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Castore: Built to Adapt

812 members • Free

5 contributions to Castore: Built to Adapt
Demystifying Membrane Potential: What It Is, Why It Matters, and Why Structure Comes First
I recently had a great conversation with Alex Kikel that got me thinking, membrane potential is one of the most referenced yet least understood concepts in mitochondrial biology. We throw around numbers like “-150 mV” or “polarized vs. depolarized” as if that explains anything. But if you’re not rooted in the mechanisms, it’s noise. This article is meant to demystify membrane potential, what it actually is, what builds it, what breaks it, and why structure determines whether it even matters. Let’s begin at the core: membrane potential is the electrical charge across the inner mitochondrial membrane (IMM). It’s not the cause of energy production, it’s the result of a system working in sync. And that system only works if structure, morphology, and proteomic integrity are intact. The IMM is lined with proteins from the electron transport chain (ETC) (Complexes I through IV) which pass electrons downstream, pumping protons (H⁺) from the matrix into the intermembrane space. This creates a proton gradient, separating charge across the membrane. That separation is membrane potential an electrochemical voltage that becomes the force used to make ATP via Complex V (ATP synthase). But it’s not just about voltage. It’s about stoichiometry. Think of membrane potential as pressure in a hose. If the hose is kinked, or the nozzle is leaky, pressure becomes meaningless. In mitochondria, that pressure only becomes useful if: 1. Electrons flow properly (via NADH/FADH₂ donation), 2. Protons are pumped efficiently (via structurally competent complexes), and 3. The ATP synthase turbine is functional and matched to demand. Structure comes first. If cristae (the folds of the IMM) are damaged, the spatial orientation of ETC complexes falls apart. The distance between proton pumps and ATP synthase increases, electron slippage occurs, and ROS increases. You can’t maintain meaningful membrane potential when architecture collapses. This is where morphology and fusion-fission dynamics enter.
0 likes • 3d
@John O'Mahony What worked for me, with regard to monitoring the effects of SLU, was a wearable health monitoring device. In my case the Helio Strap which is a pretty good Whoop knock-off. It does good sleep tracking and it also keeps tabs on your SpO2 and heart rate during the day. It has a feature it labels PAI (personal activity index maybe?) that will give you a daily score based on your activity. The score mostly seems to be increased by getting into and staying in aerobic heart rate ranges for periods of time. The "wow" realization for me with SLU happened by accident one day about a month ago while checking this metric (which I don't always even do). That day I had decided to take my biggest ever dose of SLU since I was nearing the end of my bottle (a liquid suspension). Up to that point I had taken anywhere from 500mcg to 2-3mg daily and up to 20mg a couple of times. I was on the fence about whether it was having beneficial effects for me. Sometimes I'd sweat a little more readily working out. With one of the larger doses I had felt a 'vibration' sensation throughout my body when laying down for bed that night. Well, this particular dose would have been somewhere in the 100mg range. I took it fasted, first thing in the morning with most of my other supplements. The day went by as normal. I didn't feel any different--I had kind of forgotten about the big dose. That night I went and played two hours of 4-man sand volleyball. This was a weekly thing for me on that day of the week. There was nothing especially different about this day. My sleep had been about the same as the week prior. My nutrition roughly equivalent. My workday hadn't been vastly different. The week before my PAI score had been in the mid twenties, which was really good, one of my higher single activity PAI scores I had achieved. My heart rate at sat in the mid 140s for a while during play (I'm 48, for reference). 1.5 hours in the gym doing what I would call a somewhat intense workout usually gets me about a +10 on PAI, and half of that is my time on the hack squat. Well, this night my PAI score was in the mid 60s. My heart rate had been in the low 170s for a little bit. I hadn't noticed it at all during play. I felt great. But now I know, SLU really does work.
Podcasts
