First, Do No Harm

Probably fewer than you think, and maybe none at all. Sleep, food, training, and relationships will do more for you than anything we sell. If your diet covers your needs and there isn't a specific, evidenced outcome you're after, you don't need to take anything. If you do decide to take something, check it against the evidence first. The Formulary lays out that evidence for every ingredient we've reviewed.

Our U.S. manufacturing facility is FDA-registered, NSF-certified, UL-registered, SQF-certified and GMP-certified. Every finished lot is tested by an independent, ISO 17025 accredited laboratory for identity, heavy metals, and microbials, and we publish the complete numerical results, so you can look up the exact contents of your lot. We don't currently hold NSF product certification. We're in the process of it and look forward to adding one more independent check. If you compete under a governing body that requires NSF Certified for Sport products, check its rules before supplementing.

Because almost nothing clears our standard: proven safe in humans, proven effective in humans. We'd rather make the definitive version of five things than a mediocre version of fifty. We reviewed the 100 most popular supplement ingredients and rejected 95. Three more products are in formulation now.

Every order is covered by a 60-day guarantee. If you're not satisfied, return it within 60 days of delivery for a refund or replacement, for any reason. Full details are in our Refund Policy. Start a return through our returns portal.

We ship within the United States. Orders ship from our US fulfillment center within 1 business day.

Yes. Every batch is third-party tested, and you can look up the results by lot.

In our U.S. manufacturing facility, which is NSF-certified, UL-registered, SQF-certified and GMP-certified.

We review ingredients rigorously and publish our reasoning in the Formulary. We only sell what we'd take ourselves. Of the ingredients we've reviewed, we've rejected 95%.

In three steps. First, Aaron Esagoff, MD (Johns Hopkins School of Medicine) reviews the clinical evidence and decides whether the ingredient is worth selling, in what form and at what dose. Second, every physician on our medical advisory board reviews it independently. All of them must agree that the evidence is clear and supports safety and efficacy across a robust set of human trials, that the dose and form match the evidence, and that they support the exact version we sell. Third, once it is sourced and produced, the board signs off again on its sourcing, our manufacturing quality and its independent test results. Final sign-off takes a unanimous board. See the full review process.

Every lot goes through three distinct stages of testing. The raw ingredient is tested before it ships to our manufacturing facility, tested again when it arrives, and the finished product is tested once more after it is filled. Every lot's results are published on our testing page.

We don't sell it. Every lot is tested against our stringent limits. If a result comes back outside a limit, we retest to verify. If it is still out of spec after retesting, the lot is rejected and never sold. See how testing works on our testing page.