Reversing cellular aging: which startup is ahead?

Which startups are actually competing to reverse cellular aging?

The cellular-aging race currently has eight credible startups, although Life Biosciences, NewLimit and Altos Labs form the only group with both substantial resources and a serious claim to overall leadership.

We define this market narrowly. The companies included here are trying to restore younger cellular behavior through partial epigenetic reprogramming, rejuvenation genes or closely related interventions. They are attempting to change how old cells function, rather than merely measuring biological age or treating one downstream symptom of aging.

Retro Biosciences makes the list because tissue reprogramming remains part of its pipeline, even though its clinical-stage program uses autophagy. Rejuvenate Bio also qualifies because it has published direct partial-reprogramming results in naturally aged mice. Shift Bioscience, YouthBio Therapeutics and clock.bio are much earlier, but each is building a distinct cellular-rejuvenation platform.

We exclude supplement companies, biological-age testing businesses, senolytic developers, plasma treatments, conventional stem-cell clinics and broad longevity holding companies without an identifiable cellular-rejuvenation program.

Turn Biotechnologies would previously have belonged in the comparison. In May 2026, Daewoong Pharmaceutical took over the rights to its mRNA-based ERA reprogramming platform after an asset auction, so Turn is no longer a standalone competitor. The sale is a warning for the field: good science can still run out of money before it reaches patients.

Private-company funding totals vary because databases treat founder commitments, extensions and grants differently. We use disclosed rounds and mark estimates. NewLimit’s total, for example, adds the founders’ original $105 million commitment to its Series A, B, extension and C.

Startup	What it is developing	Funding publicly identified
Life Biosciences	Controlled OSK partial reprogramming, starting with optic-nerve diseases; first human data reported in October 2026	Approximately $230M, including an $80M Series D in April 2026
NewLimit	AI-discovered reprogramming medicines, starting with fatty liver disease	Approximately $755M, including a $435M Series C in June 2026
Altos Labs	Broad cellular rejuvenation and cellular-resilience research	Nearly $6B reported; not confirmed by the company
Retro Biosciences	Autophagy, cell replacement and tissue-reprogramming therapies	At least $180M; May 2026 round at a $1.8B pre-money valuation, amount undisclosed
Rejuvenate Bio	AAV gene therapies, including partial OSK reprogramming	More than $16M in disclosed equity rounds
Shift Bioscience	AI-discovered rejuvenation targets and an siRNA program for liver fibrosis	$18M
YouthBio Therapeutics	Controlled partial reprogramming for Alzheimer’s disease	Undisclosed
clock.bio	Genome-wide discovery of human rejuvenation genes	$5.3M

Is Life Biosciences now clearly ahead of NewLimit?

Yes. Life Biosciences is clearly ahead today, because it now has early human safety data and NewLimit has not yet dosed a patient.

Life’s lead rests on development stage. ER-100 is in an active Phase 1 study in glaucoma and non-arteritic anterior ischemic optic neuropathy (NAION). In October 2026, Life reported its first three patients, and the safety board recommended a higher dose. NewLimit has a liver candidate, scaled production and a Phase 1 in fatty liver disease planned for 2027. Life is at least a year and a full regulatory stage ahead.

Money points the other way. NewLimit has raised roughly 3.3 times as much as Life. Its June 2026 round reportedly valued it at $3.1 billion. Its discovery engine covers liver, immune and vascular cells, while Life’s visible pipeline is still centered on the eye, with an early liver program in mice.

Altos Labs has far more money than either, with The Wall Street Journal reporting total funding near $6 billion. It still has no public lead candidate. Retro has a drug in human testing, but that drug restarts autophagy rather than resetting cellular age.

Life leads clinical translation, and that lead now has data behind it. NewLimit leads discovery speed and funding among the reprogramming specialists. Altos leads financial capacity. Retro leads among the diversified longevity companies.

If you want more recent data on this point, see the latest figures in our Longevity report ↓.

Which cellular-aging startup is closest to proving rejuvenation in humans?

Life Biosciences is the only startup testing partial cellular reprogramming in people, and the only one with human data to show.

ER-100 uses an AAV2 vector to deliver three transcription factors, OCT4, SOX2 and KLF4, to retinal ganglion cells. Life intends the treatment to restore younger patterns of gene activity while allowing the cells to retain their normal identity.

