When people first hear about mitochondrial peptides like SS31, MOTS-c, and Humanin, they often want to know which one is “best.” The truth is that each works on different levers inside the cell, and the right choice depends on what system is most stressed. Instead of guessing, we can use both objective markers and subjective markers to guide decisions. The key is to think of mitochondria as adaptable power plants. Each peptide teaches the plant a different skill SS31 strengthens the wiring, MOTS-c teaches it to use different fuels, and Humanin helps it resist damage signals. By paying attention to how our bodies respond, we can run small experiments and see what creates real improvements. The first place to start is redox stress. This is the balance between energy production and the “sparks” of free radicals that leak out. When sparks overwhelm the clean-up systems, we get fatigue, brain fog, and recovery issues. Labs like glutathione ratios or 8-OHdG give objective clues, but we can also use simple subjective markers. If someone feels like their workouts leave them drained for days, if their energy crashes mid-afternoon, or if their mood dips after training, redox stress may be the limiting factor. In that case, SS31 is often the best starting tool. SS31 binds to cardiolipin in the inner mitochondrial membrane, stabilizes the electron transport chain, and reduces the leakage of reactive oxygen species. In plain terms, it stops the wires from sparking and helps energy flow smoothly. Subjectively, people notice less soreness, steadier energy, and a calmer nervous system. HRV often improves, and the same training feels easier. If those markers shift in the right direction, SS31 is likely doing its job. The second area to evaluate is metabolic flexibility, which is the ability to switch between carbs and fats as needed. Poor flexibility shows up as high fasting insulin, high triglycerides, or simply the feeling that you “hit the wall” quickly without carbs. On a bike or during zone two cardio, if your heart rate climbs quickly and you feel like you cannot settle into a pace, that points to a problem in fuel choice. MOTS-c is the peptide that best addresses this. It activates AMPK, which signals the cell to clean up inefficient processes and shift toward fat oxidation. In practice, this means glucose uptake improves, fatty acid breakdown becomes more efficient, and new mitochondria are built. Subjective markers here include easier endurance work, steadier blood sugar, less hunger between meals, and a more even mood. On the performance side, lactate production during submaximal efforts goes down and zone two feels more sustainable. When those changes show up, MOTS-c is proving useful.

I just listened to a recent podcast with Dr. Dom D’Agostino, whom I’ve been following for almost two decades and whose opinion I highly value. If I understood correctly, he doesn’t seem particularly enthusiastic about ketone esters. (I know this may be related to the promotion of ketone salts, but he is probably the most important ketone researcher at the moment.) His reasons: a) The rapid and excessive rise in ketones triggers an insulin response, which in the context of fasting and a ketogenic diet is not ideal. I assume it may make sense post-workout, when glycogen stores are being replenished. In addition, this insulin release suppresses endogenous ketone production. b) The second reason seems more concerning. Ketone esters are said to be metabolized by the liver in a way similar to alcohol, and if used too frequently or long-term, they could place a heavy burden on the liver—especially in older individuals or those on multiple medications. He also mentioned a new triester, without the alcohol part, as a potentially better next-generation option. Overall, he seems to favor a combination of MCTs and ketone salts, which both boost endogenous ketone production and provide some exogenous ketones. The electrolytes included are not a problem ( within a ketogenic diet—in fact, they are beneficial) .

I have a client diagnosed with osteopenia who would like to address the problem. The client is woman middle-aged. In addition to dietary changes, sufficient protein intake, weight-bearing exercise, and supplementation with Vitamin D3 + K2 + calcium, are there also any peptides that could be useful?

Monthly Q&A is Wed, Sept 24th at 12pm EST! Peptides, mitochondria, training, recovery, redox, nutrition nothing off limits. Can’t make it? It’s recorded. Send your questions ahead & I’ll tackle as many as possible. Don’t miss this one! Anthony Castore is inviting you to a scheduled Zoom meeting. Topic: Anthony Castore's Zoom Meeting Time: Sep 24, 2025 12:00 PM Eastern Time (US and Canada) Join Zoom Meeting https://us06web.zoom.us/j/3374982270?pwd=df4BMZNo1LubZaVOX40y7ApApJMNh1.1&omn=86062393294 Meeting ID: 337 498 2270 Passcode: 12345 --- One tap mobile +13052241968,,3374982270#,,,,*12345# US +13017158592,,3374982270#,,,,*12345# US (Washington DC) Join instructions https://us06web.zoom.us/meetings/86062393294/invitations?signature=ifWS2d8Nthqfmi1D1qiFFAu-MxuZwFKHQvHy7dxGD68

Does anyone have experience using TA-1 with severe seasonal or environmental allergies that often turn into sinus infections. If so, what’s been your experience ? Would it be better as a prevention or response to acute infection ? I’m familiar with histamine reducing supplements and enzymes but am specifically curious about peptide support here. TIA.