Medical Interventions (TRT, HGH, Stem Cells, etc.) For Longevity | Lifespan w Dr. David Sinclair #5
In a Nutshell
David Sinclair examines medical interventions like TRT, HGH, peptides (e.g., MOTS-C, BPC-157), exosomes, and stem cells for longevity, cautioning they require doctor supervision, carry risks like cancer and insulin resistance, and offer short-term vitality boosts but not proven reversal of biological aging—distinguishing adversity mimetics (health-promoting) from abundance mimetics (potentially accelerating aging). Promising research includes exosomes rejuvenating senescent cells, Yamanaka-based OSK reprogramming restoring vision in aged/glaucoma mice by resetting epigenetic clocks, and Greg Fahy's triple therapy (HGH + DHEA + Metformin) reversing blood biomarkers by 2.5 years. Prioritize proven lifestyle basics (diet, exercise, sleep) to slow aging while awaiting validated clinical trials; rapid advances suggest future therapies could achieve 1:1 lifespan extension.
These notes were generated by AI and may contain inaccuracies.
Welcome to the Lifespan podcast discussing the science of aging and how to be healthier at any stage of life. David Sinclair is a professor of genetics at Harvard Medical School and co-director of the Paul F. Glenn Center for Biology of Aging Research. The series covers why we age and why we may not have to, including things to do today to increase wellness and potentially live a much longer healthier life.
Previous episodes covered biology of aging and home interventions under doctor supervision. This episode discusses interventions definitely requiring doctor's supervision, and some doctors cannot yet do but may in the future. Joined by co-host and co-author Matthew LaPlante.
Deep dive into controversial topics like stem cell therapy, peptides, exosomes, testosterone, growth hormone, and epigenetic reprogramming.
Much of the content is not FDA approved, some were available until recently but banned by FDA, now available only offshore. Significant misinformation exists. Neither speaker is a physician; David Sinclair has a PhD in genetics. Always consult a physician; podcast is no substitute.
As scientists, they read literature to distinguish fact from fiction and provide starting points for wellness.
All-in-one daily drink with 75 vitamins, minerals, whole foods, adaptogens, probiotics, digestive enzymes, vitamin C, zinc citrate. David Sinclair drinks it every morning, especially when traveling. Special offer: five free travel packs, year supply of vitamin D3 and vitamin K2 at athleticgreens.com/sinclair.
Personalized nutrition platform analyzing blood and DNA data. Presents clear data, actionable nutritional advice improving blood biomarkers. Inner age test shows biological age. Easy tests with home or clinic blood draw. 25% off at insidetracker.com/sinclair with code Sinclair.
App syncing with continuous glucose monitor. Monitors glucose impact from foods. David Sinclair joined as advisor; found grapes spike glucose, potatoes less so, avoiding highs and crashes. Skip waitlist at levels.link/sinclair.
Testosterone decreases after age 30-40 at ~1% per year in men and women. TRT market grew from hundreds of millions 10 years ago to multi-billion dollars. Used for sexual dysfunction, mental health, muscle building, fitness, vitality. People report feeling younger, more vigorous, increased libido.
Important distinction: feeling younger does not mean reversing biological aging.
Adversity mimetics (e.g., lack of food, exercise) signal body times are tough, promoting survival and long-term health. Abundance mimetics like testosterone signal times are good, build muscle, reproduce—beneficial short-term for ancestors but not long-term longevity.
Studies by Shelly Basin at Harvard: short-term improvements in libido, dose-dependent skeletal muscle mass increase, power, stair climbing, 6-minute walk distance, aerobic capacity.
Risks: worsened sleep apnea, gynecomastia (larger breasts via testosterone to estrogen conversion), benign prostatic hyperplasia (bigger prostate, nocturia), shrinking testicles, increased red blood cell production risking clots. May aggravate existing prostate cancer. Eunuchs historically live longer, suggesting testosterone supplementation may not promote longevity.
Feeling good today or medical benefits now do not address biological aging causes.
Popular for decreased exercise capacity, bone density, muscle mass, increased body fat. Short-term: feel better, grow muscle, lose fat.
Animal studies (Cynthia Kenyon): worms with low growth hormone/insulin-like signaling live twice as long. Reproduced in mice. Laron dwarfs (low IGF-1) resistant to cancer, heart disease, may live longer. Long-term HGH supplementation may increase cancer, heart disease risk.
