✶ Written by an AI · fact-checked by a doctor

Articles

One question per article, answered at the top, then shown its working. Every factual claim here traces back to a primary source that a practising doctor actually read. When a claim doesn't survive that check, it doesn't get written down.

Vitamin D

No Do You Actually Need a Vitamin D Supplement If You Get Sun? If you already spend time outdoors, the case for a daily vitamin D capsule is thinner than the shelf suggests — here is who the evidence actually supports supplementing. From The Vitamin D Myth

Cold exposure

No Does Cold Plunging Raise Testosterone? The testicles-are-outside-the-body argument sounds airtight and does not survive contact with a blood test. Here is what was measured, and the citation this book's own fact-check had to throw out. From Is Cold Plunging Actually Worth It?

Colostrum

Partly Does Colostrum Survive Your Stomach? Some of it does — and that is a smaller claim than the one being sold. The gap between antibodies surviving digestion and antibodies entering your bloodstream is the whole argument. From Does Colostrum Actually Work?

Melatonin

Partly Does Melatonin Work the First Night? If melatonin is going to do anything for you, it does it straight away — and what it does, on average, is about seven minutes. Here is why the first night feels like a verdict and isn't one. From Does Melatonin Actually Work?

Seed oils

No Does an Oil's Smoke Point Actually Matter? Smoke point is the number every chart is built on and the one the industry does not use to judge a frying oil. What actually gets measured, and what that changes in a home kitchen. From Are Seed Oils Actually Poisoning You?

Inflammation

It depends How Would You Know If You Had Chronic Inflammation? The symptom checklists circulating online describe almost everyone. Here is what chronic inflammation actually is, what a CRP result can and cannot tell you, and the signs that warrant a GP. From Not Another Anti-Inflammatory Diet Book

Creatine

No Is Creatine Bad for Your Kidneys? What the Studies Measured The kidney fear rests on a blood marker that rises for a reason that has nothing to do with damage. Here is what the trials measured, and where the reassurance genuinely stops. From Is Creatine Actually Safe?

Vagus nerve

Partly How Long Do Vagus Nerve Exercises Take to Actually Work? Humming, gargling, cold water, slow breathing — graded by what the evidence actually shows, and how long each one takes to do anything measurable. From The Vagus Nerve, Decoded

How this is made

Herbs and adaptogens

It depends How Long Until Liver Enzymes Recover After Stopping Ashwagandha? What the published ashwagandha liver-injury cases actually show about recovery time after stopping, who is most at risk, and the warning signs that mean see a doctor. From Adaptogens, Checked

Cortisol and stress

Partly How Do I Know If My Puffy Face Is Cortisol or Something Else? A practical way to separate ordinary morning puffiness from the rare, progressive facial change of real cortisol excess — with the tests that actually answer it. From The Cortisol Myth

Blood glucose

No Is a CGM Worth It If You Don't Have Diabetes? What a continuous glucose monitor graph can and cannot tell someone without diabetes — the real numbers, the borrowed targets, and the limitation no sensor fixes. From Glucose Spike Check

Magnesium

Not proven Magnesium Glycinate vs Threonate for Sleep: Which Is Better? No head-to-head trial has ever compared magnesium forms for sleep. Here is what each form actually has behind it, and what the label is not telling you. From Magnesium: More Hype Than Miracle