and get your own answer. To do that we ask about your sleep and how you feel, which is health information. This page says exactly what we collect, why, who sees it, and what you can do about it.

The short version: we use your answers to run your study and to publish group results without your name. We don't sell your information, we don't give your answers to advertisers, and you can ask us to delete everything at any time.

Who we are

N of 1 by Evident Reviews (“N of 1,” “we,” “us”) is run by Evident Health LLC. This policy covers the N of 1 website, sign-up, study pages and study emails. The rest of getevident.co is covered by Evident's Terms of Use and Privacy Policy.

Evident Health LLC owns Sleep Karma (sleepkarma.co). Some N of 1 studies test Sleep Karma products, including the mouth tape study, and study kits are checked out on the Sleep Karma store. We say so on every study that involves one.

What we collect

When	What
You ask to hear about the next study	Your email and, if you give it, your first name. We email you once when a study opens, then delete it within 30 days, or as soon as you sign up for a study. It's used for nothing else.
You sign up	First name, email, the time you usually wake up, your time zone, which sleep tracker you wear (if any), what bothers you most about your sleep, whether you've used the product before, whether you want to hear about future studies, and when you agreed to this policy.
Safety questions	Your answers are checked on your own device. We only receive whether you passed. We don't store the answers themselves.
You pay for shipping	Checkout happens on the Sleep Karma store (sleepkarma.co), a Shopify store owned by Evident Health LLC. Shopify collects your shipping address and payment. N of 1 only receives your order number, when you paid and when your kit shipped. Card details never reach N of 1.
Before your study	Your guess about how much the product will help, where you'll keep it, your plan for night one, and when your kit arrives.
Each morning	How rested you feel (1 to 5), your energy (1 to 5), whether you woke with a dry mouth, whether you used the product as planned, your tracker's sleep score if you choose to share it, anything you choose to note, a skin check on product nights, and the time you checked in and whether it was on a phone or computer.
If something goes wrong	What you report (for example skin irritation or trouble breathing) and any note you add.
At the end	Your answers to the last questions (experience, comfort, skin irritation, the biggest change you noticed, whether you'd keep using it or recommend it) and your choices about being quoted, contacted for a case study, or credited.
How you found us	If you arrived from a link with tracking tags (for example from an ad or a newsletter), we save those tags and the website you came from with your sign-up, so we know which channels bring testers. If we were testing two versions of the page's wording, we also save which versions you saw.
Using the site	Our hosting provider keeps standard server logs, such as IP address, browser and the page requested, to run and protect the site.
You email us	Whatever you write to us.

What we don't collect

Your safety-screening answers (only pass or not).
Payment card details.
Data pulled from your sleep tracker. We only see a score if you type it in.
Your precise location. Your time zone is all we use.

How we use it

To check a study is a safe fit for you and to run it: your schedule, reminders, check-ins and make-up nights.
To show you your own result at the end, comparing your nights with and without the product.
To follow up on safety reports. A report pauses your study and a person on our team writes to you.
To analyze the study and publish group results (see Published results).
To email you about your study, and about future studies only if you said yes.
To understand which channels bring testers who finish, using the tags described above.
To keep the service working and secure, and to meet legal obligations.

Consumer health data

This section is our Consumer Health Data Privacy Policy. It applies to everyone, and it's written to meet laws such as Washington's My Health My Data Act and similar laws in Nevada and Connecticut.

What counts as health data here

Your sleep and symptom answers (how rested you feel, energy, dry mouth, skin reactions, problem reports, sleep tracker scores, notes and final answers), what bothers you about your sleep, and the fact that you took part in a study of a sleep product.

Why we collect it and where it comes from

Only to run your study, keep it safe, give you your result and publish group results, as described above. It comes from you, through the sign-up and study pages.

Your consent

We ask for your consent to collect your health data as its own step at sign-up, separate from agreeing to the Terms. You can withdraw it at any time by emailing studies@getevident.co. We then stop collecting it and delete what we hold, except the minimum the law requires us to keep.

Who receives it

Only the service providers that run N of 1 for us (see the next section), under contract, to provide their service. We don't sell health data, and we don't share it with anyone else, including Sleep Karma and advertisers, without your separate consent. The only exception is a group summary that can't identify you (see Published results).

