Justin Mares raises $36M from a16z for Truemed to let Americans spend HSA/FSA dollars on gym memberships and supplements

Summary

Justin Mares has closed a $36 million Series A led by Andreessen Horowitz for Truemed, a fintech platform that lets Americans spend HSA and FSA dollars on gym memberships, supplements, and wellness products like Eight Sleep mattresses.

The core mechanism is a regulatory arbitrage play. The IRS defines HSA and FSA funds as eligible for "medical spend" but doesn't restrict that to pharmaceutical products. Truemed exploits that gap by qualifying purchases — gym memberships, Peloton bikes, supplements — as treatments or prevention for chronic conditions like obesity, which clinical research supports. The business is currently 100% e-commerce, but Mares says the a16z capital is earmarked to expand Truemed as a payment option across physical retail and any point of sale where a consumer is spending on health.

The early pushback was predictable: investors questioned whether it was legal, and some weren't convinced that exercise or sleep products constituted legitimate medical interventions. Mares argues the research is clear that lifestyle interventions outperform pharmaceutical ones for many chronic conditions, and the regulatory framework already accommodates that — Truemed is just building the product layer on top of it.

The macro thesis

Mares frames Truemed against what he calls "the Great American poisoning" — roughly $4.5 trillion in annual U.S. healthcare spend, with 90% going toward chronic conditions that he believes are largely driven by a toxic food and chemical environment rather than treated effectively by the existing system. He points to atrazine, the third most popular pesticide in the U.S. and banned in the EU, Canada, and Mexico, as an example of the regulatory gap. The average American's food is, by his estimate, 40 to 70% less nutrient-dense than it was 50 years ago, partly due to soil degradation and partly because produce loses 70 to 90% of its nutrient content across a typical 12-day supply chain.

His investment thesis for the broader health space follows from that: the doctor-patient relationship is being reinvented, pharmaceutical skepticism is rising, and companies like Function and Superpower are building around the idea that meaningful health outcomes happen outside the GP's office. He sees environmental toxins as the defining health trend of the next decade.

Kettle & Fire and the AI efficiency question

On his bone broth company, Kettle & Fire, Mares says AI has already displaced several marketing hires — the company no longer employs a copywriter or full-time designers, roles it held for the first five-plus years. A two-person internal team is now focused on building AI tooling. His framing is competitive: if a CPG company can operationalize AI as effectively as a tech company, it becomes structurally more efficient than any peer. Kettle & Fire is also building a 150,000 square-foot manufacturing facility to meet demand it currently can't fully supply.

Angel investing

Mares invests in roughly 15 companies per year as an angel and holds a venture partner role at Long Journey Ventures. His edge, by his own account, is getting to founders before they've decided to start — writing the first check at seed or pre-seed when valuations can be in the low single-digit millions. His first angel check went into Cusco Energy, now a Founders Fund portfolio company worth billions. His second was into Mind Bloom, an at-home ketamine therapy platform. The pattern is consistent: back people he knows well, move early, and take the pricing advantage that comes from being in the conversation before the round is formed.