- 5 months ago
Uncover the future of aging with Loyal, the biotech company leading a quiet revolution. Led by founder Celine Halioua, Loyal is unravelling the fundamental mechanisms of pathological aging in our beloved companions.
Their mission? To extend the healthy lives of dogs and, in doing so, reveal unprecedented insights into human longevity.
Loyal joins the 2025 Forbes Next Billion-Dollar Startups list and involves the largest animal clinical trial ever conducted, enrolling 1,300 dogs across 70 veterinary clinics nationwide. The goal: to give dogs "one healthier year" and yield a "gold mine of data" that will fundamentally advance the understanding of aging in both canines and humans.
Could the secret to a longer, healthier human lifespan be found in the journey of our canine companions? Loyal's unofficial slogan hints at the profound answer: "save the dogs, save the world".
Read the full story on Forbes: https://www.forbes.com/sites/amyfeldman/2025/08/11/longer-leash-on-life-inside-the-dog-longevity-startup-loyal/
Subscribe to FORBES: https://www.youtube.com/user/Forbes?sub_confirmation=1
0:00 - Introduction: Can We Delay Aging in Dogs?
0:43 - Our Two Approaches to Longevity
1:15 - The Science: Keeping the 'Engine' Clean
2:05 - Why We Focus on Foundational Biology
2:48 - Inside the Largest Clinical Trial in Animal Health
3:34 - Why We Test on 'Real World' Dogs, Not Just 'Bougie' Ones
4:44 - Overcoming Skepticism in a 'Woo-Woo' Field
5:29 - Meet the Founder: Celine Halioua
6:58 - The Turning Point: From Art Major to a Mission to Prevent Disease
8:16 - The Serendipitous Path to Founding Loyal
10:24 - The 'Eating Glass' Reality of Building a Company
11:32 - Our Breakthrough: Getting the FDA to Recognize Longevity
12:44 - The Investor's 'Aha!' Moment
13:46 - The Ultimate Goal: From Dog Longevity to Human Longevity
Fuel your success with Forbes. Gain unlimited access to premium journalism, including breaking news, groundbreaking in-depth reported stories, daily digests and more. Plus, members get a front-row seat at members-only events with leading thinkers and doers, access to premium video that can help you get ahead, an ad-light experience, early access to select products including NFT drops and more:
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Their mission? To extend the healthy lives of dogs and, in doing so, reveal unprecedented insights into human longevity.
Loyal joins the 2025 Forbes Next Billion-Dollar Startups list and involves the largest animal clinical trial ever conducted, enrolling 1,300 dogs across 70 veterinary clinics nationwide. The goal: to give dogs "one healthier year" and yield a "gold mine of data" that will fundamentally advance the understanding of aging in both canines and humans.
Could the secret to a longer, healthier human lifespan be found in the journey of our canine companions? Loyal's unofficial slogan hints at the profound answer: "save the dogs, save the world".
Read the full story on Forbes: https://www.forbes.com/sites/amyfeldman/2025/08/11/longer-leash-on-life-inside-the-dog-longevity-startup-loyal/
Subscribe to FORBES: https://www.youtube.com/user/Forbes?sub_confirmation=1
0:00 - Introduction: Can We Delay Aging in Dogs?
0:43 - Our Two Approaches to Longevity
1:15 - The Science: Keeping the 'Engine' Clean
2:05 - Why We Focus on Foundational Biology
2:48 - Inside the Largest Clinical Trial in Animal Health
3:34 - Why We Test on 'Real World' Dogs, Not Just 'Bougie' Ones
4:44 - Overcoming Skepticism in a 'Woo-Woo' Field
5:29 - Meet the Founder: Celine Halioua
6:58 - The Turning Point: From Art Major to a Mission to Prevent Disease
8:16 - The Serendipitous Path to Founding Loyal
10:24 - The 'Eating Glass' Reality of Building a Company
11:32 - Our Breakthrough: Getting the FDA to Recognize Longevity
12:44 - The Investor's 'Aha!' Moment
13:46 - The Ultimate Goal: From Dog Longevity to Human Longevity
Fuel your success with Forbes. Gain unlimited access to premium journalism, including breaking news, groundbreaking in-depth reported stories, daily digests and more. Plus, members get a front-row seat at members-only events with leading thinkers and doers, access to premium video that can help you get ahead, an ad-light experience, early access to select products including NFT drops and more:
https://account.forbes.com/membership/?utm_source=youtube&utm_medium=display&utm_campaign=growth_non-sub_paid_subscribe_ytdescript
Stay Connected
Forbes newsletters: https://newsletters.editorial.forbes.com
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Forbes Video on Twitter: http://www.twitter.com/forbes
Forbes Video on Instagram: http://instagram.com/forbes
More From Forbes: http://forbes.com
Forbes covers the intersection of entrepreneurship, wealth, technology, business and lifestyle with a focus on people and success.
