How we evaluate longevity hardware.

Three rules of buying longevity hardware

1. Single-purpose beats multi-function. A great cold tub is better than a so-so cold-tub-with-sauna combo. Most multi-function longevity products underdeliver on every individual function compared to category leaders.
2. Warranty is the spec. A 1-year warranty on a $5,000 product is a tell. We weight warranty depth heavily. Cabin and chiller warranties get reported separately because they often differ.
3. Owners outvote reviewers. A product with 200 verified owner reports beats one with 12 magazine reviews. We weight what long-term owners report over what a single-product reviewer saw in a week.

The scoring rubric

Deep-reviewed products receive a score from 1.0 to 10.0. Scores are calibrated against the category, not against the entire site - an 8.5 cold plunge is comparable to an 8.5 sauna in relative quality, not in absolute spec.

Per-category weighting (approximate):

• Build quality & materials (20%) - construction grade, sourcing, durability under expected use cycles.
• Performance against category benchmark (20%) - how it stacks against the category leader on the spec that matters most (e.g., for cold plunges: temperature stability and minimum °F).
• Warranty & service (15%) - cabin warranty, component warranty, dealer/service network depth.
• Value (15%) - price relative to spec, not absolute price. A $9K tub can score higher on value than a $4K one if its spec/price ratio is stronger.
• User experience (10%) - install complexity, ergonomics, daily-use friction.
• Brand track record (10%) - years in market, installed base, founder transparency, regulatory standing.
• Smart features / ecosystem (10%) - app quality, integrations, programming flexibility.

What disqualifies a product

We will not include a product in the Vault if any of the following is true:

• Brand makes medical or outcome claims that aren’t backed by published research at the dose / use case sold.
• Warranty is shorter than 12 months on hardware over $1,000.
• Brand has been the subject of FTC, BBB, or NAD enforcement on affiliate disclosure within the last 24 months without remedy.
• Product is sold primarily through paid-influencer promotion with no editorial review presence.
• Brand requires affiliates to use specific marketing language that overstates outcome claims.

Pricing freshness

Every product’s price field carries a verifiedAt date, printed beside the price: the day an editor last checked that price against the manufacturer or retailer. Two layers keep it current.

• An automated daily check. Every day at 09:00 UTC a scheduled job reads the current price from the brand’s own store data (Shopify product data or schema.org offers) for the products whose store it can read. Not every store allows it, and Amazon listings are never read this way. Each reading is recorded, dated and sourced, for the price history shown on product pages and for price-drop alerts; a reading far from the verified price is not recorded and is flagged for editorial review instead.
• Editor re-verification. The price shown on a page changes only when an editor re-verifies it against the manufacturer’s page and stamps a new verifiedAt date. Movement caught by the daily check can prompt that re-verification but never replaces it. Our target is to re-verify every published price at least once a quarter; the date printed with each price shows when it was last verified, so a price that has gone longer is visible as such. Where a brand sells only by consultation and publishes no price, the stored figure is an editorial estimate from research and is reviewed on a longer cycle, because there is no published price to check it against.

Promotional discounts (subscribe-and-save, founder pricing windows, multi-bottle bundles) are noted in the price description but not factored into the displayed range unless they represent the standard buying path.

Editorial firewall

We earn commission on most outbound product clicks (read the full affiliate disclosure). Editorial scoring and ranking are walled off from commission economics. Specifically:

• Rankings and scores are never for sale. We do accept clearly labeled sponsored features and paid brand placements, and they are always disclosed and kept separate from editorial rankings.
• Higher-commission programs don’t rank higher. Our top-ranked sauna pays under 10%; we recommend it anyway.
• We disclose commission ranges per program on the disclosure page.
• When a product we previously recommended drops in quality (warranty cuts, brand issues, regulatory action), we update or remove the review - even if it’s an active commission source.

Updates and review cadence

New products are added on a rolling cadence. Our target is to re-verify existing reviews each quarter for pricing, warranty terms, and brand standing; between those passes, the automated daily price check described above records price movement on the products it can read. Major product updates (new model release, brand acquisition, FDA action) trigger an immediate review revisit. Spotlights and deep reviews carry a publishedAt and updatedAt date so you can see how fresh the editorial is.

Found something we got wrong? Email ryan@lifespanvault.com with the page URL and what we missed. We update reviews when the facts change - corrections are visible in the updatedAt field.