Pet longevity drugs: which startup is ahead?

Pet longevity drugs: which startup is ahead? Last updated: 31 July 2026 In our Pet Tech market deck , you will find everything you need to understand the market SUMMARY Loyal is clearly ahead in pet longevity drugs, and the gap is wide. It is the only startup with a broad canine longevity medicine close enough to FDA conditional approval for a near-term veterinary launch to look realistic. The lead is regulatory before it is financial. Loyal has completed the preliminary-effectiveness and target-animal-safety sections for LOY-002, leaving manufacturing as the last major technical requirement disclosed for possible conditional approval. Loyal has also built an operating advantage that will be hard to copy quickly. Its STAY study enrolled about 1,300 senior dogs through veterinary practices across the United States, giving the company a much larger clinical and veterinary network than any startup rival. That scale still does not prove lifespan extension. No company in this comparison has shown that its product makes dogs live longer, and Loyal has not released completed survival results from STAY. Animal Bioscience is the only core startup visibly making product sales today. Leap Years can already be bought by ordinary dog owners, although that commercial head start comes from taking the supplement route rather than completing the regulatory work required for a prescription drug. Leap Years has better evidence than the average pet supplement, but the result is narrower than the marketing category suggests. Its randomized study found an improvement in owner-assessed cognition over three months, while most objective measures did not show a significant advantage. Rejuvenate Bio is the strongest therapeutic challenger because it offers a genuinely different model: one-time gene therapies for chronic diseases that shorten older dogs’ lives. Its partnerships with Phibro, Merck Animal Health and another established animal-health company make it more credible than its funding total alone would suggest. Rejuvenate Bio may also have an easier initial sales story than a general longevity pill. Treating a diagnosed heart or joint disease gives owners and veterinarians a visible medical problem, even if the company is not yet addressing aging across the whole canine population. Epiterna is a serious discovery company, but it is not yet a serious product competitor. Its small-molecule strategy could eventually be cheaper and simpler than gene therapy, but the company has not publicly identified a lead canine drug, trial design or regulatory path. The category is still almost entirely about dogs. None of the four startups has advanced a cat longevity program to a comparable stage, leaving feline aging as the clearest open market rather than a crowded extension of the current race. Loyal could still lose its lead through manufacturing delays, weak long-term results or poor adoption by veterinarians and owners. Right now, though, the ranking is not close: Loyal leads prescription longevity, Rejuvenate Bio leads longevity-related gene therapy, Animal Bioscience leads supplements, and Epiterna remains the early scientific bet. This market map, featured in our Pet Tech market deck , highlights top companies and startups in the pet tech market Which pet longevity startups are we actually comparing? The serious pet longevity startup race currently comes down to Loyal, Rejuvenate Bio, Animal Bioscience and Epiterna. We are keeping the field narrow. Each company must be developing a product that targets aging itself or a major biological process behind age-related decline in companion animals. That excludes the hundreds of brands selling ordinary joint, cognition or senior-dog supplements with no dedicated longevity research platform. Loyal is developing prescription medicines intended to extend dogs’ healthy lifespan. Rejuvenate Bio uses gene therapy to treat chronic diseases that shorten older dogs’ lives. Animal Bioscience sells Leap Years, a supplement combining an NAD precursor with a senolytic. Epiterna is searching for affordable drugs that could slow aging in dogs. Animal Bioscience belongs in the comparison because Leap Years already competes for the same owners, veterinary attention and healthy-aging budget, although it is sold as a supplement rather than an FDA-regulated drug. We exclude the Dog Aging Project because it is an academic research initiative. Its rapamycin trial could eventually influence the market, but the project is not a startup selling or developing its own commercial product. We also exclude companies such as Gallant, which develops veterinary cell therapies for specific diseases without making pet longevity its central product promise. Despite the broader label, this is currently a dog longevity market. None of the four startups has brought a cat longevity program to a comparable stage. Startup What it is developing Cumulative funding publicly announced or reported