The Peptide Reference: What BPC-157, TB-500, Tesamorelin, MOTS-c and GHK-Cu Actually Do

A plain-language, evidence-graded guide to the peptides people ask me about most. For each one: what it's claimed to do, what the research actually shows, and where I have personal experience, exactly what I noticed (which is not the same as proof).

🟢 Strong: multiple human RCTs or established clinical consensus. 🟡 Moderate: at least one good human RCT, or consistent human data. 🟠 Early: small/pilot human studies, or strong animal data not yet confirmed in humans. ⚪ Anecdotal: mechanism, community reports, or n=1 only.

The honest headline: the marketing talks like the evidence is green, but for a lot of these it's actually orange. The gap between those two is the whole reason this page exists.

Growth hormone releasing hormone analog. A prescription peptide that signals your body to make more of its own growth hormone.

Claimed: burn visceral (belly) fat, improve body composition, better sleep, anti-aging.

What the evidence shows: 🟡 Moderate-to-strong, and it's the rare peptide here with real human RCT data. FDA-approved (as Egrifta) for reducing visceral fat in HIV-associated lipodystrophy, based on two Phase 3 placebo-controlled trials: roughly 15% visceral fat reduction at 26 weeks, about 18% at 52 weeks, with no change in subcutaneous fat. The catch the marketing skips: the gains reverse when you stop, and long-term and cardiovascular safety data is thin. Use outside HIV lipodystrophy is off-label, so the strong data sits in a specific population.

My experience (n=1, not proof): The one I have the most time on, and the one I'd point to first if someone asked what actually did something for me. Ran it at a low dose for about three months and held everything else flat, same training, same protein, same routine, because I wanted to know what the compound was doing, not what a new diet was doing. The first thing I noticed wasn't fat, it was sleep, deeper, the kind where you wake up rested. Energy followed, appetite came back in a way that felt normal. The visceral fat was the headline: it came off the abdomen specifically, I went from a 32 to a 28 waist, and the muscle stayed. That lines up with the trials, which is reassuring, but I'm one guy with no control group. A clean data point, not proof it'll do the same for you.

A synthetic peptide based on a sequence found in stomach acid. The community's go-to for healing.

Claimed: heal gut, tendons, joints, ligaments, reduce inflammation.

What the evidence shows: 🟠 Early, and this is the honest gut-punch. There are 100+ rodent studies showing consistent tissue-healing effects, which is genuinely interesting. But as of 2026 there are only a handful of small human pilot studies and zero randomized controlled trials. We don't even have solid data on how humans metabolize it. "Promising in rats" describes a long list of compounds that later failed in people. The animal data is real; the human proof isn't there yet.

My experience (n=1, not proof): I never ran BPC-157 on its own. I ran it as the "Wolverine stack," paired with TB-500, so right up front: I can't tell you which of the two did what. What I can tell you is what the pair did together, and the clear signal was recovery. Sessions that used to leave me wrecked for three days had me back in about two. Consistent enough that I noticed without looking for it. The gut benefits BPC-157 is famous for, I've got nothing useful to report. No obvious change, but I wasn't dealing with a gut issue at the time, so maybe there was nothing to fix. One person, no control, two compounds at once. Treat the recovery note as a data point, not a verdict.

Synthetic version of a repair protein found in nearly all cells.

Claimed: speed tissue recovery, heal injuries, reduce inflammation, often stacked with BPC-157.

What the evidence shows: 🟠 Early for the recovery claims. Most support is preclinical (cell and animal wound-healing models). Human data for the systemic-recovery use is essentially absent. One thing the hype rarely mentions: thymosin beta-4 promotes new blood vessel growth, and that mechanism has been linked in some studies to tumor-growth concerns. Worth knowing before treating it as casually safe.

My experience (n=1, not proof): Same story as BPC-157, because I only ran the two together as the Wolverine stack. The pair noticeably shortened my recovery between hard sessions, roughly three days down to two, and I genuinely can't separate how much was TB-500 versus BPC-157. If I ever run TB-500 solo I'll update this with a cleaner read.

Growth hormone secretagogues. They nudge the pituitary to release more growth hormone.

Claimed: better sleep, recovery, fat loss, lean mass, anti-aging.

What the evidence shows: 🟠 Early for the real-world outcomes. These reliably raise growth hormone and IGF-1 in humans, that part is measurable and real. What's missing is good long-term human trials showing the raised numbers translate into the body-composition and anti-aging outcomes people chase, especially in healthy adults. Mechanism solid; outcome proof thin.

My experience (n=1, not proof): I ran ipamorelin alongside tesamorelin, so this is a two-compound read. The way it split out in my head: tesamorelin did the heavy lifting on visceral fat, and the ipamorelin seemed to put a little more bulk back on the muscle while I cut. That mattered, because the thing nobody warns you about with aggressive fat loss after 40 is looking deflated. The usual move is to add CJC-1295 to push GH harder. I don't. I'm 49, I don't need to look huge; at my age visceral fat is the thing quietly bad for me, so that's what I optimize against, not the mirror. Personal call, not a recommendation.

