Habits and Hustle

Episode 493: Ben Greenfield: How to Actually Look 20 Years Younger + His Most Extreme Biohacks Revealed

October 14, 2025

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  • Digestive enzymes, especially for those over 40, are crucial for breaking down protein and unlocking nutrients, with plant-based proteins seeing a significant bioavailability boost when enzymes are included. 
  • For brain health and information retention, focus on providing building blocks like oleic acid (from olive oil) and DHA (from fish oil) for myelin sheaths, and amino acids/Vitamin B for neurotransmitters, rather than just stimulants. 
  • Concurrent training (combining strength and cardio) is the superior exercise method for fat loss compared to focusing solely on strength or low-intensity aerobic training like the 12-3-30 treadmill trend, due to higher total calorie burn and post-exercise oxygen consumption (EPOC). 
  • Ben Greenfield attributes the cessation of his "food noise" to GLP-1 microdosing, which removed the anxiety associated with constant thoughts about eating. 
  • Ben Greenfield detailed several extreme biohacks he has undergone, including replacing his blood with young plasma for $40,000 and undergoing full-body stem cell procedures. 
  • Ben Greenfield believes that permanent relief from shame, guilt, and fear comes from faith and forgiveness, contrasting this with the temporary nature of psychedelic experiences used for similar purposes. 