Loyal Prescription drugs targeting biological drivers of canine aging More than $250 million Rejuvenate Bio Gene therapies for chronic and age-related diseases in dogs More than$16 million across announced rounds Epiterna Small-molecule interventions intended to slow aging in dogs €10 million Animal Bioscience Leap Years, a canine healthy-aging supplement Not publicly disclosed; one private-company database estimates about $1.7 million Is Loyal already the clear leader in dog longevity drugs? Loyal is comfortably ahead in dog longevity drugs, with no close second place. The clearest evidence comes from the regulatory race. Loyal’s lead product, LOY-002, has completed two of the three major technical requirements needed for possible FDA conditional approval. The FDA has accepted the sections covering preliminary effectiveness and target-animal safety. Manufacturing remains unfinished. No other pet longevity startup has disclosed comparable FDA progress for a product aimed at extending healthy lifespan across a broad population of dogs. Loyal also has a much larger clinical operation. Its placebo-controlled STAY study enrolled about 1,300 senior dogs through dozens of veterinary practices. The nearest published startup trial involved 70 dogs, while Rejuvenate Bio’s first disclosed canine gene-therapy study treated 17. Funding widens the gap further. Loyal announced a$100 million Series C in February 2026, taking its total above $250 million. Rejuvenate Bio has announced more than$16 million in cumulative financing, while Epiterna has disclosed €10 million. The money alone would not make Loyal the leader. What separates the company is what that money has already produced: an advanced regulatory application, a nationwide clinical study, several drug programs and preparations for a commercial launch. Rejuvenate Bio has become a more credible challenger lately, especially after bringing Merck Animal Health into a new research collaboration. Even so, Loyal remains several development stages ahead. If you want more recent data on this point, please see our latest Pet Tech market report . As this chart shows, and as featured in our Pet Tech market deck , search interest in pet cameras has risen sharply Which dog longevity drug could reach veterinary clinics first? LOY-002 is the only dog longevity drug currently close enough to approval for a near-term veterinary launch to look realistic. Loyal is developing LOY-002 as a daily prescription pill for dogs aged at least 10 and weighing at least 14 pounds. The drug targets metabolic dysfunction associated with aging and is intended to extend healthy lifespan rather than treat one diagnosed disease. The FDA’s expanded conditional approval route requires full safety and manufacturing packages, plus a reasonable expectation that the drug will work. It does not require the same level of effectiveness evidence demanded for full approval at the moment of launch. A company can sell a conditionally approved drug while completing the longer study needed to prove substantial effectiveness, subject to annual renewals for up to five years. Loyal has cleared the safety and preliminary-effectiveness parts. Manufacturing quality is the remaining major technical section. An accepted manufacturing package would still not guarantee approval, but it would leave Loyal much closer to market than any startup rival. Rejuvenate Bio has discussed pursuing regulatory approval for its canine gene therapies, yet it has not announced an accepted FDA technical section. Epiterna has not disclosed a clinical candidate. Leap Years is already sold, although owners can buy it because it is regulated as a supplement rather than a prescription longevity drug. LOY-002 could therefore become the first product that lets veterinarians prescribe a medicine specifically intended to lengthen dogs’ healthy lives. For now, Loyal has no visible competitor approaching that same point. Which pet longevity startup has the strongest scientific evidence? No pet longevity startup has proved that its product extends dogs’ lives, but Loyal currently has the strongest regulatory case and Animal Bioscience has the clearest published clinical results. Those two forms of evidence answer different questions. The FDA’s acceptance of Loyal’s preliminary-effectiveness section means the agency found a reasonable basis to expect LOY-002 to work. It does not show how much longer treated dogs will live, and Loyal has not publicly released completed survival results from STAY. Animal Bioscience has published more detail. A randomized, double-blind and placebo-controlled study conducted at North Carolina State University enrolled 70 senior dogs with mild or moderate cognitive impairment. Fifty-nine were included at the primary three-month endpoint. Dogs receiving the full dose showed the largest improvement in owner-assessed cognitive scores, with a statistically significant difference across the three treatment groups. However, activity