Category
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LifestyleTranscript
00:00There's a lot of challenges developing longevity drugs for humans,
00:03predominantly time and money.
00:06But a lot of those challenges are not as severe in dogs.
00:10This is something that people more broadly really want, too.
00:13I kind of thought it was a ridiculous idea for a while,
00:15but then I realized it wasn't.
00:18Loyal is a San Francisco-based startup developing drugs to delay canine aging.
00:23The company, which is one of 25 on this year's Next Billion Dollar Startups list,
00:27has a valuation of $425 million,
00:30and it may have its first beef-flavored longevity pill on the market in 2026.
00:36I learned about the thesis of aging and aging therapeutics,
00:41basically this idea that you can develop drugs that target the mechanisms
00:45by which we deteriorate and age over time
00:48that lead to what we classically consider a disease today,
00:51but are precursors to the disease.
00:53And that's a way to kind of keep somebody healthy longer.
00:56And I was like, well, that just makes a lot of sense.
00:58Like, we should do that, and I want to do that.
01:01We are working on a number of drugs to extend dog lifespan at Loyal.
01:05They tend to fall into two categories.
01:07One category is big dog short lifespan,
01:10so trying to ameliorate the underlying genetic drivers
01:14of why we believe big dogs age faster and die sooner.
01:17And the other category is around metabolic decline,
01:19which is for dogs of any size or most sizes.
01:22You can think of metabolism kind of like the engine of a car, right?
01:27It takes the fuel and turns it into energy and work and makes things happen.
01:31And as the car gets old or as you or your dog get old,
01:34the engine gets gummed up, the oil gets dirty and sticky,
01:38and the spark plugs get all crusty, and it doesn't work as efficiently.
01:41And that leads to a decrease in energy
01:44and to all the diseases that we're used to seeing as people and dogs age.
01:48So the purpose of the drug is to keep the metabolism running
01:52in a healthier, more efficient way, to keep the engine clean
01:55and delay all of those negative health consequences that come with aging.
01:59The broader thesis of the drugs that we've chosen
02:02and the mechanisms we have chosen is, one,
02:05things that are extremely well-validated across organisms, beyond dogs, right?
02:10So these mechanisms or mechanisms have been shown to extend lifespan
02:14in worms and yeast and mice.
02:16This isn't something that's specific to dogs or specific to a breed of dog,
02:20but instead it's just foundational to how organisms have evolved to age
02:26and the ways in which they have evolved to age less healthily or more healthily.
02:30The kind of food you give your dog, the genetic luck that your dog has,
02:33how often you run with your dog or whatever has happened to them in their lives,
02:38that's going to impact their individual aging trajectory.
02:40And so you really have to find a biological mechanism that will not be impacted by all that variability
02:49and instead is much more foundational and fundamental to how life works.
02:53And that's really what we've gone after.
02:55Loyal is now running what may be the largest clinical trial ever conducted in animal health.
03:00It's about 1,300 dogs across the U.S. that are taking either a drug or a placebo,
03:06and it's blinded, so we don't know.
03:07The veterinarians don't know.
03:08Obviously, the dog owner doesn't know.
03:09I guess the dog doesn't know either if they're on the real drug or not.
03:13And we're going to be following these dogs for the next four to five years,
03:16you know, for the rest of their lives to understand how do they age, what diseases do they get,
03:22what are they diagnosed with, you know, what levels in their blood go up or down over time,
03:27to then be able to distinctly quantify at the end, hopefully, a lifespan and healthspan benefit
03:35of the dogs who are treated with our drug over the placebo.
03:38When we started the study, our goal was 1,000 patients, and people said,
03:41you're crazy, you'll never get 1,000 people to enroll in a study like this.
03:44And we've reached 1,300 because there's just an outpouring of enthusiasm.
03:48People are really excited about being part of the study
03:50because they hope that maybe the medication will help their dog,
03:53but also because they want to be part of helping us to develop something new
03:57that will help other people's dogs in the future.
