Last updated November 3, 2026

Terms

Agreeing to these terms

N of 1 by Evident Reviews is run by Evident Health LLC (“Evident,” “we,” “us”). When you sign up for a study you agree to these Terms and to our Privacy Policy. If you don't agree, please don't sign up. Checkout happens on the Sleep Karma store (sleepkarma.co), which Evident Health LLC owns, and is also covered by that store's own checkout policies, and the rest of getevident.co by Evident's Terms of Use.

Who can take part

• You're 18 or older and live in the United States.
• You pass the study's safety questions honestly. They exist to keep people for whom a product isn't a safe fit out of the study.
• One spot per person per study, using your own name and email.

Each study lists who can't take part, on its How it works page and in the safety check at sign-up. For the mouth tape study, you can't take part if any of these apply:

• You're under 18
• Diagnosed sleep apnea, or another diagnosed sleep disorder
• Your nose is often blocked, or it's hard to breathe through it
• You already tape your mouth at night
• Acid reflux at night
• A lung condition, like COPD or asthma
• An allergy to adhesives or tape
• Panic or anxiety when your mouth is covered
• You're pregnant
• 5 or more “yes” answers to a short set of sleep questions (for example loud snoring, or someone seeing you stop breathing in your sleep)

Not passing the safety check says nothing about your health. It only means that study isn't the right one for you, and it happens before you pay anything.

We can decline or end anyone's spot, for example if a study is full, if it isn't a safe fit, or if these terms aren't followed.

How a study works

• Each study page says what it tests, how many nights or days it runs, and the order of nights with and without the product. The order is fixed so results can be compared.
• When your kit arrives you do a short setup (for the mouth tape study: a skin patch test, a nose-breathing check and a plan for the first night).
• Each morning you answer a few questions, about a minute. If you miss a night we add a make-up night of the same kind. If you miss several, a person on our team may check in with you, and we may end your study.
• After your last night and a few final questions, you see your own result.

Taking part is voluntary. There's no payment for taking part.

The product, shipping and codes

• The product is free and yours to keep. You pay the shipping shown before checkout (for the mouth tape study, $6.95). Checkout happens on the Sleep Karma store (sleepkarma.co), a Shopify store owned by Evident Health LLC.
• Shipping isn't refunded once your kit has shipped, including if you stop early. If your kit never arrives or arrives damaged, email us and we'll make it right.
• Some studies give a discount code when you finish. Each code's amount and expiry are shown with it (for the mouth tape study, 20% off, valid 60 days). Codes have no cash value and can't be exchanged or transferred.
• We may change or cancel a study before it starts. If we cancel after you've paid and before your kit ships, we refund the shipping.

Your safety

• Follow the product's instructions and the study's setup steps, including any patch test.
• Don't take part if any of the conditions in Who can take part apply to you, or if a doctor has told you not to use the product.
• If you're unsure whether a product is right for you, ask a doctor before you start.

Not medical advice

N of 1 is not a medical service. Nothing in a study, your result, an email or a message from our team is medical advice, a diagnosis or treatment. Products in N of 1 studies are consumer products, and studies don't test them for treating or preventing any disease.

What results mean

Results are observational and self-reported: they compare what you told us on nights with and without the product. They aren't a clinical trial. Your result describes your own nights during the study. It isn't a promise about what a product will do for you later or for anyone else. When we publish a study's results, we share what we found, including when a product didn't help.

Your answers

You agree we can use your study answers to run your study and to analyze and publish group results without your name, as described in the Privacy Policy. We only quote your words, credit you or contact you for a case study if you chose that at the end of your study. Please answer honestly, including when a product isn't helping. That's what makes the results worth anything. Payment never depends on what you say.

Quotes and what you post

At the end of a study you can choose “You can quote what I wrote.” If you do, you give Evident Health LLC permission, without payment, to use what you wrote in your study answers:

• What: your words as you wrote them, or shortened without changing their meaning, with your first initial only (and your tester number if you also chose to be credited). Never your full name, email or photo.
• Where: getevident.co and sleepkarma.co (including study results pages), and ads for Evident and Sleep Karma.
• How long: until you withdraw it. To withdraw, email studies@getevident.co from the address you signed up with. We stop using your words in anything new within 30 days and take them down from our own sites. We can't recall printed materials or ads that already ran.

If you post about a study yourself, say what actually happened to you. Don't post claims about the study, the product or its results that you know are misleading, such as saying a product treats a condition, or presenting your own result as the study's.

Evident's stake

Evident Health LLC owns Sleep Karma, and some studies test Sleep Karma products. Each study says so when it applies. The study design, the questions and the rule that turns your answers into a result are set before the study starts and are the same whatever the product.

Your personal link

You don't need a password: your study page opens from a personal link in your emails. Keep it to yourself. Anyone with the link can open your page and answer for you. If you think someone else has it, email us and we'll replace it.

Don't misuse N of 1: no fake sign-ups, no answering for someone else, no attempts to break or overload the site.

Stopping

You can stop at any time, for any reason, by emailing studies@getevident.co or replying to any study email. You keep the product. We can pause or end your study for safety, if a study is stopped, or if these terms aren't followed. The sections on results, your answers, disclaimers and governing law still apply after you stop.

Disclaimers and limits

N of 1 is provided “as is.” To the extent the law allows, Evident doesn't promise the site will always be available or error-free, and isn't liable for indirect or consequential losses from taking part. Our total liability to you for anything related to N of 1 is limited to the amount you paid us for that study (the shipping). Nothing in these terms limits liability that can't be limited by law, such as for our own gross negligence, or your rights as a consumer under the law where you live.

Governing law

These terms are governed by the laws of the State of New York, without regard to its conflict-of-laws rules. Before filing any claim, please email us so we can try to fix it first. Any dispute that isn't resolved goes to the state or federal courts located in New York, unless the law where you live gives you the right to bring it in your home courts.

Changes and contact

If we change these terms we update the date at the top. Changes don't apply to a study you're already in unless you agree. Questions: studies@getevident.co, or by mail to Evident Health LLC, 30 N Gould St Ste N, Sheridan, WY 82801.

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