Stem Cells, Skin Longevity, and Why I'm Equally Excited and Skeptical
Hillary Lin, MD·
My November 2025 conference notes on regenerative therapies, skin care, seafood, and Mimio, with the evidence and questions behind each.
Hi there,
Where is longevity headed? We've been hearing about 100+ biomarkers, peptides, and hormones, but is that what's really around the corner?
I just got back from three days at Eudemonia in Palm Beach, and I have thoughts. Today I'll share the topic I'm most excited about in longevity right now, plus the one I'd tell you not to spend money on yet.
I came home with plenty of questions. Also fish.
At Eudemonia, I had the chance to catch up with dozens of friends - movers and shakers in the longevity space - from all over the country!
The topic I’m most excited about also makes me skeptical
Regenerative medicine aims to repair or replace damaged cells and tissues. Some uses already help patients; many treatments sold for general rejuvenation remain unproven.
Stem cells can develop into other cell types. Exosomes are small particles that cells release, carrying proteins and other material. Knowing what these particles do in a laboratory does not show that a commercial treatment is effective or safe.
Here's what I found:
Most companies had compelling mechanism data ("this activates X pathway!") but thin outcome data ("...and in 47 patients over 3 months, inflammation markers dropped by..."). The industry is racing ahead of evidence. Which, honestly, isn't new in longevity 😅
My take? This is worth watching closely. Some of it will probably work. But we're not there yet on knowing which therapies, for which conditions, at what dose, with what safety profile over what timeline.
If someone's pitching you stem cell treatments, ask these questions:
What clinical outcomes have you measured, beyond a marker change?
How long have you followed patients, and what adverse effects occurred?
Who should not receive this treatment?
Where do the cells or particles come from, and how do you test and process them?
What regulatory authorization permits this specific use? A trial listing or facility registration is not product approval.
At these prices, I’d wait. I want better outcome and safety data before spending a large sum on general rejuvenation.
An unplanned detour into skin longevity
There was an actual MRI truck at the conference! Also a mysteriously tasty sparkling protein drink using (thankfully) monk fruit and not artificial sweeteners. Also, that's me having fun at the OneSkin station.
Confession: I tried every skin longevity product on the expo floor. Young Goose and OneSkin were the primary exhibitors.
But I didn't buy anything at the conference.
Instead, Instead, I went home and read for several hours. The mechanisms interested me, but many newer products have less clinical evidence than established ingredients.
Your skin shows some visible effects of aging and sun exposure. Its appearance does not reliably tell us how long you will live, but it is a tissue we can care for directly.
A topical product avoids some risks of a systemic drug, but formulation, skin penetration, irritation, and the measured outcome still matter.
What the skin-aging evidence supports
Sunscreen:A randomized trial found less skin aging with daily sunscreen than with discretionary use. Preventing UV damage is a sound place to start.
Retinoids: These can improve signs of photoaging, but irritation is common and the evidence differs by molecule and formulation.
Vitamin C, alpha hydroxy acids, and niacinamide: They have plausible mechanisms and clinical studies for selected skin outcomes. Their effects depend on dose, formulation, and the problem you are treating.
Peptides: Some have encouraging laboratory and early clinical results. Those findings do not establish that every peptide serum reaches the skin layer it targets or improves visible aging.
Forty-seven ingredients in a serum won’t tell me whether it works. I want studies of the actual product, with useful outcomes and a comparison group.
For products meant to act below the skin surface, I also want evidence that the ingredient reaches its target. OneSkin showed me absorption data at the conference; that alone does not settle its clinical benefits.
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Two things made it from the expo floor to my credit card:
Seatopia - Not supplements. Not peptides. Seafood.
Seatopia says it tests seafood for microplastics, mercury, and omega-3 content. I found the testing approach appealing, along with its claims about feed and farming conditions. I would read the report for the batch I receive: “not detected” means below that test’s detection limit, not proof that no particles are present.
Fish can fit a healthful diet. Observational links between omega-3 measures and health outcomes are interesting, but they do not prove that this seafood brand improves cognition or extends life.
I’m still puzzled by the plastic packaging: how do the batch tests account for packaging and storage? I still want to understand that better.
Mimio was the supplement I bought to explore the idea of mimicking some fasting-related signals.
I’ve tried prolonged fasting. I lost fat. But the hunger (and hair loss)? Not worth it for me. I can report those effects; I can’t tell from my experience what happened to autophagy.