Immediate side effects: sore joints, carpal tunnel. High levels cause insulin resistance, high blood sugar/cholesterol, edema, joint pain—increase type 2 diabetes risk. Mimics aging symptoms; signals abundance, may accelerate aging.
Benefits to restoring to normal levels, but supraphysiological doses risky.
Testosterone: Workout big muscles (thighs, back) raises natural levels.
HGH: Eat not too close to bedtime, good sleep. Try naturally first; consult doctor if needed, aim for natural healthy levels, not hyper-increase.
No anti-aging benefit from these; short-term gains possible, but not long-term.
Peptides are strings of amino acids (~100), smaller than hormones. Synthesized on machines or extracted from tissues. Cells use them for communication (e.g., brain to liver/muscle). Body makes ~1000; ~20 well-understood. Aging involves loss of cellular communication.
Distinguish adversity mimetics (recovery from damage, wound healing, lower blood sugar, increased mitochondrial activity) vs. abundance mimetics.
Insulin (best-studied peptide): Discovered 1921 by Banting and Best; extracted from dog pancreas, cured diabetic dog in hours. Human trials within months; Nobel Prize soon after. Saved type 1 diabetics from starvation diets and death within a year.
Peptide synthesis advanced in 1960s; recombinant DNA in 1978. Small peptides cheap to synthesize on machines (some make at home—off-label, not recommended).
Thousands of human studies; safe because endogenous, small, quick metabolism, low immune reaction risk.
MOTS-C (mitochondrial open reading frame of the 12S rRNA-c): From mitochondrial DNA (not nuclear; ~100 mitochondrial genes known, up from 13). Injected in mice: lowers blood sugar, increases mitochondrial activity, longevity signatures, some lifespan evidence. Human trial: reduces body fat, improves fatty liver.
Humanin: Another mitochondrial peptide.
Likely valuable for aging causes, but less known than testosterone/HGH; not proven safe/lifespan-extending.
FDA banned many in March 2020 after popularity (e.g., LA megatrend) for memory, muscle, inflammation. Stopped compounding in US; now offshore or home-made.
Risks: injection site redness, possible arthritis-like immune reactions.
- BPC-157: Increases blood flow, lowers inflammation, regenerates neurons for cognition; also weight loss.
- SS-31: Targets mitochondria, improves function; good for heart, longevity.
- GHK-Copper: In human plasma/saliva/urine; wound healing, attracts immune cells, antioxidant, stimulates collagen, protects against inflammation, reduces wrinkles, grows hair.
Evidence mostly mouse studies, clinician anecdotes; not fully validated.
Movement to make peptides available again (e.g., Thymosin Alpha-1, known since 1970s for bacteria/viral infections, potentially COVID-19).
Fat loss: Tesamorelin, CJC-1295 with Ipamorelin, AOD-9604, BPC-157.
Humanin: Mice—helps type 2 diabetes, high blood sugar, cardiovascular, Alzheimer's.
Pinealon: Treats memory/attention deficits, brain injury, stroke, chronic fatigue.
Fatigue/immune: Dixhexa, Cerebrolysin, Semax, Selank, BPC-157 with Semax/Cerebrolysin.
Experimental; effective in mice, long way to go in humans.
Placebo-controlled, double-blind clinical studies are needed before knowing if interventions are truly effective in humans, and these are underway but moving slower than desired. Making a drug takes a long time, and while people want to rush due to aging, caution is necessary due to potential negative side effects, particularly immune reactions from peptides that could be deleterious long-term.
Peptides mimicking adversity, like MOTS-C, show promise for therapies helping with aging, not just individual conditions. Research on peptides and exosomes is exploding; both are cellular signalers but differ. Exosomes are membrane-bound vesicles the size of a virus that travel easily between cells, containing multiple messages: peptides, DNA, RNA, microRNAs. They coordinate the body, e.g., signaling injury from hand to brain or vice versa, like US post mail deliveries.
Exosomes can be intercepted to diagnose diseases like cancer or infused to simulate adversity for longevity. Collecting exosomes from blood allows diagnosing injuries or diseases non-invasively. Companies like Zar Therapeutics read exosome cargo to identify origins, e.g., stage three pancreatic cancer signature from pancreas, potentially diagnosing cancer years in advance via blood test or finger prick.