monitors, clinic-based cognitive tests, gait speed and most other outcomes showed no significant advantage over placebo. The cognitive improvement also stopped widening between months three and six. The study supports a fairly narrow conclusion: Leap Years may improve owner-observed cognition over three months. It does not demonstrate slower biological aging or longer survival. Rejuvenate Bio’s evidence is more experimental. The company reported durable biological activity and encouraging disease-progression data from a 17-dog mitral-valve-disease study. The trial lacked a randomized concurrent control group and relied partly on comparisons with historical disease progression, which makes the apparent benefit harder to measure confidently. Epiterna has not released comparable results in dogs. Loyal has put together the broadest evidence package and the largest trial. Animal Bioscience has given the public the most transparent completed startup study. The decisive lifespan evidence remains missing across the whole field. Startup Best evidence available What we can reasonably conclude What remains unproved Loyal FDA acceptance of preliminary effectiveness and safety sections; large STAY study underway LOY-002 has a credible biological and regulatory case A measurable extension of healthy lifespan Animal Bioscience Randomized, blinded and placebo-controlled senior-dog study The full dose improved owner-assessed cognition over three months Longer life or broad objective improvements Rejuvenate Bio Small canine gene-therapy study and preclinical programs The therapy can produce durable biological activity and may slow one cardiac disease Benefit in a large randomized dog population Epiterna Screening and preclinical research platform The scientific strategy is plausible A working canine product or clinical result This chart, included in our Pet Tech market deck , shows annual VC investment in pet tech startups Is Leap Years a real rival to dog longevity drugs? Leap Years is currently the strongest commercial pet longevity supplement, but it cannot make the same claim as a successful prescription longevity drug. Owners can already order the product in the United States without visiting a veterinarian. Animal Bioscience offers it as a monthly chewable system, with one component taken daily and another given on two consecutive days each month. The formulation combines an NAD precursor with a compound intended to reduce senescent cells. That convenience gives Animal Bioscience an early advantage. The company is already learning whether owners can follow the routine, whether dogs will keep eating the chews and whether customers renew their subscriptions. Loyal will face similar questions when it asks owners to give healthy senior dogs a prescription pill every day. Leap Years also has better evidence than the average pet supplement. Its North Carolina State University trial was randomized, blinded and placebo-controlled, and the results appeared in Scientific Reports. The improvement was concentrated in an owner questionnaire, while objective measures remained largely unchanged. The company’s marketing sometimes travels further than the published data. Claims about improving healthspan or addressing aging at its source are much broader than the trial’s demonstrated result. There is no evidence that Leap Years makes dogs live longer. Commercially, Animal Bioscience appears active but still small. Its store offers subscriptions, single purchases and multiple weight-based doses. It also currently uses stock-notification pages for some large-dog sizes, showing that it is managing real inventory rather than merely collecting reservations. Revenue, subscriber numbers and customer retention remain undisclosed. Leap Years deserves attention because it has a product, customers and a peer-reviewed trial. Its position is closer to “best-evidenced longevity supplement” than “second-most-advanced longevity drug.” If you want more recent data on this point, please see our latest Pet Tech market report . Can Rejuvenate Bio’s one-shot gene therapy overtake Loyal’s pills? Rejuvenate Bio has the most credible alternative to Loyal’s daily-pill strategy, although its current programs target individual diseases rather than aging across the whole dog population. The company’s original canine program uses gene therapy against myxomatous mitral valve disease, a common and serious heart condition in older dogs. Rejuvenate Bio reported treating 17 dogs and observing biological activity lasting more than two years in several cases. Among 12 treated Cavalier King Charles Spaniels, the company said disease progression occurred more than 18 months later than expected from published historical data. That result deserves further testing, but a small study without a randomized concurrent control cannot tell us how much of the difference came from the treatment. A one-time therapy could still be attractive. Owners would avoid administering pills for years, and a durable