03:59We actually very intentionally are not doing centralized trials.
04:02We're doing decentralized trials.
04:03We want to capture the breadth of diversity that you have in the average dog, right?
04:10We don't just want Silicon Valley, you know, super bougie dogs on $500 dog food.
04:15We don't just want, you know, pure reads or just working dogs.
04:19We want the dog that sleeps on the couch all day and the dog that runs a marathon with its owner.
04:23We want the dog that's purebred.
04:24We want the mud that somebody rescued from the shelter.
04:26And we are doing that in part by ensuring we have a huge geographic
04:31and socioeconomic diversity in the vet clinics that we have chosen,
04:35so that we're able to capture that variability and adequately assess the benefit
04:42of our longevity drugs on that diversity.
04:45And that's really important when you're looking at something like aging,
04:48because aging is extremely complicated and you need to be able to tease that out.
04:53We're going to get an incredible goldmine of data about how dogs age,
04:56about the diseases they get, the causes of those things.
04:59And I think that's really going to advance the field of geriatrics in veterinary medicine.
05:03We're going to help other researchers and veterinarians to take better care of senior
05:07dogs even beyond the drugs that we're developing.
05:11Part of the reason that I encounter skepticism when I talk to people about
05:14extending lifespan in dogs is that the field of longevity research is pretty well known.
05:19And unfortunately, there's a lot of not very scientifically legitimate stuff
05:23being talked about out there.
05:25And it's sometimes hard to distinguish really good science from sort of fake science
05:29or marketing of new ideas that aren't really legitimate.
05:32There are always a few skeptics who say,
05:34well, gosh, aging is not something we can do anything about.
05:36It's just sort of an inevitable part of the universe.
05:38But when we explain a little bit about how it works and how we already know from research
05:43science that you can extend lifespan and delay all of the diseases of aging,
05:47then that skepticism often turns to excitement.
05:49I think my non-canonical upbringing was crucial because I was exposed pretty young
05:57to the vulnerability that the average American and average person more broadly has to health
06:05and to health scares.
06:06I think, you know, now in the world that we're in, you know, here in Silicon Valley,
06:09people have concierge doctors and their employers pay for super platinum healthcare insurance.
06:14That wasn't how I was raised.
06:15And so it really made me respect and be cognizant of the lack of free will that we have
06:22from disease and sickness.
06:24And it solidified my desire to do something about it.
06:29When I started Loyal five years ago, most biotech people who I talked to,
06:36when I told them I wanted to get a drug FDA approved for lifespan extension,
06:40they were like, good luck.
06:43That is never going to happen.
06:45That's not how it works.
06:46You know, naive little girl, like, go have your first meeting and you'll see what happens to you,
06:51basically.
06:52And, you know, they were wrong.
06:54Loyal's 30-year-old CEO, Celine Halliwa, is a scientist who loves animals.
07:01My family are huge animal lovers to the point that after it would rain,
07:06we'd walk around the block and pick up the snails so they wouldn't get run over by cars
07:11or stepped on by people on the sidewalk.
07:13We had 15 cats, four dogs, rescue squirrels, the whole thing.
07:18I wanted to be a veterinarian when I was a kid.
07:21I have a 10, 11, 12-ish-year-old Rottweiler named Della,
07:26who I adopt from a senior dog rescue called Muttville here in San Francisco.
07:30She is the light of my life.
07:31She is the sweetest sweetie pie.
07:34She enrolled at the University of Texas at Austin as an art major,
07:38but soon found herself spending hours in the lab.
07:41Pretty quickly after I started at UT Austin, I wanted to go work in a lab because I was really
07:46interested at the frontier of science, not just catching up on where the science is,
07:49but can we really find the edge of the bubble and help start pushing it forward.
07:55I had always been very interested in seeing the inside of the body, MRIs, CAT scans,
07:59things like that that allow you to see the structure, especially the structure of the
08:03brain is something I've always been very interested in.
08:05And I decided to do a shadowing at a neuro-oncology clinic that was MRI-based.
08:12I met people who were being told by the physician I was shadowing that there was
08:16nothing that they could do and that they were going to die.
08:18That kind of prognosis didn't sit well with her.
08:21Why aren't we working on preventing somebody from getting this disease, right?
08:25Why is the only amount of work on the end stage or the majority on the end stage of the disease
08:30and not the precursors of the disease that often developed decades before,
08:34which is the case for a lot of these age-related diseases.