Segments

Brain Retention and Information Storage
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(00:01:30)
  • Key Takeaway: Brain retention relies on providing building blocks for neuroplasticity, not just stimulants like caffeine.
  • Summary: Effective brain function requires providing fuel for the brain, specifically oleic acid and DHA for myelin sheaths, and amino acids supported by Vitamin B for neurotransmitters. The speaker attempts to clear his brain of non-essential information, similar to Sherlock Holmes, to maintain a cleaner head for retention. Supplementing with digestive enzymes alongside protein intake is recommended, especially after age 40, to maximize amino acid availability for neurotransmitter formation.
Digestive Enzymes and Nutrient Absorption
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(00:06:43)
  • Key Takeaway: Digestive enzymes improve nutrient unlocking, and their use is generally recommended after age 40 as pancreatic enzyme production naturally decreases.
  • Summary: Digestive enzymes contain proteases, amylases, and lipases to break down protein, carbs, and fats, respectively, leading to better nutrient absorption. Taking enzymes before a meal is optimal, but they still provide benefits if taken afterward, even if forgetting to take them beforehand. Digestive enzymes can make plant-based protein bioavailability equal to animal-based protein bioavailability.
Glucose Disposal Agents and Bitters
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(00:10:19)
  • Key Takeaway: Bitter compounds act as natural glucose disposal agents (GDAs) by stimulating GLP release and improving satiety.
  • Summary: GDAs like berberine, dihydroberberine, and bitter melon extract help manage blood sugar spikes by increasing insulin sensitivity or glucose transporter expression. Anything bitter, including bar bitters ordered at a restaurant, functions as a GDA and can mildly stimulate GLP, offering a mild satiation effect with meals. Lifting weights or cold exposure are potent, non-supplemental methods for improving acute insulin sensitivity and glucose disposal.
Cold Plunging Effects on Females
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(00:17:03)
  • Key Takeaway: Metabolically, cold exposure appears beneficial for women, showing better metabolic responses than men in some studies, despite initial higher cortisol spikes.
  • Summary: Women are generally more sensitive to cold due to lower muscle mass and hormonal fluctuations (estrogen/progesterone) causing vasoconstriction during the luteal phase. Studies suggest that regular cold exposure can chronically lower cortisol in women after an initial adaptation period, indicating a stress-resilience effect. Short cold plunges (2-3 minutes) are unlikely to impair exercise adaptation, unlike prolonged exposures (10-20 minutes) that significantly drop muscle tissue temperature.
Sauna Use Relative to Exercise
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(00:23:15)
  • Key Takeaway: Sauna use post-exercise maximizes performance benefits like EPO and heat shock protein production, whereas pre-heating can shift blood flow away from muscles needed for strength work.
  • Summary: The greatest performance-enhancing benefits from sauna use, such as increased red blood cell precursors (EPO) and heat shock proteins, occur when used after exercise. Working out in a hot environment increases cardiovascular demand and perceived exertion, which can be beneficial for pure cardio goals but detrimental to strength and power due to blood shunting to the skin for cooling. Optimal strength training is best performed in cooler environments (65-70 degrees) to maximize blood flow to working muscles.
Fat Loss Exercise Efficiency
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(00:30:02)
  • Key Takeaway: Concurrent training, combining strength and cardio, is the most superior exercise modality for fat loss compared to isolated strength or aerobic training.
  • Summary: The best exercise order for fat loss is concurrent training, followed by aerobic training, and then strength training alone, though strength training is key for body composition change. Zone two cardio burns a higher percentage of fat, but high-intensity training burns significantly more total fat calories due to higher overall caloric expenditure and elevated post-exercise oxygen consumption (EPOC). The 12-3-30 treadmill trend is less effective for body composition change than varied programs incorporating strength and HIIT.
Overtraining Warning Signs
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(00:39:02)
  • Key Takeaway: Early warning signs of overtraining and nervous system dysregulation include elevated resting heart rate and body temperature for multiple consecutive days.
  • Summary: If you cannot get blood tests, look for consistent elevated resting heart rate and body temperature, feeling ’tired but wired’ leading to poor sleep, and fluid retention (swelling) as signs of chronic stress and cortisol dysregulation. If ignored, this can lead to long-term metabolic slowdown, characterized by feeling cold and sluggish due to potential thyroid downregulation. However, most people need to focus more on foundational habits like moving more and eating fewer calories than worrying about minor food additives.
Electrical Muscle Stimulation (EMS) Effectiveness
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(00:45:48)
  • Key Takeaway: Full-body EMS suits are effective biohacks for muscle stimulation, capable of recruiting motor units the brain may have forgotten, but they cause significant soreness.
  • Summary: EMS suits bypass the central nervous system governor, forcing muscle contractions that can lead to soreness in previously underutilized muscles, making them useful before long periods of sedentary behavior. The technology is effective for muscle recruitment but inconvenient to use and can leave the user too sore to train conventionally for days afterward. The speaker suggests using EMS strategically before long flights to preemptively manage restlessness.
Useless vs. Surprising Biohacks
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(00:48:03)
  • Key Takeaway: Fat oxidation boosters like green tea extract offer negligible weight loss benefits, whereas microdosing GLP-1 agonists can serve as ’training wheels’ for appetite control.