The registered Phase 1 study plans to recruit 18 participants: 12 with open-angle glaucoma and six with NAION. Each participant receives a single dose and undergoes eye examinations, laboratory testing and long-term monitoring. The first six months provide the most intensive observation, while follow-up continues for five years because gene therapies can remain active for a long time.

The trial began in the first quarter of 2026 after FDA clearance. The first three glaucoma patients received the lowest dose, two hundred billion vector genomes, with daily oral doxycycline to switch the genes on. The study’s safety board then recommended moving to a dose three times higher.

NewLimit plans a Phase 1 in fatty liver disease in 2027, with a Phase 2 in alcohol-related liver disease to follow. YouthBio has completed an FDA INTERACT meeting for its Alzheimer’s candidate YB002, which gives early guidance but no permission to dose. Altos has not announced a registered trial, and Retro’s tissue-reprogramming programs remain preclinical.

The gap is simple. Life is preparing to give people a higher dose. NewLimit is finishing the studies it needs to ask for permission. YouthBio is still agreeing on the route toward that request. Everyone else is further back.

Do Life Biosciences’ first ER-100 results prove reprogramming works?

No. Life Biosciences’ first results show that partial reprogramming can be given to a human eye without early harm. They do not prove that it restores vision.

Life presented the data in October 2026. All three glaucoma patients tolerated the lowest dose through day 56, with no dose-limiting toxicity and no serious adverse events. The company linked the side effects it did see to the injection, steroids or existing conditions. Two of the three improved on Humphrey visual-field tests, with at least 28% of test points gaining more than 4 decibels in each.

Those numbers need care. Three patients, 56 days, no placebo group and an open-label design leave room for chance, learning effects and normal test noise. Life itself said efficacy cannot be established from these findings. No NAION patient has been reported yet. The full study plans 18 participants, and any vision gain would need larger controlled trials.

Life’s strongest evidence comes from the research behind ER-100. A Nature study published in 2020 found that OSK treatment helped retinal ganglion cells regenerate damaged axons and restored visual function in aged and glaucomatous mice. The work also linked those improvements to DNA-methylation changes associated with younger cells.

Life later reported related work in non-human primates, which helped support its regulatory package. For now, the company has strong mouse evidence, a clean early safety signal in people and a hint of benefit that the higher dose must confirm.

Which startup has built the fastest cellular-reprogramming discovery engine?

NewLimit currently runs the fastest visible discovery operation in cellular reprogramming, at a scale none of its rivals publicly matches.

NewLimit combines computational predictions with large experiments in old human cells. Its models propose combinations of transcription factors, the laboratory tests those combinations, and the resulting data feed back into the next model. This lets the company search a biological space that would be impossible to explore one combination at a time.

In its 2025 review, NewLimit reported more than 600 payloads that made old cells display younger gene-expression patterns. Thirty-six also restored a youthful cellular function, and 16 improved disease-related outcomes in animal models. The company had progressed one of those payloads into a formal preclinical candidate. These are company-reported operating metrics, not independently verified benchmarks.

During the first two months of 2026, NewLimit reported 50 additional liver-cell payloads, 19 payloads that restored regulatory activity in T cells and a model upgrade that more than doubled discoveries per dollar. A few months later, the company said a generalized model achieved comparable predictions for vascular cells using one-third as much cell-specific data.

A model that transfers lessons between liver, immune and vascular cells could make each new program cheaper to launch. NewLimit still needs outside replication and clinical results, but no rival publicly reports comparable screening scale.

If you want more recent data on this point, see the latest figures in our Longevity report ↓.

Does NewLimit have better cellular-rejuvenation science than Life Biosciences?

Life Biosciences has the stronger evidence package today. NewLimit appears to have the broader platform and the higher long-term ceiling.

Life’s program follows a fairly complete path. Researchers first showed restored visual function in mice, then took the approach through more animal studies, manufacturing, regulatory review, human dosing and a first human readout.

NewLimit has generated far more candidate breadth. Its lead liver payload reportedly helps old liver cells regenerate after injury, resist damage caused by alcohol and recover from harmful diets. The company has observed effects in humanized liver systems and animals, including benefits that lasted after the medicine had cleared from the body. These results carry more weight than a molecular clock alone because they measure whether old tissue performs better.

Life’s core mouse results have appeared in a leading peer-reviewed journal, and its development package has passed through FDA review. NewLimit provides unusually detailed updates, but its decisive liver results still come mainly from the company itself.