Podcasts are the ultimate multitasking hack. 🎧 Think about it—you can dive deep into cutting-edge science while folding laundry, walking the dog, driving to work, or prepping your morning coffee. Knowledge is power, and podcasts make learning effortless and fun. I’m continually building out my library of episodes, and your feedback—positive, negative, or somewhere in between—is invaluable. Drop your thoughts or questions below; I genuinely look forward to hearing from you and answering any questions you have. Let’s grow smarter together. links for podcasts https://podcasts.apple.com/us/podcast/be-activated-with-anthony-castore/id1265819314?i=1000440879065 https://podcasts.apple.com/us/podcast/episode-38-exploring-peptides-and-health-with-the/id1716132914?i=1000664221672 https://podcasts.apple.com/us/podcast/the-irrelevant-podcast/id1694567876?i=1000641226578 https://podcasts.apple.com/us/podcast/the-coaches-corner-university-podcast/id1686472964?i=1000678527754 https://podcasts.apple.com/us/podcast/episode-71-10-under-the-radar-wada-approved/id1716132914?i=1000700488642 https://podcasts.apple.com/us/podcast/77-anthony-castore-qna-peptides-fat-loss-muscle-building/id1665061482?i=1000704751475 https://podcasts.apple.com/us/podcast/athlete-builder/id1715521920?i=1000695436197
1 like • 3d
Drew is a great host. Maybe a little on the sycophantic side with his guests at times, but very respectful and always lets his guests get everything they want to say out before interjecting with a good guiding follow-up question or anecdotes about what was just said. This was a very good episode.
Trekrezan and my very short experience
Dropping this post to drum up a discussion on Trekrezan. I am currently through my planned administration of this compound. I have experienced a very nice result as of so far. My goal of this product is in the realm of athletic performance and adaptation. Limited information/ practical application studies has bent my arm to trying it. My so far experience has been what I would consider impressive. I am experiencing a 12% to 18% gain on reps on my working sets of weight training in a one week time period. This is on a high volume high intensity training ( 3-5 sets per exercise of 15 to 20 reps per exercise with 1.5 rest periods between sets). With my cardio ( ergo rower 2000 meter test for time) seeing a mirroring result in percentage of time reduction as in my expansion in reps of weight training. My recover from the pre planned workouts has been significantly improved and is at a level of my late 20’s and I am 48 years old. I am extremely excited to see if the increases/ decreases will continue and or how long they will last after the cycles of the compound is completed. I have dosed this at 3 tabs a day on day one, 2 tabs a day on days 2-4, and one tab 1 tab a day on days 5-7.
0 likes • 3d
After you've had a long time to reflect on your experience with Trekrezan, what are your thoughts on it?
Anthony’s Thoughts
@Anthony Castore would love your thoughts on this video. I received it from a bunch of people. I don’t agree with his overall logic based on personal experience and that of a couple dozen others I personally know. The comments show even more. Studies never (or rarely) show micro dosing. And I also realize micro dosing has been bastardized from its original meaning to be more of a split dosing protocol. Studies typically deal with those that have T2D and/or Obesity and we know metabolically that’s not the same at all as someone just wanting a boost or reset that maybe has low-grade insulin resistance or inflammation, etc. https://youtu.be/PZtKV9DjRxQ?si=9AQiebL7MStjHOTX
2 likes • Nov '25
@Brady Nielson I'm with your wife on this one. I generally gobble up as much content about this stuff as I can but I tried to watch a couple of his videos and couldn't make it very far. I can't take his try-hard tough guy schtick seriously. @Anthony Castore Dean St. Mart on the most recent metabolic round table with Steve and Kurt was red team/blue teaming this subject and agreed with what you said from an "on paper" perspective but went on to say that micro dosing might have better real world results for some because underground GLP-1 meds, whilst generally having close to the advertised dosing of included GLP-1 formulation, could differ significantly in the rest of the formulation such as carrier chemicals and what-not and that could actually effect the half-life vs. the pharmaceutical version.
ATX 304
@Anthony Castore you mentioned this in the last Q&A and I was curious if this is coming here on this platform or elsewhere because I’m very curious 🧐 to hear your input.
0 likes • Nov '25
@John Cook It's hard to conclusively say how a mouse dose should convert to human dosing. In a deep dive about clenbuterol I listened to recently they said that using the mouse to human dosing conversion in the animal studies they conducted with clen it would have come out to 10mg daily for humans. We know enough about the effect clen has on humans to assume most peoples hearts might explode at that dose.
1 like • Nov '25
@Joe P Gemini seems pretty confident that it has a half-life in humans of 10-12 hours so dosing multiple times per day seems unnecessary to me.
1-5 of 5
Chris Lack
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@chris-lack-3255
An old guy who's into peptides and small molecules

Active 3h ago
Joined Nov 12, 2025
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