Terms, privacy and the disclaimer
What the book claims for itself, where its author sits, how corrections work, what being thanked in it means, and what this site does and does not collect. None of it is long.
What the book says about itself
This is what the disclaimer the book carries on page 4 says, in short. Every page also carries a one-line running foot saying the book is information and not medical advice.
It is information, not medical advice. Neither the book nor this site is a substitute for a doctor, a pharmacist or a nurse, and reading either puts nobody in anyone’s care. Nothing in it is written about a particular reader; the named people in the situations chapter are invented.
Never start, stop or change a medicine because of this book. Where a page says something needs adjusting, treat it as a question for your doctor or your pharmacist.
The clinician outranks the book. Where the book contradicts what your own clinician has told you, the clinician is right and the book is wrong, and it says so. Do not delay care because of anything you read; if something worries you, get it looked at.
The numbers are not universal. Thresholds, doses, prescription status and reporting duties differ by country, so the book names the issuing body behind almost every figure rather than writing to one jurisdiction, and says on the page when a figure is the author’s own working rule instead. Use the one that applies where you live.
It is written for adults. The one exception is the infant safe-sleep guidance in situation 12, which follows the AAP and Singapore’s HealthHub as they stood when the book was written; check the current guidance before acting on it. It points repeatedly to the warning-signs page, page 72, which sets out what belongs to a clinician rather than to this book.
The conflict you should weigh the book against
I am not a doctor and I am not a researcher. I am in the wellness industry, and you should not have to take my word for what that means: my work there includes sleep supplements, and overlaps directly with the supplement pages in this book. The book recommends no product, brand, or company. Where a real name appears, it is a source being cited or a method being compared. What it covers is my reading of the published evidence on the basics worth getting right before anything else, graded, with the gaps marked. The support chapter opens by trying to talk you out of most of what is in it. Read the book knowing that.
What I do not promise
The book is a reading of the evidence as it stood when it was written, and evidence moves. Studies conflict, good ones get overturned by better ones, and a finding that looks solid at one sample size can shrink or vanish at a larger one. I have traced almost every claim back to the document it rests on, and graded most of them. None of that makes it right. It is offered as it is, with no guarantee that it is complete, current or suited to any particular reader, and it is not a substitute for professional advice. Nothing here is meant to exclude any liability that cannot lawfully be excluded.
Corrections
Write to [email protected] with the page number, or the line’s address on Every source, graded, and what is wrong with it. Where you are right about the evidence, the book changes: the correction goes on the corrections page with the date, the sources page is updated, and the next printing carries it. Copies already printed cannot be changed.
I will not quote you without your agreement to the exact words, on the corrections page or anywhere else. If a correction is credited, it is credited in wording you have seen.
What an acknowledgment means
Before publication I asked the researchers and clinicians whose work the book cites, and some whose field it covers, to read the pages that concern them. Those who agreed to be named are thanked in the acknowledgments, in wording each of them saw first.
An acknowledgment is a thank-you for time given, not an endorsement of the book, of any claim in it, or of me. Nobody named there is holding out the book as correct, and the acknowledgments page says so: being listed is not an endorsement of the book or of me.
Anyone named can come off, for any later edition that is mine to change, by writing to [email protected]. Beyond citing published work on Every source, graded, no reviewer’s name or affiliation is used in marketing or in anything promoting the book or my other work; the author of the foreword is named as such, on the title page and on this site.
What is collected, and what is not
Nothing, by me. This site sets no cookies, runs no analytics, and has no form, mailing list or account. There is nothing to sign up to. The hosting provider keeps its own request logs, including IP addresses, for its own security and billing; I do not use those logs and I have added nothing to them.
The sample PDF is a plain download. Nothing is asked for it, and I record nothing; the host’s request log described above is the only trace.
Buying the book happens on Amazon. The buy link leaves this site, and from that point Amazon’s own terms and privacy notice apply.
If you write to me, I hold your message and your address in order to reply, and a working note of corrections and who sent them. I keep them for three years from the last message either of us sent, and then they go, as far as it is in my hands: my email provider keeps its own backups on its own schedule. The one thing that outlives that clock is a name whose owner has agreed to appear in the acknowledgments, kept for as long as the book is in print so that a withdrawal is something I can still act on. I hold it because I need it to reply to you and to keep an accurate record of corrections, and for nothing else. Ask what I hold, ask for a copy, ask me to correct it or ask me to delete it: [email protected]. If you would rather raise it with a regulator, in Singapore that is the Personal Data Protection Commission, and in the UK or the EU your national data protection authority.
Who else sees it. Two providers, because email and websites do not work without them: my email provider, and the hosting provider above. Both are outside Singapore, so an email you send me crosses a border to reach my provider. Nobody else receives your details, apart from those two providers, and I do not sell or share them.
Rights. © 2026 Chris Ngoi. All rights reserved. Quote a short passage with attribution; do not reproduce the book, or the sample, whole or in substantial part. Every source, graded may be linked to freely, line by line.
Published by Chris Ngoi, Singapore. Last updated September 9, 2026.
Who to write to
Corrections, disagreements, the acknowledgments, and anything about your own data:
[email protected].
Anything else: [email protected].