Life leads on evidence reliability, and its first human data widen that lead. NewLimit leads on range. It could catch up by publishing the full liver dataset, showing the effect in larger animals and starting its 2027 trial on time.

Does Altos Labs’ huge budget make it the cellular-aging leader?

Altos Labs has the deepest resources in cellular rejuvenation, but Life Biosciences has converted far less money into much more visible clinical progress.

Altos launched with $3 billion in 2022. The Wall Street Journal has since reported that the company raised nearly twice that amount in total; Altos has not confirmed the figure. That would give Altos close to eight times NewLimit’s capital and more than 25 times Life’s.

The company has used that money to recruit leading researchers, build institutes in the United States and the United Kingdom and combine experimental biology with computation. Altos is also developing AI world models that aim to predict how interventions will change cells, tissues and whole organisms before expensive experiments begin.

Its organization has gradually moved closer to drug development. Altos appointed Joan Mannick as chief medical officer and head of product development, a clear sign that the company wants to turn cellular-rejuvenation research into medicines.

The missing piece is still a visible product. As of now, Altos has not named a lead candidate, announced an IND filing or registered a trial comparable with Life’s eye program. It also publishes fewer program-level metrics than NewLimit.

The comparison with Life is stark. Life reached human data with roughly 4% of Altos’ reported capital and about 30% of NewLimit’s. It made a clinical candidate, completed toxicology, won FDA clearance and reported first patient results.

Life benefited from a narrower strategy, licensed academic work and an accessible first organ. NewLimit and Altos are funding broader platforms that could eventually produce several therapies. Even allowing for those differences, Life has removed more product-development risk per dollar.

Rejuvenate Bio also stands out at a smaller scale. With little more than $16 million in disclosed equity funding, it produced a peer-reviewed lifespan study in old mice and secured animal-health partnerships.

Altos may have advanced work behind closed doors, but a competitive ranking has to use observable evidence. For now, its budget creates enormous future options without making it the current leader.

If you want more recent data on this point, see the latest figures in our Longevity report ↓.

Is Retro Biosciences really competing in cellular reprogramming?

Retro Biosciences is one of the strongest longevity startups now, although its direct cellular-reprogramming programs remain secondary to its clinical work in autophagy and cell replacement.

Retro is pursuing several ways to restore function in older people. Its pipeline includes an oral autophagy drug, induced pluripotent stem-cell therapies, protein engineering and tissue reprogramming. This diversified approach reduces the chance that one biological theory determines the fate of the entire company.

Its execution has been fast. Retro says RTR242 moved from indication selection to first-in-human dosing in 15 months. The drug is designed to restart autophagy, the process cells use to remove damaged components, and is being studied as a potential treatment for neurological decline. Retro has also built an internal cGMP cell-therapy manufacturing facility.

Investors rewarded that speed. In May 2026, Retro announced the first close of a round led by 4P Capital at a $1.8 billion pre-money valuation; it did not disclose the amount. No RTR242 results have been made public so far, and Retro’s tissue-reprogramming candidates remain early. Retro belongs just behind the three leaders: its team moves at clinical speed, but its human data, when it comes, will speak to autophagy rather than cellular age.

Which startup has the best animal evidence for reversing cellular aging?

Life Biosciences has the most clinically useful animal evidence, while Rejuvenate Bio has produced the field’s boldest published lifespan result.

Rejuvenate Bio treated 124-week-old male mice with an inducible AAV9 therapy carrying OSK. The study reported a 109% increase in median remaining lifespan and an improvement in frailty.

The treatment did not double lifespan from birth. It roughly doubled the short period these extremely old mice had left, and the experiment involved a modest group of male animals.

Life’s mouse results translate more directly into a drug program. OSK treatment regenerated optic-nerve axons and improved visual function in models of aging and glaucoma. The company could then use a local injection, a defined patient group and measurable eye endpoints to design a clinical trial.

NewLimit has reported that older animals receiving its liver candidate recovered better from injury and behaved more like young animals after alcohol exposure. The full studies have not yet appeared in a peer-reviewed paper.

Rejuvenate leads on published lifespan extension. Life leads on the bridge from animal evidence to human treatment, and that bridge now carries its first human data.

Has Life Biosciences chosen the smartest first organ for cellular reprogramming?

Life Biosciences chose the eye because it offers the safest and most measurable first test of cellular reprogramming, giving the company a real delivery advantage.

