In the world of longevity biotech, some companies neatly fall into familiar categories—working on senolytics to clear aging cells, or epigenetic reprogramming to turn back the clock. But others, like the pioneering startup Junevity, take a less-traveled path. Their mission? To intervene directly in the body’s gene regulation machinery using a precise and powerful tool: short interfering RNA (siRNA).
Backed by a fresh $10 million funding round and a bold scientific vision, Junevity is now focused on two of the world’s most pressing and persistent public health challenges: obesity and type 2 diabetes. These aren’t just conditions of modern lifestyle—they’re metabolic syndromes deeply intertwined with aging, inflammation, and long-term vitality.
At the center of this effort is Dr. Janine Sengstack, Junevity’s co-founder and Chief Scientific Officer. In a candid and illuminating interview, she offers a look inside the science, strategy, and personal passion driving this next-generation therapeutic platform.
A Childhood Calling Turned Scientific Mission
For Dr. Sengstack, the pursuit of healthier, longer lives isn’t abstract—it’s been part of her story since childhood.
“Ever since middle school, I knew I wanted to help people live longer, healthier lives,” she recalls. That early loss of loved ones to chronic diseases propelled her first toward medicine, and later into the world of molecular biology and biotechnology, where she felt she could make an even broader impact.
Today, that vision is focused on treating aging at its roots—not just managing symptoms, but reversing the biological misfires that drive disease from withinindex (9).
Transcriptional Dysregulation: A Common Thread in Aging
Junevity’s scientific foundation rests on a powerful observation: many age-related diseases—including diabetes, obesity, and even neurodegeneration—share a common pattern of gene expression dysfunction.
Rather than targeting one mutated gene (as many traditional drugs do), Junevity looks at broader transcriptional changes—shifts in how genes are turned on or off over time—and aims to reset these patterns to a healthier state.
“We believe transcriptional dysregulation is one of the core issues in complex, aging-related diseases,” says Dr. Sengstack. “Instead of fixing one broken part, we’re restoring balance to the whole system”index (9).
The Power of Silencing: How siRNA Works
The core tool behind Junevity’s platform is short interfering RNA (siRNA)—small, double-stranded RNA molecules designed to precisely “silence” or suppress specific genes. They work by degrading messenger RNA (mRNA) before it can be translated into proteins, effectively turning off the gene at the post-transcriptional level.
Compared to traditional gene editing or overexpression approaches, siRNA offers several key advantages:
- Precision: It targets only the desired sequence.
- Reversibility: It doesn’t permanently alter the genome.
- Durability: Effects can last for weeks or even months.
- Safety: Repression is often safer than adding new factors to cellsindex (9).
“Overexpressing transcription factors can bind off-target and be difficult to dose,” Dr. Sengstack explains. “With siRNA, we’re repressing instead of adding—it’s safer, more controlled, and now well-established in therapeutic development”index (9).
Engineering Long-Lasting, Targeted Therapies
One challenge with RNA-based drugs is ensuring they reach the right tissue and don’t degrade too quickly. Junevity uses a smart delivery method called GalNAc conjugation—attaching a sugar molecule that guides the siRNA directly to liver cells, where many metabolic processes (and diseases) are rooted.
This allows for:
- Organ-specific delivery
- Minimized side effects
- Twice-a-year dosing schedules—a huge leap forward in patient convenience and adherenceindex (9).
Imagine managing a chronic condition like diabetes with just two injections a year. That’s not science fiction—it’s the therapeutic reality Junevity is building toward.
From Lab Bench to Real-World Disease: Obesity and Type 2 Diabetes
Junevity’s current focus is squarely on obesity and type 2 diabetes—conditions that not only sap quality of life but also shorten healthspan and lifespan.
The company’s approach began with large-scale analysis of patient data, including transcriptomic profiles from over 500 individuals with metabolic disease. Using machine learning and computational biology, they identified key transcription factors regulating the gene expression changes seen in these patientsindex (9).
Once a promising target was identified, Junevity developed an siRNA candidate to knock it down in liver cells.
Results?
- Significant improvement in insulin sensitivity, rivaling current medications like pioglitazone
- No associated weight gain, a critical advantage over existing diabetes drugs
- Favorable preclinical safety and metabolic profiles
“In diabetes treatment, improving insulin sensitivity without causing weight gain is a really big deal,” says Sengstack. “Our siRNA candidate shows similar improvements—but with none of the unwanted weight side effects”index (9).
Tackling Obesity: Beyond Appetite Suppression
Obesity drugs have exploded into mainstream awareness, thanks to the success of GLP-1 receptor agonists like semaglutide and tirzepatide. These drugs curb appetite and drive weight loss—but they also come with caveats: muscle loss, nausea, and in some cases, long-term tolerance issues.
Junevity is aiming to go deeper than appetite by targeting the underlying metabolic programming that causes the body to store excess fat.
“Our siRNA approach doesn’t just suppress hunger,” Sengstack notes. “It alters the transcriptional environment in liver cells, rebalancing energy use and potentially avoiding some of the drawbacks of calorie-restriction mimetics”index (9).
The RESET Platform: Rewinding Cellular Age
Junevity’s broader drug discovery engine is called RESET, a platform originally developed during Dr. Sengstack’s doctoral work. RESET uses computational biology and lab-based screening to identify gene regulators that shift older cells back to a younger, healthier state.
But RESET doesn’t seek full reprogramming into stem cells—a risky process that can cause tumors or loss of identity. Instead, it nudges cells partway back, restoring youthful function while preserving identity.
In early studies with fibroblasts (skin cells), RESET restored cellular function even though epigenetic clocks didn’t fully reset. Sengstack interprets this as evidence that functional rejuvenation is possible without complete reversion—a safer and potentially more practical approachindex (9).
Why Target Aging Through Metabolic Disease?
While many longevity companies chase interventions that directly reverse aging biomarkers, Junevity’s strategy is refreshingly grounded: tackle diseases of aging with clear clinical endpoints.
“Diabetes and obesity both shorten healthspan and lifespan,” explains Sengstack. “By treating them effectively, we’re also improving the aging trajectory. And because these are well-defined conditions, we can move faster through regulatory pathways”index (9).
It’s a smart move in a space where proving actual life extension remains a long and complex process. Junevity’s work could have an impact in just a few years—not decades.
Looking Ahead: Beyond Metabolism
Though diabetes and obesity are the initial focus, Junevity’s RNA platform is highly adaptable. Other aging-related conditions like osteoarthritis, cardiovascular disease, or even neurodegeneration could be next in line.
The company is also exploring how siRNAs could modulate mitochondrial function, inflammation, and immune aging, offering a tantalizing glimpse at a future where we don’t just treat disease—we preempt it by restoring youthful gene expression.
Final Thoughts: Precision Aging Medicine Is Here
Junevity stands at the intersection of molecular precision and real-world relevance. By using siRNA to reset the transcriptional programs gone awry in aging and metabolic disease, they are crafting a therapeutic path that is both innovative and grounded in practical outcomes.
In a field crowded with buzzwords and hype, Junevity offers something refreshingly robust: science with clear logic, validated targets, and the promise of safe, durable, and deeply impactful therapies.
As the longevity field matures, we’ll need exactly this kind of focused, systems-level thinking—solutions that honor biological complexity while still aiming for simplicity in delivery and benefit.
With RNA silencing, it turns out we may not need to change who we are—just how we’re expressed.