Proof.fit — Read the trials, not the affiliate links.

The supplement industry has a trust problem

Manual research is the tax for not trusting the industry.

A podcast mentions a supplement. The host’s affiliate link goes to a brand that owns the host’s brand. You don’t trust the link, so you do the work yourself.

Half an hour on PubMed. Fifteen minutes on r/Nootropics. Ten more reading the Examine page you’re paying for. Another ten cross-referencing whether the effect everyone keeps quoting was actually shown in humans, in a randomized trial, for the outcome you care about.

You’ve done this for creatine. For ashwagandha. For NMN, until you gave up on it. The Sunday-night research session has become a tax — the price of not believing anyone with a shopping cart attached to their podcast.

We built Proof.fit so you stop paying it.

How it works

Three steps. Read the trials yourself.

Step 1

Ask in plain English.

Type the supplement and the outcome you’d take it for — does ashwagandha help anxiety, is creatine worth it for cognition, what’s the evidence on NMN.
Step 2

Read the trials cited.

Every claim links to the underlying RCT — the gold-standard kind of human study. No paraphrase, no affiliate disclosure, no podcast clip standing in for evidence.
Step 3

Decide or skip.

Real evidence for the outcome you’re after? Worth a closer look. No evidence in humans yet? Skip it and keep your money. The whole loop fits in the time it takes the kettle to boil.

RCTs only

Not influencer opinions. Not animal studies. Not marketing claims.

Every supplement and every claimed effect on Proof.fit links back to one or more randomized controlled trials in humans — the highest tier of clinical evidence. If a supplement’s only support is mouse data or a podcast clip, we say so out loud instead of paraphrasing it as “research suggests”.

A list of three trial citations on Proof.fit, each linked to its source journal.

Proof.fit's Popular Benefits grid — Heart health, Energy, Antioxidant, Inflammation, Immune support, Digestive support.

Two ways in

Browse by supplement, or browse by benefit.

Start from the supplement (ashwagandha, berberine, glycine, creatine…) or start from the outcome you actually care about (heart health, energy, sleep, inflammation). Either way, you land on the same evidence — not a sales page.

Free at the lookup

No email gate. No paywall on the answer.

Ask any question, read any trial card, browse the full supplement and benefit index without signing up. Proof.fit doesn’t sell supplements, take affiliate revenue, or write content for influencers. Free at the lookup is the whole point.

You walk away knowing whether a supplement is worth a closer look or not, with the trial open in a tab.
You stop being the unpaid researcher inside someone else’s affiliate funnel.
You see the gap between what’s been studied in humans and what’s just been marketed.
You get to a verdict without an account, a card, or a “start your free trial” wall between you and the citation.

People who got their Sundays back.

Marcus K.

Software engineer, runs his own stack experiments

I cancelled Examine Insider after a month of using Proof.fit. Same trials, same rigor — but free at the lookup, and the chat answers the actual question I came with instead of making me skim a four-thousand-word article.

Aleksandra W.

Indie founder, building in public

Fadogia was on my next-month order because a podcast guest swore by it. Proof.fit pointed at the missing trials in humans in one paragraph. Saved me from a year of autopilot reorders.

Devon T.

Biology PhD candidate

How is a free consumer site doing better evidence triage than the supplement aisle of any pharmacy I’ve ever walked into?

Sara D.

Marketing director, Whoop user

I almost bought magnesium for sleep on a podcast tip. Proof.fit’s entry made it pretty clear the human evidence didn’t map to what I was about to add to my cart, so I closed the tab.

Built for readers from

r/Nootropics · r/StackAdvice · Brad Stanfield’s Discord · FoundMyFitness members · The Drive listeners · Hacker News · PubMed regulars · Examine Insider lapsers

Why we only use RCTs.

Randomized controlled trials are the gold standard of medical research. They eliminate bias through randomization and control groups, producing the most reliable evidence available about whether a supplement does anything in humans. Proof.fit indexes RCTs from major medical research databases — not blogs, not podcasts, not animal studies, not single-arm observational pieces.

What an answer looks like.

Ask whether ashwagandha helps with anxiety and you get a plain-English summary, the trials behind it (with author, year, and journal), the outcomes they measured, and an honest note when a popular claim isn’t backed by a randomized trial in humans. No paraphrase between you and the citation. No “click here to buy”. No newsletter wall.

One supplement, one question, one minute — and you’re done with the research session.

Try the chat

Try a question