treatment could justify a higher upfront price. The trade-off is a more complicated product: gene therapies require specialized manufacturing, controlled administration and closer safety monitoring. Rejuvenate Bio has expanded into canine osteoarthritis and other chronic diseases. It also has agreements with Phibro Animal Health and another established animal-health company, giving it commercial support that most early veterinary biotechs lack. Its latest move made the company harder to dismiss. In June 2026, Rejuvenate Bio announced a $6 million financing round that included Merck Animal Health, alongside a new research and development collaboration. Merck is now the third major animal-health relationship attached to the platform. Rejuvenate Bio could build a valuable portfolio of one-dose treatments for diseases that shorten older dogs’ lives. To overtake Loyal in the wider longevity category, it would need larger controlled trials, clear regulatory progress and evidence that its therapies improve more than one disease outcome at a time. This chart, included in our Pet Tech market deck , looks at Tractive’s strategy in pet tech Has Epiterna shown enough to be taken seriously in dog longevity? Epiterna has an interesting dog longevity strategy, but today there is too little public evidence to rank it alongside Loyal or Rejuvenate Bio. The Swiss startup raised €10 million from Prima Materia, the investment company founded by Spotify founder Daniel Ek and early Spotify investor Shakil Khan. Epiterna says it wants to create affordable products that slow aging, delay age-related disease and extend dogs’ lives. Its preference for small-molecule drugs could eventually become an advantage. Pills are generally easier to manufacture, distribute and administer than gene therapies. Epiterna has also explored repurposing compounds with existing pharmacological histories, which could reduce some early discovery risk. The company originally discussed moving from laboratory organisms into larger animals such as dogs. Since then, it has shared little publicly about the step that readers and competitors most need to see. We still do not know which compound Epiterna plans to test first, what type of dog would receive it, what outcome the trial would measure or which regulatory route the company expects to follow. Its current careers page confirms that the team remains focused on products for longer and healthier canine lives, but it does not fill those clinical gaps. At this point, Epiterna looks like a legitimate discovery company with a sensible cost thesis. It has not yet shown that it owns a competitive dog longevity product. Which pet longevity startup is actually making money today? Animal Bioscience is the only core pet longevity startup visibly selling a product to ordinary owners today. Leap Years ships directly to customers in the United States and offers both subscriptions and one-time purchases. The company has therefore reached a commercial stage that Loyal, Rejuvenate Bio and Epiterna have not. We should be careful with the size of that lead. Animal Bioscience does not disclose revenue, order volume, subscriber retention, veterinary-clinic sales or the number of dogs using Leap Years. Product reviews and company-reported administrations confirm usage, but they cannot tell us whether the business has hundreds, thousands or tens of thousands of recurring customers. The product is also easier to launch than a prescription drug. Animal Bioscience did not need to complete the FDA approval process that Loyal is pursuing, and it can advertise general support for cognition, vitality and healthy aging without proving lifespan extension. Loyal remains pre-revenue from its longevity drugs, although a conditional approval could change that quickly. LOY-002’s daily oral format should be relatively simple for clinics and owners compared with gene therapy. The company has not published a final price, so we cannot yet compare its affordability with Leap Years. Rejuvenate Bio may eventually earn partnership payments, licensing revenue or commercial royalties. Its public announcements do not reveal enough contract economics to measure that income. Epiterna has not disclosed any commercial revenue. Animal Bioscience wins the current sales comparison by default. The available evidence still does not show a scaled pet longevity business. This chart, included in our Pet Tech market deck , shows annual funding in pet tech startups Which pet longevity startup has enough funding to finish the job? Loyal is the only pet longevity startup with a financial cushion that clearly matches the cost and uncertainty of late-stage drug development. Its$100 million Series C lifted total announced funding above $250 million. That is more than fifteen times Rejuvenate Bio’s publicly announced cumulative financing and more than twenty times Epiterna’s disclosed round. Loyal will need the money. It must complete manufacturing work, maintain a multi-year clinica