08:37So she turned to research.
08:39There's many ways to help people.
08:40You can become a nurse, you can become a firefighter, you can become a doctor.
08:43But there was also this whole other world that I didn't really understand at the time,
08:47which was developing and translating new medicines, which wasn't necessarily most
08:55facilitated by being a doctor.
08:57Or certainly being a doctor was not the only path by which to do that.
09:00After undergrad, Celine went to Oxford to work on a PhD in the health economics of gene therapy.
09:06Europe is well known for having these single payer healthcare systems where they invest a lot
09:12in preventative care. And I thought it would be interesting to live in and work in an environment
09:18and work on medicines in an environment where that economic incentivization of the kind of medicines
09:23I was going to develop or wanted to develop existed.
09:26While I was at Oxford, I became pretty convicted in that, you know,
09:30the way I was going to have my impact on the world was developing drugs for aging,
09:33whether it was facilitating or developing them myself.
09:36While still pursuing her PhD, Celine joined the Longevity Fund,
09:40a venture capital firm based in San Francisco, after reaching out to founder Laura Deming.
09:45And I sent her a cold email and asked if I could shadow her for two weeks over winter break
09:52and learn a little bit more about what she was doing and learn a little bit more
09:55about this world where people, you know, invest in companies that have a 99% probability of failure
10:02with the hope of them becoming, you know, something that has a huge impact on the world.
10:07The first thing I learned is I'm not a very good venture capitalist.
10:11And I am not particularly interested in being a venture capitalist.
10:15But that's okay, because I did find out that I really like operating.
10:18And I really like making things happen.
10:20And the insights that led to Loyal and to Dog Longevity, I never intended to start this company.
10:27It really kind of happened serendipitously.
10:29It came from a combination of, you know, all these companies that come pitch us at Longevity Fund.
10:34And I just didn't understand why nobody was developing an aging drug for aging and longevity.
10:40And so I became obsessed and I worked for, you know, almost two years with Laura with how could
10:44you get the first drug FDA approved for lifespan extension?
10:46I was trying to find someone who was working on dog cloning.
10:52And someone said, oh, you should go talk to Celine.
10:54She's, you know, a PhD student at Oxford and is super smart and doing a bunch of work.
11:00Maybe she knows something there.
11:02And I got connected.
11:04I met her.
11:05And in that very first meeting, she said, look, that's a cool idea.
11:09I know nothing about dog cloning.
11:11But like now that you prompted me on dog cloning, I'm studying longevity.
11:16What about dog longevity?
11:17Like if we can't clone the dog, you know, how about how about making the dog live longer?
11:21When you say I want to develop a human longevity drug, there becomes a lot of questions, right?
11:26When you talk about dog longevity, everyone's like, oh, well, yeah, obviously dogs deserve
11:30a little longer, healthier life.
11:32Obviously, they should not get sick.
11:34And I thought it was a really nice way to introduce the thesis to the average person
11:38who may never have heard of it before or may only have negative connotations and really show
11:42that the science is legitimate.
11:43Greg Rosen, he had been one of the early investors in Roe.
11:46And so he'd seen kind of this intersection of pharmaceuticals and consumer branding
11:50and what can happen when you have that direct relationship.
11:53And so he convinced me that it was a good idea from a company's perspective.
11:56And he convinced me that I could be a founder and a CEO.
11:59It's like my job to meet early, you know, founders and people all day.
12:04There are certain people that you meet that just like jump off the page
12:08and sort of cut through the noise.
12:09You're like, whoa, I don't even know what that was.
12:11That was exciting.
12:12That was exactly how I felt with Celine.
12:15I think the most accurate description I've ever heard of building a company is like eating glass.
12:20And it really is like eating glass or like running towards the fire, right?
12:23Like every time there's a fire, there's no one else going to put it out,
12:26especially in the early days.
12:27Ultimately, there was nothing other than her to start and a dream.
12:33And maybe like a little bit of data.
12:35But really, it was a lot of narrative and storytelling to convince early investors
12:41who also really weren't scientists as well.
12:43The seed was just me and a pitch deck.
12:45So it was really when I closed that seed round in January 2020, when we were off to the races,
12:50this thing existed in the real world.
12:51We had some money.
12:52The first years were really figuring out who we wanted to be when we grew up, right?
12:57We had this broad thesis.
12:58And I knew I always set the expectation that the end goal was to get the first drug FDA approved
13:03for lifespan extension in dogs.