Reprogramming treatments must reach the right cells, activate strongly enough to change them and stop before the cells lose their identity. Delivering that level of control throughout the body remains one of the field’s hardest unsolved problems. A Nature Communications review concluded that tissue-specific approaches are more likely to work clinically in the near term because current delivery systems struggle with efficiency and organ specificity.

The eye reduces several of those difficulties. Doctors can inject a small quantity directly into one organ, limiting exposure elsewhere. They can repeatedly examine the retina and optic nerve through imaging, visual-field tests and electrical measurements. The treatment also targets retinal ganglion cells, a defined cell population whose degeneration causes permanent vision loss.

NewLimit has chosen the liver, a larger opportunity with a higher safety burden. Lipid nanoparticles and RNA medicines already tend to accumulate there, but NewLimit will need to control dose, immune response, abnormal growth and off-target delivery across a much larger organ.

The early ER-100 readout shows why the eye was a smart choice: Life could measure visual-field changes in three patients within 56 days. A liver trial will need more patients and longer follow-up to show anything comparable. Life chose the better first clinical target. NewLimit chose the larger platform opportunity.

If you want more recent data on this point, see the latest figures in our Longevity report ↓.

Which cellular-reprogramming startup has the safest approach?

Life Biosciences has the most thoroughly tested safety design today, while Shift Bioscience is developing the clearest alternative to multi-factor reprogramming.

Traditional reprogramming uses OCT4, SOX2, KLF4 and c-MYC. Prolonged or poorly controlled expression can push mature cells toward pluripotency, remove their normal identity and create tumors. The safety challenge is finding enough reprogramming to restore function while stopping well before that dangerous point.

Life removes c-MYC, restricts administration to the eye and controls OSK expression through a doxycycline-sensitive system. Regulators reviewed the company’s manufacturing, toxicology and animal package before allowing ER-100 into Phase 1. The first three patients showed no serious adverse events through day 56, and the safety board recommended a higher dose. That is encouraging, but rare risks such as abnormal cell growth can take years to appear, which is why follow-up lasts five years.

Shift’s earlier SB000 research identified a single gene that lowered molecular-age measurements in fibroblasts and skin cells without activating pluripotency in the reported experiments. Its current lead program, SB101, uses siRNA against a fibrosis pathway and could offer a more familiar, adjustable route than permanent gene delivery. In October 2026, Shift published a Nature Biotechnology study on better ways to test the AI “virtual cell” models it uses to pick targets. Both programs still need independent and in-vivo validation.

NewLimit also uses transient RNA-based payloads and says its liver candidate produced no tumors or liver toxicity in animals even at high doses. The evidence still comes from company reports.

Has any cellular-aging startup found real commercial demand?

No cellular-aging startup has commercial validation yet because the category still has no approved rejuvenation therapy, recurring drug revenue or repeat customer demand.

The strongest evidence available today comes from regulators, pharmaceutical partners and investors willing to fund clinical development.

Life has the clearest regulatory validation. The FDA allowed ER-100 into human testing, and in April 2026 the company closed an $80 million Series D to fund the study and extend its runway into the second half of 2027. Its first patient data now give that clearance some human backing.

NewLimit has the strongest capital-market endorsement. Its $435 million Series C, announced in June 2026, was led by Founders Fund, with Thrive Capital, Greenoaks, Kleiner Perkins and Eli Lilly Ventures. The round reportedly valued it at $3.1 billion, a striking price for a company with no revenue and no patient yet dosed.

Rejuvenate Bio has a more concrete industry link. In June 2026, Merck Animal Health joined its $6 million financing and entered a research collaboration around a veterinary gene-therapy program. That agreement gives Rejuvenate a credible route to collect data in companion animals, although it says little about demand for human cellular rejuvenation.

YouthBio’s FDA INTERACT meeting provides useful guidance for YB002. Retro’s active trial and regulatory interactions validate its development team. Altos’ funding validates the quality of its scientists and ambition.

None of these events shows that patients, hospitals or insurers will pay for cellular rejuvenation. Commercial leadership begins only when a treatment produces enough clinical benefit to justify its price and risk.

Which cellular-aging startup can manufacture at clinical scale?

Life Biosciences has already manufactured a reprogramming therapy suitable for human use, while NewLimit now shows the strongest scaling momentum.

Life had to produce, test and release clinical-grade ER-100 before administering it in Phase 1. AAV products require consistent vector identity, purity, potency and sterility. The small quantity needed for an eye injection makes the program more manageable than a systemic gene therapy, but the manufacturing threshold is still real.

