When does a wound need a doctor, not a peptide?
Peptides don't replace antibiotics. A wound that's red, hot, swelling or spreading, one with pus or a red streak running away from it, or any wound that comes with a fever, needs a doctor before it needs anything from a vial. Infections can move fast, and antibiotics are the tool that works.
Everything below is about the slower stuff: the scrape that's taking its time, the scar you'd like to soften, the healing after a procedure, and the general wish to get sick less often. That's where people reach for peptides, and where the evidence gets interesting.
Are you trying to heal faster or fight off a bug?
These are two different jobs, and the six peptides people search for split cleanly between them. Healing peptides help tissue rebuild, with new skin, new blood vessels and collagen laid down where the damage was. Immune peptides work on the defense side, either nudging the immune system or attacking germs directly.
Mixing them up is how people end up buying an anti-inflammatory and expecting it to clear an infection. Pick the job first, then the peptide, and you'll know what you're actually testing.
Does GHK-Cu help wounds heal?
GHK-Cu, the copper peptide, has the strongest support of the healing group. Your body makes it naturally, and levels drop with age, which is part of why it ended up in skin care long before anyone sold it in a vial. Most of the studies looked at creams and gels on skin, where it has been studied for collagen production and for helping wounds close.
That makes it the one most women meet first, often in a serum before they ever think of it as a peptide. If your interest is skin, scars or a slow-healing scrape, it's the natural starting point, and the skin and hair guide goes further on scars and skin. The full picture is on the GHK-Cu page, and amounts and mixing are on the GHK-Cu dosage page.
What about TB-500 and BPC-157?
TB-500 is a short piece of thymosin beta-4, a protein your body uses to move repair cells into a wound. The full-length protein has small human trials, as eye drops for wounds on the cornea and as a gel for slow skin wounds, and the rest of the work is in animals. The fragment sold in vials hasn't had those human trials itself, which is a fine distinction but a real one. More on the TB-500 page and the TB-500 dosage page.
BPC-157 is the one everybody talks about, and people in the community report using it for tendons, guts and stubborn injuries. The studies, though, are almost all in rats, with next to no human trials. The rats did beautifully, and they aren't taking follow-up questions. Read the BPC-157 page and the BPC-157 dosage page before you choose it, and if you're weighing the two, BPC-157 vs. TB-500 sorts them side by side.
If you're pairing these for an injury rather than skin, the combinations people use are in the recovery and injury pairings guide.
Can a peptide help your body fight infection?
Thymosin Alpha-1 is the best-studied answer. It's approved in a number of countries outside the US as Zadaxin, for hepatitis B and C, which puts it in a rare spot for a peptide sold online: a drug with a label somewhere in the world. It has also been studied as a booster alongside vaccines and in sepsis, the body-wide reaction to a severe infection.
It doesn't kill germs itself, it supports the immune cells that do. People who use it tend to talk about getting sick less often, or about immune support through a rough season, which is reported experience rather than a trial result. Start with the Thymosin Alpha-1 page and the Thymosin Alpha-1 dosage page, and if you're deciding between it and a healing peptide, see TB-500 vs. Thymosin Alpha-1.
What about LL-37 and KPV?
LL-37 is the one that actually attacks germs. It's a natural antimicrobial your skin and immune cells make on their own, and it breaks bacteria open directly. The human evidence is one small trial on venous leg ulcers, the slow sores that form on the lower legs, with LL-37 applied to the wound. Its own research is also frank that at higher amounts it can irritate healthy cells. The LL-37 page has the background, and the LL-37 dosage page covers what's known about using it.
KPV is a tiny three-piece fragment of a hormone your body uses to calm inflammation. Most of its research is in the gut, in animal studies of colitis, the inflamed colon behind a lot of gut flares, and it gets a lot of love from people with a touchy gut. It doesn't fight infection directly, it turns down the inflammation that comes with one. The KPV page and the KPV dosage page have the details.
How do you buy one without guessing?
Pick one compound for one job, and give it long enough to tell you something. Starting two at once means that if your skin heals faster or you catch fewer colds, you won't know which one to thank.
Then compare the real price per milligram, not the vial price, since vial sizes vary and a cheap-looking vial can be the expensive one. Look for a published certificate of analysis from an independent lab, and check that it matches your batch, which our COA guide walks through in a few minutes. The vendor directory shows how each shop scores on testing and history.
What can't these peptides do yet?
The gap here is size. GHK-Cu's strongest work is on skin, not deep wounds. Thymosin beta-4's human trials were small, and they tested the full protein rather than TB-500. BPC-157 and KPV live mostly in animal studies, and LL-37 has one small human trial. Thymosin Alpha-1 has the most human data, and even that is for specific diseases, not general immune support.
None of that makes them uninteresting, it just tells you where each one stands today. You can browse every compound in this area on the healing and repair and immune support goal pages.
It's sold for research, and the big human trials haven't been run yet. You knew that, it's why you're reading this and not the label.