13:05And once I started hiring and building the team, we started iterating on that
13:09and led to some of the drugs that we have today, which I never would have come up in my wildest dreams,
13:14or much more effective ways of getting at the biology and the core thesis of the company.
13:22And then also a lot of figuring out the complexities of developing a drug.
13:27It's not just like putting something in a pill and like calling it a day.
13:30It is every aspect of it is extremely regulated and extremely difficult.
13:34And it takes an extremely long time.
13:36If you want to do it in a period of time that's reasonable, you have to be on it.
13:40This ain't no software app.
13:43We have a real commitment to doing the science well and effectively.
13:47You know, we've gone through the FDA approval process for our drugs rather than making,
13:51you know, a supplement or a diet because it's a higher evidence bar.
13:54It's more work.
13:55It takes longer.
13:56But at the end of the day, you have something that you can have more confidence in
14:00that is truly safe and effective and works.
14:02I wanted to show that we're not just developing a supplement with sexy marketing or whatever.
14:07Cool. Great.
14:08I wanted to show that we could get a drug through one of the toughest and most well-respected
14:13regulatory bodies in the world through the FDA for lifespan extension.
14:17And it showed that this is a legitimate, you know, field of science just like anything else.
14:20And we could do that in dogs.
14:22We, you know, got the FDA to agree that a drug can be approved for lifespan extension,
14:27health span extension.
14:28The first time that's occurred as far as we know in any species.
14:30And then we followed up by getting the efficacy approval for twice now for two of our drugs have
14:39earned a reasonable explanation of efficacy, which basically means that the agency has
14:44assessed our thousands of pages of data and believes it's reasonable to expect that these
14:49drugs are going to extend the healthy lifespan of a dog.
14:52It also means that we're getting closer and closer of bringing this to market.
14:56So we still need a few more FDA approvals.
14:58Again, every step is extremely regulated to be able to bring a drug to market.
15:03But we are closer than anybody else ever has been.
15:07I always ask myself when I'm meeting someone and in hearing about their company, how can
15:12this be the most important company over the next decade?
15:15And I, I wasn't even connecting the dots that like a dog longevity business can actually
15:21potentially become the longevity business.
15:24And you only earn the right to do that through building a really big first act business.
15:29And, uh, and, and that's like a classic example of Celine, just like up-leveling sort of
15:34what I thought was an ambitious idea to something even, even better.
15:38A lot of people don't get it.
15:39But for those who do, they get it so deeply in their soul and it matters so much to them personally.
15:45And yes, obviously investors want to make money and they have, you know, responsibilities to their
15:50investors, but people just care personally about this in a way that it is difficult to care as much
15:56about, you know, a B2B SaaS company or whatever it is.
16:00And I think that's really been a tailwind for us.
16:02Loyola has raised about 150 million to date, um, from excellent investors.
16:07And I think the reason we have been successful in raising capital is because we're building a
16:12future that people want fundamentally, and we're making progress on it.
16:17And we're making impressive progress on it.
16:19If I may say that five years ago, when I started this company, I think 90% of people passed.
16:25Most people didn't believe that we would get anywhere.
16:27Most people didn't believe that this was something that should be built.
16:30And so I don't take for granted the fact that, you know, we have made so much progress that it is,
16:37evident to an independent third party that we could be worth billions of dollars one day.
16:41I live in San Francisco, which is obviously the epicenter of AI and innovation that's happening.
16:48And yet when I mention or loyal or dog longevity comes up or loyal comes up,
16:56everyone's eyes light up and it doesn't matter what they're working on, what cool company they're at.
17:01They, the whole conversation shifts to like, Oh, tell me more about that.
17:05Um, especially if someone already has a pet or a dog and, and that's fun.
17:11It's like refreshing. It cuts through the noise and some, uh, in a lot of areas.
17:14And, uh, that's what makes it so fun and exciting to work on.
17:19My ambitions for longevity do not end with dogs.
17:22I think developing drugs to extend dog lifespan is one of the best ways to develop drugs to extend
17:27human lifespan.
17:28The things that we'll learn from developing our drug that hopefully gives dogs more
17:32healthier years is going to teach us so much about how we as humans, you know,
17:36we as their protectors who live with them, who share the same environment,
17:40who get the same disease as they do, who are exposed to the same things that they are.
17:44You know, if we can help a dog live a longer life,
17:47it's going to help us understand what can make a human live a longer and healthier life too.
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