My First Million · Episode Brief
$100M founder predicts what will be big in 5 years
Justin Mares makes his five-year predictions about categories that most health-focused founders aren't watching yet, and his track record makes it worth taking seriously.
Justin Mares founded Truemed, a company that helps Americans use HSA and FSA accounts to pay for products that prevent chronic disease, and before that he co-founded Kettle & Fire. He has developed a specific investment and company-building thesis: find the consumer health categories where the scientific consensus is about to shift, build the infrastructure before the shift happens, and wait. This episode is Mares running through five categories he believes fit that pattern.
Longevity products for dogs is the most immediately actionable prediction. The science of lifespan extension in dogs is meaningfully ahead of the science in humans — shorter generation times make experimentation faster. Mares' thesis: the same consumer segment that spends heavily on premium pet food and veterinary care will pay significant premiums for evidence-backed longevity interventions for their dogs. The category doesn't exist yet at scale. It will.
The toxin testing segment is where Mares is most genuinely prescient about where consumer anxiety is heading. Air, water, and food testing have historically been government or industrial functions; Mares argues that the consumer-grade market for personal exposure testing is at the beginning of a years-long growth curve driven by affordable lab-on-chip technology and rising awareness of microplastics, PFAS, and heavy metals. The companies building in this space now are positioning for a market that will be considerably larger in five years.
The doctor-for-your-home concept is Mares' most ambitious idea: a subscription service that performs systematic testing and monitoring of your home's environmental quality (air, water, mold, radon, electromagnetic fields) and coordinates remediation when problems are found. The market is large; the distribution is hard; and the customer acquisition is expensive — but the category is completely uncrowded. The vaccine rant at the end is clearly a sincere expression of his views and will be the most polarizing content in the episode.
Key Ideas
- →Longevity products for dogs represent the leading edge of the human longevity market — same consumer segment, same scientific principles, faster experimental cycles, and almost zero established competition.
- →Consumer-grade toxin testing (PFAS, microplastics, heavy metals in air, water, and food) is at the beginning of a growth curve driven by affordable testing technology and rising awareness of chronic exposure risks.
- →The 'doctor for your home' concept: a subscription monitoring service for home environmental quality (air, water, mold, radon) that coordinates remediation — a large market with no dominant player.
- →Natural fiber clothing as a contrarian health bet: the microplastic shedding from synthetic fabrics is an underreported exposure pathway, and no brand has successfully marketed around this concern at scale.
- →Mares' Truemed business model demonstrates that IRS-recognized medical status for health products can transform consumer willingness to pay — a regulatory arbitrage that the entire preventive health industry is starting to notice.
Worth Remembering
The longevity products for dogs framing — Sam's initial reaction is skepticism, followed by a slow 'oh, this is actually huge' realization as Mares explains the TAM math.
The PFAS testing conversation: Mares casually mentioning that he tests his own blood for chemical exposure regularly, and Sam asking how many of his friends do the same — the answer revealing how early this consumer behavior is.
The vaccine segment, which Mares clearly intended as a substantive discussion and which will have different emotional valence depending on the listener's priors.
Justin's description of how Truemed identified the HSA/FSA arbitrage: a regulatory gap that existed for years before anyone built a company to exploit it, which is Mares' core thesis about where his best ideas come from.