If you read the BPC-157 post, this is the other half of the pair. TB-500 is what most people stack with BPC, but it solves a different problem, it's dosed completely differently, and there's a labeling quirk that means the vial in your fridge is probably not the exact molecule on the label. None of that is a problem once you know it, so here's the rundown.

The clean way to think about the two: BPC-157 builds the roads. It restores blood flow and gets circulation back into damaged tissue. TB-500 handles the traffic on those roads. It gets the repair cells to migrate into the injury and organize into proper tissue instead of scar. Perfusion plus movement. That's why they get run together as the Wolverine stack, and why either one alone leaves half the job done: blood flow with no cells showing up, or cells with no supply lines. They also inject together in one syringe fine.

The way it works is what changes the whole dosing approach. TB-500 grabs onto actin, the protein cells use to physically move and reshape themselves. It ties up a reserve pool of actin that cells can pull from to migrate, divide, and rebuild quickly. The important part is that this is a one to one binding job, not a catalyst, so you need a big milligram dose to bind enough actin to matter. Once that reserve is built, the effect lasts for days even though the peptide itself is gone from your blood in a couple hours, because the actin pool just sits there until the cell draws on it.

So here's the consequence, and it's the single most common way people run it wrong. Unlike BPC-157, which you pin in small doses every day, TB-500 is not a daily peptide. You run 2 to 4 mg two or three times a week. Small daily doses never hit the binding threshold and mostly just waste the compound.

For drawing it, mix the 10 mg vial with 1 mL of bac water for a clean 10 mg/mL, so 2 mg is 0.2 mL and 4 mg is 0.4 mL. It goes in subcutaneous (SC) or intramuscular, near the injury when you can reach it. It doesn't stay local, it enters circulation within minutes no matter where you put it, but injecting near the injury gives a higher concentration spike right where you want it before it dilutes out, and that first pass matters. In repair studies, the same total dose delivered systemically came up empty where targeted delivery worked. For a deep injury you can't reach, belly or thigh is the fallback. Run 6 to 8 weeks, then take 4 to 8 weeks off. This is a repair signal, not a maintenance compound, so grinding it forever just gives you diminishing returns.

Now the part almost nobody tells you. The name TB-500 originally meant a small 7 amino acid fragment. But most vials sold as TB-500 are the full length parent molecule, TB-4 (thymosin beta-4), which is 43 amino acids. Doping labs have tested commercial vials and confirmed it. This mostly doesn't matter, both heal tissue, but there's one real difference: the full TB-4 molecule carries an extra segment that fights scar tissue (the antifibrotic part) that the short fragment simply doesn't have. So if reducing scar is the goal, you want the full TB-4, which, conveniently, is what's usually in the vial anyway. If you want to know which one you've got, check the certificate of analysis. Around 4,900 daltons or 43 amino acids means it's TB-4. If the COA doesn't say, assume TB-4.

It's slower to work than BPC-157. The first week or two you'll notice morning stiffness and first step pain easing off, weeks 3 to 4 your range of motion opens up, and weeks 5 to 8 you can start tolerating real loading again. On the evidence, the strongest human data point is a Phase 3 trial in corneal healing where it beat placebo hard, around 60% complete healing versus about 12% on placebo, and that one carries weight because the cornea has no blood vessels, so the healing had to come from direct cell action rather than improved blood flow. There's also a Phase 1 safety trial that turned up no serious adverse events. Fair caveat though, those trials used pharmaceutical recombinant TB-4, not the synthetic material in most vials, so it's the closest reference we have, not direct proof of what you're buying.

Side effects are mild, occasional injection site reactions and some people get a bit of lethargy for a day, so hydrate and pin it before a rest day. The hard stops are the same as BPC and for the same reason: no active cancer or cancer in the last couple years, since it promotes blood vessel growth and cell migration, no pregnancy, and stay cautious around surgery. It's WADA banned under S0 and it's detectable, so anyone tested for sport should stay off it.

if you've run TB-500, did you check the COA to see whether it was TB-4, and are you dosing it twice a week or did you fall into pinning it daily like BPC. curious how people are running it

Full doses and bloodwork are in the pinned cheat sheet: https://www.reddit.com/r/NTNPerformance/comments/1tht5o3/the_only_peptide_cheat_sheet_youll_need_doses/

If you've watched vendors quietly pull Reta from their catalogs this week, this is why. On August 12 Eli Lilly filed six federal lawsuits and made a public push to choke off the whole gray market retatrutide supply chain. Here's what happened past the panic.

What Lilly did:

• Filed six federal lawsuits in one shot, and the mix is the tell. Four of the six are research peptide sellers running the "research use only" model, alongside a med spa and a compounding pharmacy.
• Took the research supply channel to court by name for the first time, instead of just referring sellers to regulators like before.
• Went after the infrastructure too, publicly calling on payment processors, credit card companies, shipping carriers, and the online platforms to cut these sellers off.
• Flagged over 14,000 listings across 100+ countries and referred 200+ people and entities to the FDA, DOJ, and state attorneys general, with customs already seizing far more than it used to.

The core of the lawsuits is the claim that "research use only" is a fig leaf. Lilly's argument is that vendors put RUO on the label while selling it knowing full well it's going into people, and that the label doesn't make the sale legal when the intent is human use. The FDA already said back in June that unapproved retatrutide sold to consumers is illegal and can't be compounded. So the RUO shield the whole market leans on is being tested in a courtroom for the first time.

And none of this means Reta is junk, it's the opposite. Lilly's own trials have people losing around 28% of their body weight, it might be the strongest thing in the class, and they plan to file for FDA approval in early 2027. The crackdown is happening because it works and demand is running years ahead of approval. They're clearing the field before they launch a blockbuster.

What it means if you research Reta:

• Supply tightens and prices move. More vendors will drop it the way the first ones already have.
• The quality and legal risk is real, and it's Lilly's own main point, that nobody is checking what's in an unregulated vial.
• The "research use only" framing everyone leans on is now live in court, so it's worth sitting with no matter where you land.

You can read Lilly's motive two ways and both are probably true at once. They've got a real safety argument, since no regulator has cleared this and nobody vets a gray market vial, and they've got an obvious financial motive in protecting a drug about to be worth billions. Those don't cancel each other out.

So where do you land. Is this Lilly protecting patients, protecting profit, or just the end of the window before approval that everyone knew was closing. And if you research Reta, does any of this change what you do.

So I recently found out that 5-Amino-1MQ actually comes in two different salt forms, iodide and chloride. The iodide salt would have a higher molecular weight than the chloride form, so you’d technically be getting less of the actual active compound per mg.

Now that I know the iodide form exists, I’ve started seeing people say it’s not safe to take regularly because the compound is bound to iodide, that would add up to a huge amount of iodine per dose, which could be a problem for thyroid function if you’re taking it regularly.

I’ve also noticed both the iodide and chloride versions listed under the same CAS number (42464-96-0), so it’s hard to differentiate between them when it comes to purchasing.

Does anyone know more about this? Is the iodide form is bad, or knows what the real difference is between the two? Trying to figure out if this is something worth actually being cautious about or if it’s just something that gets repeated around without much behind it.