Your rights

You can confirm whether we hold your health data, see it, get a list of who we've shared it with, have it deleted, and withdraw consent. See Your rights and choices for how.

Service providers that run N of 1 for us, only to provide their service: Vercel (hosting), Neon (database, stored in the United States), Resend (sending study emails) and Shopify (checkout and orders on the Sleep Karma store).
ShipBob, our fulfillment partner, packs and ships your kit. It receives your name, shipping address and order from the Sleep Karma store, and nothing about your study answers.
The N of 1 team at Evident Health, who each sign in with their own account and see what they need to run studies and answer you.
Group results that can't identify you, for example “20 of 24 testers rated their sleep better.” We share these publicly and with brands, including Sleep Karma. Groups smaller than 10 people are never shown.
When the law requires it, or when someone's safety is at risk.
If Evident's business changes hands, this information may move with it, still covered by this policy.

We don't sell your personal information, and we don't share it for targeted advertising.

Published results and your words

When a study is published we show group numbers and methods, never your name or email. Your own answers stay private.

Quotes: we only quote what you wrote if you ticked “You can quote what I wrote,” and only with your first initial. Where quotes can appear, and how to withdraw, is in the Terms.
Credit: only if you ticked it, with your first initial and tester number.
Case studies: if you said you're open to one, we'll email you first and you can say no.

Cookies and ads

On the landing and sign-up pages we set two first-party cookies. n1_src (30 days) holds the tracking tags of the link you arrived from, so we can save them with your sign-up. n1_vid (1 year) is a random ID with no personal information in it. When we test two versions of a line of text, it makes sure you keep seeing the same one, and lets us count how many visitors saw each. If you sign up, which versions you saw is saved with your sign-up.
N of 1 doesn't use advertising pixels or third-party analytics right now. If we add them, they'll run only on the public landing and sign-up pages, they'll never receive your answers, and we'll update this policy before they go on.
Your study pages and check-ins never carry ads, pixels or analytics.

How long we keep it

Study records (sign-up, check-ins, reports, final answers): until 3 years after your study ends, then we delete them or strip anything that identifies you. Published group results stay up.
Future-study list: until you ask us to take you off.
“Tell me when the next study opens” list: 30 days after we email you that a study is open, or until you sign up, whichever comes first.
Cookies: n1_src for 30 days and n1_vid for 1 year, in your browser.
Server logs: as long as our hosting provider keeps them, which is short-term.

You can ask us to delete your records sooner at any time.

Security

The site only runs over encrypted connections (HTTPS), and the database is encrypted at rest.
Only the N of 1 team can see study data, each with their own password-protected account. We can remove anyone's access instantly.
Your study page opens from a personal link in your emails. Anyone with that link can open your page, so please don't forward it. If you think someone else has it, email us and we'll send you a new one.

No system is perfectly secure. If a breach affects your information, we'll tell you as the law requires.

Your rights and choices

Stop at any time. Leaving a study is always fine, and you keep the product.
See, correct or delete your information, or get a copy of it.
Know who we've shared it with.
Withdraw consent to us using your health data.
Stop study and future-study emails. Reply to any email or write to us.

To use any of these, email studies@getevident.co from the address you signed up with, or reply to any study email. We confirm it's you by writing back to that address, then respond within 45 days. If we turn down a request, you can appeal by replying to our answer with “appeal”; we'll respond within 45 days, and if you're still not satisfied you can contact your state attorney general. We won't treat you differently for using your rights.

Depending on where you live (for example California, Washington, Nevada, Connecticut, Colorado, Virginia), you may have more rights under state law. We honor these requests for everyone, wherever you live.

Adults only

N of 1 studies are for people 18 and older, and we ask at sign-up. We don't knowingly collect information from anyone younger. If you think we have, email us and we'll delete it.

Changes

When this policy changes we update the date at the top. If a change affects how we use information we already have, we'll email you before it takes effect, and for health data we'll ask for your consent again.

Contact

Evident Health LLC, N of 1 team: studies@getevident.co. By mail: Evident Health LLC, 30 N Gould St Ste N, Sheridan, WY 82801. See also our Terms.

Questions about this page: studies@getevident.co. Evident Health LLC.