Random film of the day — "The Hunger" by Tony Scott (1983). The vampire Miriam Blaylock, played by Catherine Deneuve, has spent two thousand years sustaining her lovers with "young blood": as long as the source is fresh, her partner doesn't age at all. But the battery has a limit. Her current companion John — David Bowie — suddenly begins aging years in a single day, and the film opens with his visit to a gerontologist, begging for help before he literally falls apart before her eyes.
Gothic? Absolutely. But behind this metaphor hides one of the strangest research programs of our time. In real laboratories, old mice were surgically fused with young ones to test whether youth transfers through blood. A startup in California sold student plasma for eight thousand dollars per liter until the FDA shut it down. And a rat named Sima lived to a record 47 months for her species on drugs derived from porcine plasma. The 1983 film and 2020s science tell essentially the same story — except the laboratory version turned out both funnier and sadder than the screen version.
"The Hunger" was Tony Scott's directorial debut — an erotic horror with Deneuve, Bowie, and Susan Sarandon, based on Whitley Strieber's novel. Audiences rejected the film: $6 million in the US and Canada, $12.3 million worldwide despite its status. Roger Ebert delivered the verdict "agonizingly bad vampire movie." Bowie himself later offered a measured assessment: the first twenty minutes move like hell — a great opening, then everything goes downhill.
The film's fate is a textbook example of inversion: within a decade, the horror became cult in goth subculture, the prologue with Bauhaus performing "Bela Lugosi's Dead" became quotable, and Propaganda magazine grew directly from its aesthetic. Today the film has 62% on Rotten Tomatoes and Saturn Awards nominations for costumes and makeup.
But the key scene isn't the vampire hunt — it's Bowie's aging. It poses the question with surgical precision: if youth is dispensed from outside, as a resource, it can also be taken away, as a resource. And this is no longer gothic, but the setup for an experiment. From this exact question, only with rats and a scalpel, more than a hundred years after the first attempt, the real science of young blood would begin.
The term "parabiosis" wouldn't appear until 1908 — para (beside) plus bios (life) — but the experiment itself predates the term by half a century. In 1864, French physiologist Paul Bert published "Expériences et Considérations sur la Greffe Animale": he surgically fused two rats into a single bloodstream and showed that fluid actually flows vein to vein through vascular anastomoses. For this work the French Academy of Sciences awarded him the prize in experimental physiology — in 1866. Bert died in 1868, not living to see his technique become a weapon of gerontology.
Heterochronic parabiosis — fusing an old animal with a young one — was first tried in the mid-1950s: Pope and colleagues (1956), then the classic work by McCay (1957) "Parabiosis between old and young rats." The results were encouraging: the old partner showed improved bone and cartilage condition, and Ludwig and Elashoff in 1972 demonstrated systematic life extension in the old partner on a large sample — especially pronounced in female pairs.
And here the technique hit the biology of inconvenience. "Parabiotic disease" — parabiotic intoxication, described as early as 1951 by Finerty and Panos — killed up to half the pairs in the first two to three weeks after surgery. Half a century later, science still couldn't solve the problem engineering-wise: fusion was too dangerous to build a career on. The subject went on the shelf for decades — until better tools appeared.
The revival was orchestrated by Irina and Michael Conboy with Thomas Rando and Irving Weissman. In February 2005, Nature published their work: heterochronic parabiosis of mice, six weeks in shared circulation — and the stem (satellite) cells in old mice's muscles awaken. The molecular switches of youth, primarily Notch signaling with delta-ligand, turn back on; regeneration of muscles and liver in old partners substantially recovers. The authors' conclusion was cautious but revolutionary in meaning: tissue aging is partially reversible, and the systemic environment matters more than the cell's own age.
In 2011, Saul Villeda and Tony Wyss-Corey at Stanford took the line to the brain. Old mice paired with young ones got a threefold increase in new neurons in the hippocampal dentate gyrus; young mice paired with old ones — conversely, neurogenesis dropped. Key detail: plasma from old mice without cells, injected into young mice, produced the same harm — worse memory, worse neurogenesis. Meaning the carrier is plasma proteins. Screening 66 immune proteins, the team found six elevated in old blood; eotaxin (CCL11) led, which rises with age in humans too. Wyss-Corey accompanied the press release with a reminder "to healthy vampires: limit yourselves to victims under thirty" — the only joke in this story that over time stopped being a joke.
Next, the industry did exactly what it does with promising proteins: appointed one culprit of the celebration. In 2013, Cell published the work of Loffredo and Wagers: circulating GDF11, growth differentiation factor 11, reduces age-related cardiac hypertrophy in old mice. In 2014, Science added vascular rejuvenation and brain neurogenesis. The dream formula appeared: one protein — and heart, vessels, and brain. Pharma smelled a contract.
Replication testing collapsed the construct. In 2015, Novartis (Egerman and colleagues, Cell Metabolism) didn't reproduce the effect and showed a counterfact: GDF11 in old blood doesn't drop but rises. In 2016, GlaxoSmithKline with Five Prime Therapeutics reported with the formula "we have been unable to confirm the reported activity of GDF11" — and in young mice, GDF11 vectors caused anorexia and weight loss. The root of the dispute turned out to be laboratory-boring: the ELISA antibodies in the first studies caught the related myostatin along with GDF11, and the "silver bullet" was largely a measurement method artifact. Mass spectrometry painted a different picture. The Scientist summed it up with a headline about conflicting conclusions — but the echo of the 2013 article was already working on investors.