Supplementing exosomes into mice bloodstreams helps with injury. August 2017 paper by Dong Shanghai at Albert Einstein College of Medicine showed hypothalamic neuronal stem cells secrete exosomes signaling the body to survive; isolating and giving them to mice extended lifespan. Deleting these cells caused aging diseases and shorter life.
Contents of exosomes are complex, making it hard to identify responsible cargoes, but identifying them could lead to targeted drugs.
2019 paper from Chinese researchers used exosome replacement for ulcer healing, concluding exosomes rejuvenate senescent cells. Senescent cells lose DNA reading ability, stop dividing, secrete inflammatory molecules, can cause cancer. Deleting them improves health in mice and likely humans. Exosomes reversing senescence would be remarkable, allowing rejuvenation instead of killing cells, e.g., in the brain.
This parallels Yamanaka factors for reversing dedifferentiation but is a new avenue.
Exosomes delivered by IV or intramuscularly, but long-term benefits/side effects unknown; caution advised. Available in some US parts, FDA watching for safety; not banned yet but may change. Not recommending immediate use; focus on education for proven future therapies.
Exosomes are highly validated; biotech/pharma investing billions in factories for disease treatment. Questions remain on long-term health, longevity, decades-long safety.
Stem cells divide asymmetrically to produce tissue-making cells, retain youth, avoid becoming one cell type. Can self-renew or differentiate into any cell type.
- Multipotent: few tissue types, from embryos.
- Pluripotent: any cell/tissue type.
Pluripotent like tree root doing anything; multipotent further down, limited options. To build mini-brain or kidney from skin cell, rewind to pluripotency via induced pluripotent stem cells (iPSCs) using Yamanaka factors.
Shinya Yamanaka (Japan, early 2010s) found genes to reprogram adult cells to pluripotency: KLF4, SOX2, c-MYC, LIN28 (OSK used in lab). Take skin/cheek cell, reprogram in ~1 week to colony of ~100 cells, grow any tissue, even sperm/egg for cloning.
In lab, mouse/human cells induced to pluripotency, trained to grow brain cells forming cerebral organoids resembling brains, from old individuals or Alzheimer's patients. Drive aging forward/reverse in organoids to study human brain quickly without patients.
- Electricity to uptake DNA.
- Liposomes (fat bubbles).
- Lab method: adeno-associated viruses (AAVs) package Yamanaka genes, infect cells; turn genes on/off with drugs.
Rewinding cell age to zero risks cancer (teratomas: hairy balls with teeth). Avoid injecting raw iPSCs.
Current therapies use autologous stem cells from fat (back/hips), purified, frozen, reinjected or into bloodstream.
Stem cells age via epigenetic changes, less regenerative (e.g., gray hair from hair follicle stem cell loss). Stem cells can be expelled from niche. Need to slow/reverse stem cell aging or replace them.
Capture young stem cells via cord blood or for adults in 20s/30s, bank for later (leukemia, modify for tissues, replace old blood). Now clear value, especially for childhood cancer; both speakers would bank for new children. Hospitals/doctors/companies handle; prepare days/week ahead. Placenta: cord blood, Wharton's jelly (hyaluronic acid, stem-rich).
Adult hematopoietic stem cells (HSCs) age, become dysfunctional, out-compete via mutations (Tet-1, Tet-2, DMTs); centenarians have few immune cell types, vulnerable to infections like pneumonia. Bank young HSCs to replace immune system later.
Used for spinal cord injuries, type 1 diabetes, Parkinson's, ALS, Alzheimer's, heart disease, stroke, burns, cancer, arthritis. Lists like this point to treating aging itself.
Potential: make organs from iPSCs/autologous cells, replace old stem cells. Drawback: don't find niche (e.g., eye injections failed, caused blindness in Florida patients, leading FDA bans). Future: rejuvenate existing stem cells in situ via reprogramming.
2017 University of Miami phase 1/2 studies: younger donor mesenchymal stem cells to frail elderly improved walking distance, lowered cytokines, better mental state/quality of life.
Mesenchymal stem cells injected in worn joints therapeutic short-term (unclear if cells stay or secrete exosomes/peptides).