  • Summary: Thermogenic agents that claim to amp up fat oxidation provide such a small bump that they are useless for appreciable weight loss, despite being heavily marketed. Conversely, microdosing GLP-1 agonists (like one-tenth of a standard dose) can effectively retrain the brain to ignore ‘food noise’ without the severe side effects of nausea or anhedonia associated with full therapeutic doses. This temporary suppression allows individuals to learn new satiety cues, similar to how Viagra can break a mental block for erectile function.
GLP-1 and Food Noise
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(00:58:41)
  • Key Takeaway: GLP-1 microdosing eliminated the speaker’s ‘food noise’ and the anxiety associated with constant meal planning.
  • Summary: The speaker no longer experiences ‘food noise’ due to GLP-1 microdosing, which removes the distraction of constantly thinking about or planning the next meal. This allows for greater focus during social situations like dining out. The speaker cautions that one must still be careful not to under-eat while on this regimen.
Biohacking Origins and Career
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(01:00:22)
  • Key Takeaway: Ben Greenfield’s biohacking journey began in college bodybuilding, evolving through extreme endurance sports testing.
  • Summary: The speaker’s experimentation started in college bodybuilding, using cheap supplements like creatine and experimenting with pre-workouts. This evolved into testing fueling strategies during Iron Man triathlons and adventure races. Now, his role involves trying things out to report back from an immersive journalistic standpoint.
Career Planning and Structure
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(01:01:37)
  • Key Takeaway: Valuing time over money leads to strict daily habits but maintaining openness for seizing unexpected opportunities.
  • Summary: High achievers often prioritize time, leading to strict daily routines for efficiency and deep work, avoiding time-wasting activities like doom scrolling. The speaker avoids rigid 10-year business plans, preferring to remain open to opportunities that arise. This approach prioritizes effectiveness over maximizing wealth accumulation through building to sell.
Extreme Biohacking Experiments
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(01:05:35)
  • Key Takeaway: Extreme experiments included young plasma replacement ($40K), full-body stem cell procedures, and vagus nerve nerve blocks.
  • Summary: Ben Greenfield detailed having his plasma replaced with young donor plasma as a ‘full oil change’ for his body. He has also undergone full-body stem cell injections and stellate ganglion nerve blocks to reset the vagus nerve, which significantly boosts HRV. These procedures are done to test extreme optimization methods.
Psychedelic Use and Spiritual Danger
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(01:07:40)
  • Key Takeaway: Heroic doses of psychedelics are considered spiritually dangerous because they risk crossing into dimensions where one can interact with negative entities.
  • Summary: The speaker stopped taking large amounts of psychedelics because he believes they allow crossing a spiritual portal, potentially exposing users to entities like demons or angels. He described an intensive, recorded experience near Nashville involving a precise cocktail of entheogens designed to down-regulate the default mode network. The primary benefit derived was profound transparency and honesty in his relationship with his wife.
Trauma Healing and Spiritual Release
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(01:24:42)
  • Key Takeaway: Permanent release from shame and guilt is achieved through faith and forgiveness, not solely through temporary psychedelic experiences.
  • Summary: While psychedelics can temporarily open access to past traumas for processing, the speaker argues that true, permanent relief from shame and guilt comes through faith, specifically referencing the Christian concept of forgiveness. This spiritual interaction provides an unconditional acceptance that chemical means cannot permanently replicate, filling the ’eternal hole in the soul.'
Recommended Diagnostic Testing
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(01:32:33)
  • Key Takeaway: Reliable health data comes from genetic tests, quarterly blood panels, hormone panels (saliva/urine), and gut microbiome testing.
  • Summary: Environmental toxicity tests are considered unreliable due to potential result variance, though awareness of mold and microplastics is important. Key tests include genetic screening, quarterly basic blood panels for lipids and vitamins, and annual metabolomic tests for micronutrients. Hormone fluctuations are best captured via saliva/urine, and gut health is assessed via stool analysis for bacterial balance and inflammation.
Anti-Aging Skincare Routine
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(01:35:30)
  • Key Takeaway: Effective anti-aging involves consistent collagen intake, weekly microneedling/clay masks, and thrice-weekly red light therapy.
  • Summary: For skin health, consuming 20-40 grams of collagen and essential amino acids daily provides necessary building blocks. The speaker derma-rolls weekly, followed by a clay mask, and uses a red light mask three times weekly to increase blood flow. Topical products containing bioabsorbable anti-aging peptides, like spermidine, are also incorporated into the daily regimen.
Plasma Therapy Effects
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(01:38:09)
  • Key Takeaway: The $40,000 young plasma replacement therapy resulted in feeling ‘unstoppable’ for about four weeks, with lingering benefits.
  • Summary: The plasma replacement therapy, similar to procedures done by Bryan Johnson, involved infusing young, healthy male donor plasma. The immediate effect was feeling younger, recovering faster, having higher libido, and experiencing mental clarity. While the peak effect lasted about four weeks, the speaker still felt better five months later and would consider repeating the procedure every five years.
Faith Development Through Hardship
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(01:30:59)
  • Key Takeaway: Hardships and life challenges, like financial struggles and marriage difficulties, deepen faith, refining it like gold through fire.
  • Summary: The speaker grew up in a Christian household, but experiencing life’s difficulties—paying bills, raising children—has deepened his faith. He views hardships as the fire that refines gold, contrasting this with those whose faith weakens under duress. This optimistic perspective sees bad things happening to allow the good things to shine through at a higher level.