Inside the Formula | AG1: Three Products Put to the Test

With AG1 & TESTED by SuppCo: Inside the Formula is a new sponsored series featuring brands in the TESTED by SuppCo certification program, where we spotlight the fascinating research behind products that have received the certification. Learn more about TESTED by SuppCo.

Behind every supplement label is a simple question: is what’s on the label actually in the bottle? Here’s how three AG1 products answered it. 

SuppCo tested three AG products: AG Vitamin D3+K2, AG Omega3, and AG Omega3 + CoQ10. These were a natural starting point because each lists a clear amount for every active ingredient, which is exactly what identity and potency testing is built to verify.

Ralph Esposito is a naturopathic doctor and licensed acupuncturist, certified in functional medicine, and he spent years in clinical practice before becoming AG1's Chief Science and Nutrition Officer. In that practice, he kept seeing the same pattern: patients who ate varied, healthy diets and still dealt with gas, bloating, and indigestion. Eating well, it turned out, wasn't the same as absorbing well.

That observation has shaped how AG1 is built. A traditional multivitamin is insurance against dietary gaps, the kind of thing people might take for years without ever feeling a difference. AG1 pairs that foundational layer, including methylated B vitamins and an activated form of vitamin B6, with five clinically supported probiotics aimed at supporting the gut. The logic is simple. If the gut isn't working well, the rest of the formula has a harder time doing its job.

The same discipline applies to what AG1 says about its products. Every ingredient goes through a review of the supporting research, and the science team signs off on public-facing claims, not just formulas. Sometimes that means saying less than they're allowed to. "We don't put a claim out there and wait to see if someone challenges it," Ralph told me. "If the literature doesn't convincingly support it, we don't say it… even when we technically could."

AG1 promotes numerous gold-standard clinical trials on its website, but human trials are only one rung of a much taller ladder. At the bottom, raw materials are tested to confirm they are what suppliers say they are, from botanicals to vitamins. Above that sits preclinical work, including a gut simulator that models how AG1 behaves inside the digestive tract, something that's hard to observe directly in a person. Ralph compares the sequence to drug development, where you build a mechanistic case before you ask human volunteers to take part.

Then there's the research that doesn't involve AG1 at all. The company has partnered with several universities to study nutrient status and gut health in people taking GLP-1 medications, a population growing fast in clinical care. Participants aren't given AG1; the goal is to understand what this group actually needs before anyone decides what to build for them. "As scientists and clinicians, we have a responsibility to move the research forward," Ralph said, "not just for our own products, but for the field."

That mindset reaches the loading dock, too. Quality, supply chain, procurement, research, and regulatory teams all flag concerns about incoming materials, and anything that doesn't meet spec gets rejected and sent back, even when that means delays, added cost, and pressure on the supply chain. The people making those calls include PhDs, physicians, and registered dietitians with backgrounds in molecular medicine, the microbiome, and clinical nutrition. One dietitian who joined the company recently told me the biggest surprise was how much time and money goes into science that consumers rarely see.

You can see that attention in AG1's newer products. AG Omega3 and AG Omega3 + CoQ10 carry IFOS (International Fish Oil Standards) certifications, the quality mark Ralph recommended to patients for years, because oxidation and rancidity are some of the first things people worry about with fish oil. AG Vitamin D3+K2 reflects decisions most buyers will never notice, like which form of K2 to use and whether it's the cis or trans form, which affects how well it works.

Those are the three products we put to the test. To earn the TESTED by SuppCo certification, we purchased AG Vitamin D3+K2, AG Omega3, and AG Omega3 + CoQ10 anonymously, the same way any customer would, with no samples and no advance notice. We sent all three to an independent, ISO 17025-accredited lab, which tested them for identity and potency. All three were confirmed: what's on the label is what's in the bottle, at the amounts listed. That matters here more than most places, because a D3+K2 product lives or dies on using the right form at the right dose, and an omega-3 is only as good as the quality its label promises.

What the Testing Doesn't Show You

AG1 is a very visible brand in the supplement world.  I spent years in a lab studying ingredients like creatine and beta-alanine, so I look closely at any all-in-one formulas with long ingredient lists… which tend to make me ask more questions, not fewer.

What stood out to me about AG1 was its GLP-1 work. Rather than starting with a product, the team is partnering with universities to understand what GLP-1 users need, both nutritionally and in the gut, before deciding what to make. Studying a population before designing for it is a step most companies skip.

The same team walks back overzealous claims and sends back raw materials at real cost, which suggests more discipline than you’d expect from the outside. AG1’s flagship formula already has four randomized controlled trials behind it, and the GLP-1 research is now underway.

The GLP-1 results aren’t published yet, and the gut simulator data comes from a model rather than people, so human findings will be the real test. But the order of operations is right: ask the question first, then build the product.

So next time you come across an AG1 ad, or pass by it in your local retailer, know there's a lot more going on behind that logo.

AG1, welcome to the TESTED by SuppCo family.