A peptide encoded by your mitochondria. The "exercise in a vial" pitch.

Claimed: boost mitochondrial function, metabolic health, endurance, healthy aging.

What the evidence shows: 🟠 Early, with a wrinkle. Your body makes MOTS-c naturally and exercise raises it, with solid human observational data on that. The mouse data is eye-catching (it roughly doubled running capacity in older mice). But injected MOTS-c as a therapy has essentially no human clinical trials, and development has stalled partly on delivery (it breaks down fast, absorbs poorly). Real biology, genuinely promising, but the "inject it and get the mouse results" leap isn't proven in people.

My experience (n=1, not proof): The one that surprised me, and the one I'd run again without hesitating. The effect I felt was energy, real and usable, not a jittery stimulant buzz. I timed it: morning dose, gym a few hours later, and on those days I went harder. Then the Wolverine stack handled recovery from the harder sessions. I basically built a loop: MOTS-c to put more in the tank going in, the stack to recover coming out. Closest I've felt to training like a younger version of myself. Big caveat I won't bury: human data for injected MOTS-c basically doesn't exist. This is me reporting how it felt, fully aware it's exactly the kind of n=1 enthusiasm I tell everyone else to be skeptical of.

A naturally occurring copper-binding peptide that declines with age.

Claimed: skin firmness and wrinkles, hair growth, wound healing, anti-aging.

What the evidence shows: 🟡 Moderate, but specifically for topical use on skin and hair, which is where the human data is. Controlled studies show topical GHK-Cu stimulates collagen and elastin and improves skin firmness, fine lines, and density over ~12 weeks, and a 2022 RCT found it raised hair density (beating minoxidil in that study). The injected "longevity" claims are a different thing and far less supported. The grade depends entirely on how it's used.

My experience (n=1, not proof): This one I'd grade myself as much as the compound, because I didn't give it a fair shot. I noticed a slight improvement in my skin, complexion looked a touch better, nothing dramatic. The catch: I only stayed consistent about three months, and the skin studies don't even measure until twelve weeks in. So I bailed right around when results are supposed to show. That's on me, not the molecule. If I run it again I'll commit to six months and track it with photos instead of vibes.

A "triple agonist" (GIP, GLP-1, and glucagon receptors). The next generation past Ozempic and Mounjaro. Still investigational.

Claimed: major weight loss, beyond what current GLP-1 drugs deliver.

What the evidence shows: 🟡 Moderate and climbing fast, this one genuinely has the human data. Eli Lilly's Phase 3 program (2026) reported average weight loss around 28% at the 12mg dose over 48 weeks, up to ~30% in longer extensions, the strongest numbers in the class. Not yet FDA-approved (still in trials as of mid-2026), so anyone using it now is using an investigational compound outside the trial setting.

My experience (n=1, not proof): My wife and I tried this one together, a rare two-person read. And I'll give it this: it works, the weight comes off, the trial numbers aren't lying. But I didn't like how I felt the whole time. The closest I can get is that it felt like my body was being overridden rather than supported, like the appetite signal got switched off at the mains. My wife described it almost the same way without me prompting. We both stopped and neither of us would run it again. Not a takedown: the science is impressive and for plenty of people the trade is worth it. It just wasn't for me. A compound can work and still be the wrong fit for your body, and knowing the difference is the whole point of paying attention.

A melanocortin agonist. The "tanning peptide."

Claimed: darken skin without sun, and (separately) boost libido.

What the evidence shows: 🟠 Early on effects, and this is one where safety matters more than the claims. It does cause tanning, that's real. But it's never been approved for human use, nausea hits a majority of users, and the serious concern is skin: it can darken existing moles and trigger new ones, with case reports of melanoma during or after use. No proven causation, but enough signal that dermatologists call for baseline and ongoing skin checks. The libido claim comes from its approved cousin (bremelanotide / PT-141); for Melanotan II it's secondary.

My experience (n=1, not proof): The one I regret trying, and I'll be blunt. It works, I turned dark. But I didn't like how I looked, and liked how I felt even less. The nausea was significant, a sit-with-you kind of sick. It's marketed as a libido boost and I genuinely can't report on that because I felt too rough to notice. I got the effect I cared about least and a side effect I couldn't ignore. Knowing what I now know about the mole and skin-cancer monitoring it calls for, this is the clearest risk-to-reward that didn't make sense for me. I won't run it again, and I'm including it precisely because I wouldn't. The no's are as honest as the yeses.

If you remember one thing: the peptide with the strongest human evidence here (tesamorelin) is also the most boring-sounding one, and several of the most hyped rest almost entirely on animal data. That inversion is the pattern. Be most skeptical exactly when the marketing is most confident.

And the supply problem sits underneath all of it: most of these are unapproved, so people buy them from gray-market vendors with no quality control. The FDA's advisory committee votes July 23-24 on returning several (including BPC-157 and TB-500) to legal compounding. If that happens, the conversation shifts from "what's in this vial?" to "what does the data actually say?", which is the conversation worth having.

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Educational content, not medical advice. I'm a game designer reporting studies and my own n=1, not a doctor. Talk to yours before changing anything.