NewLimit started large-scale manufacturing of its first candidate early in 2026. In its latest update, the company reported producing batches more than 120 times larger than before, enough to support pivotal preclinical studies. It explained that discovery experiments require less than one milligram, toxicology studies need more than 100 milligrams and the clinical trial will require over 1,000 milligrams.

The company has also built a potency assay that measures whether each batch produces the intended biological effect in cells. That is important for a reprogramming medicine because checking the amount of RNA or the size of a lipid particle cannot show whether the payload actually rejuvenates its target cell.

Retro has the strongest internal infrastructure outside the two leaders. Its in-house cGMP facility supports cell therapies, and the company has already shown that it can move an oral drug into human testing quickly. Tissue-reprogramming products will still require their own manufacturing process.

Altos can afford virtually any external or internal manufacturing strategy, but its readiness cannot be judged without a disclosed candidate.

Startup	Manufacturing evidence currently visible	Our assessment
Life Biosciences	Clinical-grade AAV2 product released and dosed in Phase 1, with a higher dose recommended	Most validated today, with modest quantities required for eye delivery
NewLimit	More than 120-fold batch scale-up, potency testing and pivotal-study supply	Fastest current scaling progress
Retro Biosciences	Internal cGMP cell-therapy facility and active clinical operations	Strong infrastructure across several modalities
Rejuvenate Bio	Repeated AAV development for animal and research programs	Credible specialist capability
Altos Labs	Vast capital but no disclosed clinical product	Capacity likely available; readiness cannot be measured
Shift, YouthBio and clock.bio	Discovery or early preclinical work	Clinical manufacturing has not been demonstrated

Which cellular-aging startup has the hardest advantage to copy?

NewLimit is building the strongest long-term data advantage, Life Biosciences owns the most valuable clinical head start, and Shift Bioscience has the best chance of disrupting both with a simpler drug.

NewLimit’s discovery loop could become a compounding moat. Every tested payload adds proprietary information about how specific combinations affect old human liver, immune or vascular cells. Better models then guide the next experiments, creating more useful data.

The latest cross-cell results strengthen that argument. NewLimit says its generalized model reached similar vascular-cell performance with three times less cell-specific data. If the effect holds across additional tissues, new programs should need fewer experiments and less money.

Life’s advantage comes from experience that cannot be compressed into a software model. The company has learned how to manufacture ER-100, prepare a regulatory submission, run an ocular gene-therapy study and monitor patients over time.

Shift offers the clearest upset scenario. Its present SB101 strategy uses a single siRNA target rather than a combination of pluripotency factors. A successful single-target drug could simplify delivery, dosing, manufacturing and regulatory review.

Which cellular-aging startup has gained the most momentum lately?

Life Biosciences has made the biggest leaps of 2026: into human testing, then to first human data. NewLimit has moved faster across discovery, manufacturing, hiring and financing.

Life stacked linked milestones through 2026: FDA clearance, trial start, an $80 million Series D in April, patient dosing and, in October, a first readout with a higher dose recommended. Together, they took partial reprogramming from animal experiments to early clinical evidence.

NewLimit’s progress covered more ground. It picked its first candidate earlier than planned, doubled discovery output per dollar with AI, added a vascular program, scaled manufacturing more than 120-fold and, in June 2026, raised $435 million. It is hiring clinical-development and technical-operations staff as it turns from a research lab into a drug developer.

Retro raised money at a $1.8 billion pre-money valuation in May 2026 but has not yet shown trial data. Rejuvenate Bio added Merck Animal Health as investor and research partner in June 2026. Shift sharpened its focus on SB101 for liver fibrosis and, in October 2026, published a study on testing its AI target-discovery models.

Altos keeps building scientific and product-development capacity, yet public disclosures still lack a candidate-level milestone to match Life or NewLimit.

Startup	Most important recent progress	How it affects the race
Life Biosciences	First ER-100 human data in October 2026: no serious adverse events in 3 patients, 2 with visual-field gains, higher dose recommended	Turns Life’s stage lead into the field’s first human evidence
NewLimit	Candidate development, 120-fold manufacturing scale-up and a $435M Series C in June 2026	Makes a 2027 fatty-liver trial credible
Retro Biosciences	May 2026 financing at a $1.8B pre-money valuation; no RTR242 results public	Strengthens Retro as a diversified longevity biotech
Rejuvenate Bio	$6M financing and Merck Animal Health collaboration	Adds a credible veterinary validation route
Shift Bioscience	SB101 for liver fibrosis and an October 2026 publication on its AI target discovery	Provides a clearer path from discovery platform to drug
Altos Labs	Continued hiring in computation and product development	Builds long-term capacity without clarifying clinical timing

What would let NewLimit overtake Life Biosciences?