While academics argued about antibodies, business went straight. In 2016, Ambrosia Medical appeared in San Francisco — founder Jesse Karmazin, Stanford Medical School graduate, unlicensed physician. Product: plasma from donors aged 16–25. Prices: $8,000 per liter, $12,000 for two. Payment — via PayPal, locations — five US cities.
The company's own clinical trial (NCT02803554, "Young Donor Plasma Transfusion and Age-Related Biomarkers") closed in January 2018: 81 participants, about 150 infusions — and participants paid the same $8,000 to participate. Results were never publicly published. A New Scientist reporter in September 2017 went through the protocol in Monterey personally: two days, a liter and a half of plasma from a young donor, private IV center of Dr. David Wright, a queue of about a hundred clients with the same checks.
On February 19, 2019, FDA Commissioner Scott Gottlieb and CBER Director Peter Marks issued a joint statement: "serious public health risks," "no proven clinical benefit of plasma transfusion from young donors for treatment, mitigation, or prevention" of aging, dementia, heart failure, plus the standard bouquet of risks — from infectious to cardiovascular. "Plasma is not approved by FDA for treatment of such conditions as normal aging or memory loss." That same day, a message appeared on Ambrosia's website about cessation of procedures "in accordance with the FDA statement." Miriam Blaylock kept her lovers on plasma for two millennia — the startup lasted three years.
The most clever answer to the whole story came from Conboy herself — in 2020, with Dobri Kiprov and the Apheresis Care Group team. They replaced half the plasma in old mice with a mixture of saline with 5% albumin — a neutral fluid, neither young nor old — without a drop of young blood. Rejuvenation of muscles, liver, and brain neurogenesis came out at the same level or stronger than with addition of young plasma. Proteomics showed the mechanics: the procedure works as a "molecular reset button," reducing pro-inflammatory proteins and allowing beneficial ones to unfold.
Retrospectively, everything converged: back in 2016, whole blood exchange of an old mouse with a young one — without fusion — didn't rejuvenate. Meaning the 2005 effect worked not through "youth factors" in young blood, but through dilution of old signals. Kiprov, whose therapeutic plasma exchange is an FDA-approved procedure for autoimmune diseases, summarized with the weariness of someone re-explaining the obvious: it will take time for people to abandon the idea that rejuvenating molecules or silver bullets sit in young plasma. Conboy formulated more harshly: it's very unlikely that aging can be reversed by changing a few proteins.
In parallel, blood stopped being an elixir and became a dashboard. In December 2023, Nature published work from the Wyss-Coray lab: 4,979 plasma proteins, 5,676 people in five independent cohorts — and LASSO models of "organ age" for 11 organs. Main conclusion: a person's organs age at different rates. Kidneys of hypertensives are roughly a year older than peers'; heart lag predicts heart failure; brain lag — Alzheimer's. From a blood test you can read which organ in a specific person is failing, without opening anyone surgically or metaphorically.
Against this backdrop, Harold Katcher and his Yuvan Research's attempt looks like the last romantic of the genre. E5 therapy — purified fraction of young pig plasma, the source honestly named: slaughterhouses. In a cohort of 16 rats, the placebo group lived 34–38 months, the E5 group — longer; record-holder Sima ("limit" in Hindi), a Sprague-Dawley female, received five infusions, outlived all her sisters by about seven months and stopped at 47 months — the oldest laboratory rat in the literature. Epigenetic clocks in the protocol article (Aging, 2023) showed a decrease in biological age of organs, Horvath called the results stunning — with a sample that can only be called tiny. Skeptic João Pedro de Magalhães politely noted that "promising" doesn't yet mean "proven rejuvenation of aging," not just individual markers. Katcher spoke of the goal to extend "youthspan," not just lifespan — and in this formula, honest and alarming at once, is the entire genre.
Social demand for "young blood" is a cyclical constant. 1970s gothic, a friendly New York Times report on the new "blood culture" in 1992, the comedic "Renfield" that same year, Silicon Valley 2017, plasma exchange clinics of the 2020s. The myth arrives ahead of science each time, and science each time must catch up — in BMJ Medical Humanities this is formulated seriously: representations of blood directly shape perception of therapy, whether medicine wants it or not.
The irony is that Miriam Blaylock isn't an allegory of science. She's an allegory of the subscription business model: eternal access to youth for a subscription fee, and the "battery" holds as long as the donor is solvent. Ambrosia reproduced her model literally, down to the price per liter — and just as surely left clients with nothing, only without the fanged reckonings.
And science, after twenty years of experiments, answers with a compromise that's prettier than the myth, though it sells worse: youth isn't a substance that can be transfused, but a balance of signals that can be disrupted in both directions. Old blood can be diluted to neutrality and get an effect; young blood — transfused and get nothing. And the same bloodstream they promised as an elixir turned out to be the best available instrument: a dashboard showing which organ is failing first. The film that flopped at the box office in 1983 guessed the form of the question. The answer turned out more prosaic than immortality — and therefore more useful.