How we research

Source hierarchy

For a health claim we use sources in this order:

1. Systematic reviews and meta-analyses of human trials, read from the published abstract or paper.
2. Randomised controlled trials in people, with sample size, duration and funding noted.
3. Regulators and official bodies: FDA, NHS, national and professional guidance.
4. Manufacturer pages for specifications, labels, ingredient amounts and prices, treated as claims, not evidence.
5. Independent reviewers' published measurements, cited by name, with any commercial tie they disclose.

Animal and cell studies are labelled as such and never presented as proof of an effect in people. When a study's authors or funders have ties to a product, the page says so.

What our evidence labels mean

• Strong: several human trials or meta-analyses agree, the effect matters, and long-term safety is established.
• Moderate: some human trials, but small, short or mixed.
• Emerging: mostly animal or mechanism studies, or very small human studies.
• Weak: little or contradictory evidence, no benefit shown, or a safety concern outweighs the evidence.

How prices and specs are checked and dated

Prices are the amount shown on the seller's own page on the date we read it, with the pack size and cost per serving or per study dose worked out in the open so you can redo the sum. Every page shows when it was last checked and keeps an update log for substantive changes. Prices and availability change faster than studies; treat any price as a dated reading, not a quote.

What we do not do

We do not test supplements, devices or wearables ourselves, and no page claims we did. There are no scores. A grade summarises published human evidence for a compound or device category; it is not a rating of any brand. Where an independent reviewer measured a product, we cite them by name and say whether they disclose a commercial tie.

Health boundary

Longevity Intel is for information only and is not medical advice. We quote the dose a cited study used and label it that way; we do not recommend doses or treatments. We never describe pages as medically reviewed: no named medical reviewer is attached to any page. Talk to your doctor or pharmacist before you start, stop or combine supplements, especially if you take medication, are pregnant, or have a health condition.

How pages are checked

Every fact is checked against its cited source, and each page gets a separate review pass before it is published. The corrections log lists what those reviews and readers have caught.

Open data

Cost per study dose data is public: github.com/hardcor3nl/longevity-cost-per-dose. See the cost per study dose table.

More

See About, the editorial policy, the corrections log and contact.