Mimio combines spermidine, nicotinamide, PEA, and OEA. The company built it around metabolites associated with fasting. A small randomized trial published in 2026 reported changes in hunger and cardiometabolic markers after eight weeks. It did not test lifespan or show that a pill reproduces all the effects of fasting.
When I wrote this issue in November 2025, I planned to try it for a few months and report back. Results in model organisms helped explain my interest, but they cannot predict a human lifespan benefit.
Going to a longevity conference and coming home with fish feels very on-brand.
All the goodies I came home with and am digging into, longevity nerd that I am!
Wellness and longevity just merged
I used to separate these cleanly: wellness was non-clinical stuff (meditation, supplements, biohacking gadgets), longevity was medical interventions (GLP-1s, hormone therapy, prescription protocols).
After Eudemonia, I'm retiring that framework entirely.
New model: "Healthcare you actually want" versus everything else.
Healthcare you want = stuff you're excited to engage with. Makes you feel better, perform better, look better. Could require a prescription or not. Turns out people don't care about that distinction. They care whether it works and whether engaging with it feels like self-optimization rather than disease management.
Everything else = healthcare you'd rather not think about. The colonoscopies and chronic disease management we do because we have to, not because we want to.
This might sound like semantics but it's a massive shift in how we should be building companies in this space.
The companies that understood this at Eudemonia? Their products felt like luxury goods, not medicine. Messaging was aspirational, not fear-based. They got that the future of longevity isn't scaring people into healthspan. It's making healthspan something people actually want to pursue.
This is where wellness and longevity converge. It's probably where the money is too.
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In 10,893 older Australian adults, frequent music listening was associated with lower dementia risk. This was an observational study, so health, education, and other differences may help explain the result. Enjoying music is worthwhile; this study does not put it on the same evidence level as exercise.
🗣️ Multilingualism linked to a survey-based aging measure
A study across 27 European countries used health, function, and cognition data to estimate age gaps. Multilingualism at the country level was associated with less accelerated aging in that model. It doesn’t prove that starting a language course slows an individual’s aging. The paper received an author correction in October 2026.
🧬 T cells and senescent-cell control
Researchers studied CD4 T cells expressing Eomesodermin in aging and tissue senescence. Removing these cells in mice worsened senescent-cell accumulation and health. That supports a biological role worth studying, not a ready treatment to slow human aging.
⚠️ High Tyrosine Levels Linked to Shorter Lifespan in Men
A cohort and genetic analysis linked higher tyrosine to shorter lifespan, with results that varied by sex and statistical method. The adjusted estimate reported for men was roughly one year, not two to five. Genetic estimates of circulating tyrosine do not show that eating more protein shortens life.
📊 Calorie restriction and rapamycin: animal evidence
Animal experiments have made calorie restriction and rapamycin important tools in aging research. The linked Nature article is a news feature, not the meta-analysis itself. These results do not establish either intervention as a way for healthy people to live longer.
Events listed when this issue was published
👂 Molecular You Webinar – Dec 3, Virtual. This is geared toward clinicians but anyone can join! We'll be discussing precision longevity.
🚀 The Longevity Global Summit 2025 – Dec 9-10, Novato, CA. Clinical Panel. I’m so excited to speak at the Buck Institute with the movers and shakers of longevity! Code SUMMITSPEAKER15 for 15% off
🎉 A4M Longevity Fest – Dec 12-14, Las Vegas, NV. This is oriented toward practitioners in longevity, with more clinical talks and exhibits. Betting we'll learn a ton here!
The Livelong Women’s Health Summit was listed for April 17–18, 2026, in San Francisco. I was scheduled to speak on women’s longevity.
Offers listed in November 2025
This issue included an affiliate offer from NeuroAgeTx. I may earn a commission from qualifying purchases. Check current services and prices before buying.
This issue also included a Timeline offer with code CARECORE. Urolithin A has human research on selected muscle and mitochondrial measures; that is not proof of longer life. Check current offer terms.
What I'm thinking about this week
More peptides, more exosomes, more AI aging clocks. We’re still sorting out which ones improve health and which only change a measurement.
The people doing real work in this space aren't the ones making the biggest claims. They're the ones asking the hardest questions.
I want to hear from you: I learned way more at Eudemonia than I could fit in one newsletter: women's health protocols, peptide deep dives, what's actually happening with biological age testing, and more.
What do you want me to dig into next? And what are you most excited about, or skeptical of, in longevity medicine right now? Hit reply – I read every message!
