Buying Guides

Ranked, evidence-first buying guides. We include competitor products wherever they earn a place, and we say plainly when one of ours is the pick.

All buying guides

  • Best NMN + NR Supplements in the US (2026 Buyer's Guide) — We compared nine NAD+ precursor products sold in the US, verified on each brand's own site on October 13, 2026, against six criteria: dose versus the human trials, lot-level testing, form, cost per day, fillers, and serving honesty. Seven made the ranking. Tru Niagen wins on clinical history for NR alone. For a combined NMN + NR capsule with a public lot certificate, our own product takes the top spot, and the math is shown rather than asserted.
  • Best Vitamin D3 + K2 Supplements (2026 Buyer's Guide) — We compared seven vitamin D3 + K2 products sold in the US on dose against the trials, K2 form, carrier, testing, fillers, and real cost per day, with every price checked on the brand's own site on October 13, 2026. For most people the answer is 5,000 IU of D3 with 100 to 180 mcg of MK-7 in oil for under $0.40 a day. We make one of the three products that hit that mark, and NOW's capsule beats ours on K2 dose.
  • Best Probiotics with Akkermansia (2026 Buyer's Guide) — We compared the Akkermansia muciniphila supplements actually sold in the US on five criteria: dose against the one human trial, live versus pasteurized cells, whether the count is guaranteed through expiration, testing you can see, and real cost per day. Pendulum has the most human-trial history. For most people who want Akkermansia plus a conventional probiotic in one capsule, the value pick is ours, and the math is on the page so you do not have to take our word for it.
  • Best Nootropic Supplements for Memory and Focus (2026 Buyer's Guide) — We verified eight nootropic products on their own websites on October 14, 2026 and ranked six by one rule first: does the label dose match the human trials? Only two ingredients clear that bar in healthy adults, citicoline at 250 to 500 mg and standardized bacopa at 300 to 320 mg. Mind Lab Pro wins the tested-formula category and Jarrow wins budget. For most people our own Brain Advantage is the pick, and we show the math rather than ask for trust.
  • Best Magnesium Supplements for Sleep (2026 Buyer's Guide) — We compared six magnesium supplements on the number most labels obscure, elemental magnesium per serving, then on dose against the sleep trials, form, proof of testing, and price per day. Every price and label was read from the brand's own site on October 14, 2026. For most people the answer is a 200 mg chelate capsule under $0.40 a day. Doctor's Best is the cheapest verified; Thorne is the best certified. We make two of the six.
  • Best Daily Vitamins and Multivitamins with Adequate Vitamin D (2026) — Most multivitamins contain just 400 to 800 IU of vitamin D, which is the bare minimum RDA and potentially not enough for optimal health. We evaluated daily vitamins across four categories to find the ones that actually deliver adequate D3 along with the rest of your essentials.
  • Best Urolithin A Supplements in the US (2026 Buyer's Guide) — We compared the Urolithin A supplements actually available in the US on the things that matter: dose versus the clinical research, purity and third-party testing, manufacturing transparency, and real cost per day. Here's what we recommend and why, including our own and the competitors we respect.
  • Best Vitamin D Supplements 2026: What to Look For and What to Avoid — We evaluated vitamin D3 supplements across six categories, looking at form, dosage accuracy, absorption, third-party testing, additional ingredients, and value per IU. Here is what we actually recommend and why, including a few of our own and a few we respect from other brands.