Each week we summarize new research on longevity, peptides, and regenerative medicine in plain language. Every summary includes the studies it is based on so you can read the source yourself. This week covers three topics.
NAD+ boosters and IV drips: what is actually proven?
- NAD+ is a molecule every cell uses to make energy. Levels fall with age. Supplements called NMN and NR are meant to raise it.
- Trials show these supplements can raise NAD+ in the blood and are generally safe in the short term, but clear benefits in healthy people are still unproven.
- NAD+ IV drips are popular and expensive. There is little evidence they work better than pills, and experts say the marketing is ahead of the science.
NAD+ is a helper molecule used in hundreds of reactions, especially energy production. Because it declines with age, and because raising it helped aging mice in famous experiments, it became a longevity target.
In people, several small trials show that NMN and NR can safely and meaningfully raise NAD+ levels over a few weeks. But when researchers look for real-world benefits — more energy, better fitness, slower aging — the results are mixed and mostly preliminary. Some signals appear in specific groups, such as people with prediabetes or artery disease, but not in healthy adults broadly.
IV NAD+ drips are a separate, larger claim. They are costly, largely unregulated, and not shown to beat much cheaper oral supplements. As one Harvard physician put it, “The marketing has gotten way out ahead of the science.” For now, the honest summary is: safe to raise NAD+, unproven that doing so helps a healthy person live longer.
- "Marketers say NAD+ pills and infusions can boost longevity. What’s the evidence?" NPR, 2026. npr.org
- "The safety and antiaging effects of nicotinamide mononucleotide in human clinical trials: an update." Advances in Nutrition, 2024. sciencedirect.com
GLP-1 drugs beyond weight: the heart and kidney data
- GLP-1 drugs were first made for type 2 diabetes and are peptide-based medicines.
- Large trials show semaglutide lowers the risk of heart attack, stroke, and cardiovascular death in certain higher-risk patients.
- The FLOW kidney trial found semaglutide cut the risk of kidney failure and related outcomes by about 24 percent in people with type 2 diabetes and chronic kidney disease.
Most headlines about GLP-1 drugs are about weight. But some of the strongest evidence is about the heart and kidneys.
In large randomized trials, semaglutide reduced major cardiovascular events — heart attacks, strokes, and cardiovascular death — in higher-risk patients. The FLOW trial, focused on the kidneys, found that semaglutide lowered the combined risk of kidney failure, large drops in kidney function, and related death by roughly a quarter in people with type 2 diabetes and chronic kidney disease. Pooled 2026 analyses point the same way across heart, kidney, and death outcomes.
Researchers think part of this protection goes beyond weight loss itself. These are still prescription drugs with real side effects and costs, and the strongest evidence is in people with diabetes or established disease, not the general public.
- "Semaglutide and kidney outcomes in type 2 diabetes and chronic kidney disease (the FLOW trial)." New England Journal of Medicine, 2024. nejm.org
- "Effects of semaglutide on mortality, cardiovascular, and kidney outcomes: a systematic review and meta-analysis." Cardiovascular Diabetology, 2026. springer.com
Umbilical-cord stem cells for knee arthritis
- These are mesenchymal stem cells collected from donated umbilical cords after healthy births.
- A 2026 systematic review and meta-analysis found the injections appeared safe and may reduce pain in knee osteoarthritis.
- The evidence quality is still mixed, and preparations and doses differ from clinic to clinic.
Mesenchymal stem cells are cells that can calm inflammation and support tissue repair. Umbilical-cord tissue is a rich, young source of them, which is why it is used in joint research.
A 2026 review that pooled the available trials concluded that cord-derived stem cell injections for knee osteoarthritis were generally safe and were linked to reduced pain and some functional improvement. That is encouraging for a condition where cartilage does not heal well on its own.
The caution is the same one that runs through this field: trials are often small, methods are not standardized, and clinics prepare and dose these cells differently. Promising early evidence is not the same as a proven, regulated treatment, and marketed “stem cell” clinics vary widely in quality.
- "Regenerative therapy in osteoarthritis using umbilical cord-origin mesenchymal stem cells: a systematic review and meta-analysis." 2026. ncbi.nlm.nih.gov
- "Global clinical trial landscape of stem cell-based therapies for osteoarthritis." Frontiers in Cell and Developmental Biology, 2026. frontiersin.org