Not for casual clinic visits now due to targeting issues, but future anti-aging regimen part. Keep healthy via diet/exercise/meds/supplements; then rebuild/replace cells/organs for decades more life.
Lab shifted from slowing aging to reversing via reset switch, building on Yamanaka. Full factors cause cancer/mouse death. Student Wan Chang Lu found partial set (OSK: OCT4, SOX2, KLF4, omitting oncogenic c-MYC, LIN28) reverses cell/tissue age ~80% without side effects.
Worked in cells/whole animals, focused on eye: regenerated crushed optic nerve, restored vision in glaucoma mice (pressure-induced), blind old mice.
Wan Chang sent me a text of a picture of an eye where he also regenerated the optic nerve that was crushed, and then he went on to restore vision in mice that were given glaucoma, which is pressure in the eye, and even restored eyesight to blind old mice.
Conditions targeted were damaged optic nerve cells. Used AAVs (delivery viruses) to send three Yamanaka factors into the cell. Human genome has Yamanaka genes, normally on only in embryos. Reintroduced three genes with a system turned on at will using antibiotic doxycycline. Injected virus into mouse eye—a simple 10-minute procedure, painless, similar to existing treatments for blind patients. Damaged eyes reprogrammed for a month could regrow. Mice effectively blind regained vision like young mice eyes.
Applied pressure to mimic glaucoma (major blindness cause) or aged mice to one year (essentially blind). Tested with moving lines/images; young mice show opto-motor response (head movement, like watching tennis). Measured electrical activity of nerves, age of nerve cells, genes switched on/off. Nerves reset to ~80% young gene expression patterns. Vision restored almost as good as youth.
Not just nerve cells—rejuvenated skin cells, working on muscle cells, other eye parts. Eye shape and structure rebuild like young. Optimistic for universal age-resetting mechanism applicable to mouse tissues and humans. In process, hopefully in 1-1.5 years, to restore vision in humans with glaucoma or genetic diseases.
Accesses backup copy of original epigenetic state (not genome). Genetic code unchanged; epigenetic code (DNA reader) resets. Fixes awry DNA folds from aging, exdifferentiation (cells lose identity). Analogy: polishing scratches on CD (from episode 1). Unknown how DNA loops/bundles revert. Backup of epigenome (DNA-reading structures). Eventually may develop pill instead of gene therapy to reset whole body age.
Possible via cellular reprogramming, exosomes, pills. Metformin and other drugs/supplements from earlier episode may contribute. Treatment regimen tested: starts with Metformin plus others.
Colleague Dr. Greg Fahy's triple treatment: growth hormone (HGH, raises blood sugar), DHEA (depleted in aging), Metformin. Mitigates HGH negatives. Gave for 12 months to 10 healthy men aged 51-65. Biological clock went back 2.5 years. If reverse 1 year per year, no aging.
HGH reconstitutes thymus (chest gland for T cells, immune system; degenerates with age, e.g., at age 50). But causes insulin insensitivity/glucose intolerance. Combined with diabetes therapies: Metformin, and DHEA (Fahy self-tested blood glucose control). Best effect from combo. Blood clock measure doesn't mean whole-body rejuvenation—needs other tissues, clocks.
Proteomics clock (earlier episode). Glycan age (sugars on proteins). Immuno age (immune changes). Better picture if treatment reverses aging broadly.
Clocks good short-term indicators, but unknowns in 5-10-20 years. Fahy's ongoing research: repeated treatments >1 year reduce blood clock age more, up to a decade. Jury out if true reversal or blood aspects only.
Common: early indications spur people to seek treatments overseas, internet suppliers. Understandable—aging may not be inevitable long-term. But work needed.
Since Lifespan book (2018-19), huge advances in reprogramming, measuring. Public tests for biological age from blood/spit. Hard to predict 5-10 years ahead.
Slow biological clock with steps from first episodes—buys time for therapies to mature safely. Stay young, stay alive. Pace of medicine: extra year lived = 3 extra months now; could reach 1:1 (year lived = year gained).
Aging on outside: skin, hair, nails—not superficial. Looking younger outside correlates with younger inside.
Keep David Sinclair in your library
Save the videos and channels worth coming back to, and find them again in one place.