NewLimit would need a bad turn at Life’s higher dose and a clean trial start of its own in 2027. Another funding round or mouse study will not do it.

The first event is ER-100’s higher-dose cohort. The lowest dose was clean in three patients. If the dose three times higher stays clean and the visual-field gains hold or grow, Life’s lead hardens. Serious inflammation, unexpected cell changes or vector toxicity would weaken Life and could hurt confidence in OSK-based treatments across the field.

The second event is NewLimit’s planned Phase 1 in fatty liver disease. Starting on time in 2027 would close much of the stage gap, especially if its transient RNA medicine avoids permanent gene expression. A delay would expose the distance between fast discovery and the slower work of toxicology, manufacturing and regulation.

A disclosed Altos candidate could also change the ranking quickly. Convincing large-animal evidence or an announced regulatory filing would push Altos into the top group. Strong animal results from Shift could create another route around Yamanaka-factor safety concerns.

Ultimately, efficacy will decide the race. A treatment that safely improves vision, liver function, fibrosis or cognition will move ahead regardless of which company has raised the most money.

Which startups are actually ahead in reversing cellular aging?

Life Biosciences is ahead overall, by a wider margin than before. NewLimit is the only close challenger, and Altos Labs is still the wildcard that has yet to show its hand.

Life holds first place because it has removed the most uncertainty. Its approach restored function in animals, passed manufacturing, toxicology and FDA review, and in October 2026 produced the first human data from a partial-reprogramming therapy: no serious side effects in three patients and early visual-field gains in two. That is not proof of efficacy, but no rival has any human data at all.

NewLimit ranks second by a wide margin over the rest. Its discovery volume, functional liver results, manufacturing scale-up and $435 million Series C show it has moved beyond exploratory research. It could challenge Life if it starts its fatty-liver trial on time in 2027 with a transient, scalable therapy and publishes strong preclinical data.

Altos ranks third because its resources and scientific team remain impossible to dismiss. We place it behind two much smaller companies because the public pipeline is still difficult to evaluate. Capital creates options; it does not show which option can become a medicine.

Retro ranks fourth. Its clinical speed, manufacturing and diversified pipeline make it more mature than most of the field, and investors priced it at $1.8 billion pre-money in May 2026. The gap is category fit: its advanced programs test autophagy and cell replacement more than direct reprogramming, and no trial results are public.

Rejuvenate Bio ranks fifth through its published lifespan experiment and pragmatic animal-health strategy. Shift ranks sixth with a clearer current product path and a potentially safer single-target approach. YouthBio follows because its Alzheimer’s program has received early FDA feedback but faces a difficult brain-delivery problem. clock.bio ranks last because its rejuvenation atlas is interesting discovery work without a defined therapeutic program at comparable maturity.

The gap at the top is real and has grown. Life is a clinical stage ahead and now has data from that stage. NewLimit has more than three times the capital, a broader platform and the fastest operating pace. A clean higher-dose cohort would widen Life’s lead; a smooth NewLimit trial start in 2027 would narrow it, but would still leave NewLimit a year or more behind on human data.

Rank	Startup	Why it ranks here
1	Life Biosciences	Only company with human data: peer-reviewed animal evidence through to a clean first Phase 1 readout
2	NewLimit	Best discovery engine, fastest recent acceleration and a credible near-term clinical candidate
3	Altos Labs	Unmatched capital and scientific depth, with too little visible product evidence
4	Retro Biosciences	Proven clinical-development speed and broad infrastructure, while direct reprogramming remains early
5	Rejuvenate Bio	Strong published mouse result and a practical animal-health development route
6	Shift Bioscience	Differentiated single-target strategy and a clearer liver-fibrosis product path
7	YouthBio Therapeutics	Focused Alzheimer’s program with early regulatory engagement but major delivery risk
8	clock.bio	Large rejuvenation-gene discovery dataset without a mature therapeutic candidate

If you want more recent data on this point, see the latest figures in our Longevity report ↓.