Listen to today's longevity lab podcastA Cornell study just found that vitamin B12 deficiency impairs skeletal muscle mitochondrial energy production — and supplementing it in aged mice actually reversed that damage.
The Biggest Rapamycin Trial in History Just Launched — 720 People, 6 Years, One Question: Can We Chemically Stop Frailty?
The University of Arizona is preparing to launch a randomized, double-blind Phase 3 clinical trial enrolling 720 participants to test whether rapamycin — an immunosuppressant drug with decades of lifespan-extension data in animals — can slow human aging, with final FDA approval expected before the trial begins this year. The trial is funded by $12 million in philanthropic support from alumnus Ken Coit and is projected to take six years. Participants will take rapamycin or a placebo for two years, with an additional year of follow-up. The trial focuses on two primary endpoints: whether rapamycin can prevent older adults from transitioning from pre-frail to frail, and whether it can reduce blood levels of IL-6, an inflammatory marker associated with frailty and age-related disease.
The frailty endpoint is a deliberate strategic choice. Rather than chasing individual diseases, the trial bets that frailty captures the underlying structural collapse that makes those diseases more likely. Community commentary from the longevity research space flagged a real tension: an earlier exploratory trial of once-weekly 6 mg sirolimus not only failed to enhance functional improvements from a home exercise program in older adults, but in sensitivity analyses may have modestly reduced those improvements — and increased the burden of minor adverse events, with a possible contribution to one serious infection.
The Arizona trial is using 8 mg per week. Observers are watching closely to see how that dose threads the needle between efficacy and immunosuppression risk. If the data comes back clean, this is the trial that hands regulators a case for the first drug explicitly approved to target aging itself.
Gobble's Take: Rapamycin has been the darling of longevity science for years — this trial will either crown it or quietly retire it, and either answer is worth six years of waiting.
Sources: r/longevity · University of Arizona News
Cornell Research Finds Vitamin B12 Affects Skeletal Muscle Energy Production
Martha Field, associate professor in Cornell's Division of Nutritional Sciences, stated: "This is the first study that shows B12 deficiency affects skeletal muscle mitochondrial energy production." The study, published in the Journal of Nutrition, identifies previously unrecognized ways B12 supports cellular metabolism and reveals early warning signals that may detect nutritional strain before classic deficiency symptoms appear.
The research mapped B12's interactions with lipid metabolism, organelle stress pathways, and epigenetic regulation — areas previous research largely overlooked. Co-author Anna Thalacker-Mercer, from the University of Alabama at Birmingham, found that B12 supplementation in aged mice improved muscle mitochondrial function. Field also noted that B12 deficiency appeared to inhibit growth or maintenance of muscle mass, with low B12 status associated with lower muscle mass and possibly reduced muscle strength.
The current findings are based on cell models and mice and will need to be validated in human studies.
Gobble's Take: A Cornell study links B12 deficiency to impaired skeletal muscle energy production — findings that may matter most for older adults with suboptimal B12 levels.
Source: r/Health
48, 192 Pounds, Bloodwork a Mess — Then 12 Weeks of Peptides and HIIT Changed Everything
A 48-year-old biohacker posted his 3-month results on r/Biohacking this week: down from 192 to 170 pounds over exactly 12 weeks, with bloodwork he described as "phenomenal." His protocol combined Retatrutide (a GLP-class peptide, dosed from 1 mg up to 3 mg), Tesamorelin for the first two months, GHK-cu daily, SS31 and MOTS-c added in the final two weeks, a 75% reduction in alcohol, and five days a week of HIIT.
The response in the comments was immediate. One user at roughly the same starting weight and age — 5'9", approaching 48 — called it "motivation and hope." Another reported a similar arc: 203 to 160 pounds from January to April, now focused on adding back muscle. What the thread captures isn't just one person's results — it's a growing cohort of men in their late 40s running peptide stacks alongside serious lifestyle changes and documenting the outcomes with bloodwork and body composition scans.
None of this is FDA-approved as a longevity protocol. Retatrutide is still in clinical development. The compounds here carry real unknowns, and "phenomenal bloodwork" in a Reddit post is not a peer-reviewed outcome. But the pattern — aggressive lifestyle intervention layered with targeted peptides, tracked obsessively — is exactly what the biohacking edge looks like before the clinical literature catches up.
Gobble's Take: The most interesting longevity data right now isn't coming from journals — it's coming from 48-year-olds with DEXA scans and a spreadsheet.
Source: r/Biohacking
Testosterone Up 2.5x, Weight Gain from 118 to 135 lbs — One Biohacker's 4-Month Stack Results
He described himself in week one as "decrepit." Four months later, before-and-after photos showed improved skin quality and visible muscle definition, with a comment section fixated on one compound: K Low. The protocol included 6.5 mg of Enclomiphene, which he reported pushed total testosterone from 600 to 1,500 and free testosterone from 100 to over 250. He added 2.5 mg of Cialis daily for blood flow following nicotine abuse from a young age, K Low for wrinkles, acne, and pain scars, CJC + Ipamorelin as growth hormone-releasing peptides, and Epithalon.
By month two, changes were largely aesthetic. By month four, a DEXA scan showed body fat moving from 8% to 9%. He went from 118 to 135 pounds, with what he described as minimal fat gain, photographed in the morning, hydrated, on creatine.
"That difference in your skin quality is crazy," one commenter wrote, already waiting on their own K Low supply.
Gobble's Take: The poster reported measurable changes in testosterone, weight, and skin across four months on this stack; the DEXA showed a modest body fat increase alongside the weight gain.
Source: r/Biohacking
In Case You Missed It
Yesterday's top stories:
- A Half-Trillion-Dollar Signal That the Longevity Era Has Officially Begun
- Rapamycin Extends Lifespan in Every Model Organism. Humans Are the Hard Part.
- Why AI-Discovered Genes May Outperform the Best Reprogramming Factors We Know
- Sleep Resets the Biology Every Longevity Protocol Is Trying to Protect
- Lifting Weights After 60 Does Something to Your Brain That Cardio Alone Doesn't
Related reads
Other Gobbles stories on similar themes.
Rapamycin Just Matched Calorie Restriction Across 167 Lifespan Studies
Biohackers Are Ditching TB-500 After Cancer Warnings Hit Home
After 20 Years and Hundreds of Compounds, One Drug Keeps Winning: Rapamycin
Seven supplements walk into a lab — not all of them make it out
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