Frequently Asked Questions

A COA is basically the peptide's report card. It tells you what's in the vial, how pure it is, and whether the supplier actually tested it or just slapped a number on a PDF. Here's what to look for:

• Peptide identity — this comes from mass spectrometry (MS). The observed molecular weight should land within ±1 Da of the theoretical weight. If it doesn't, you might be looking at the wrong peptide entirely, or a truncated sequence.
• Purity — measured by HPLC and reported as a percentage. For research-grade, you want to see ≥95%. For GMP-grade, expect ≥98%. Anything below 95% and you should be asking questions.
• Amino acid sequence — usually verified by MS/MS fragmentation. Some older labs still use Edman degradation, which is fine but less common these days.
• Appearance — should read something like "white to off-white lyophilized powder." If a COA skips this entirely, that's lazy documentation at best.
• Endotoxin levels — this one matters a lot for anything injectable. Measured in EU/mg. If endotoxin data is missing on a product marketed for research injection protocols, walk away.
• Residual solvents — should be within ICH Q3C limits. This tells you the manufacturer actually cleaned up after synthesis.

Here's the thing most people miss: check whether the COA actually names the testing laboratory. A surprising number of COAs floating around online don't. No lab name, no method details, no batch number? That's not a COA — that's a marketing document.

This is one of the most important distinctions in the peptide world, and it's also one of the most misunderstood.

Research-grade peptides are made for lab use. They'll typically hit ≥95% purity by HPLC, and they're synthesized without the regulatory framework that governs pharmaceutical manufacturing. That doesn't mean they're bad — plenty of good science happens with research-grade material. But there's no regulatory body auditing the facility or verifying their documentation.

GMP-grade peptides are a different animal. GMP stands for Good Manufacturing Practice, and it means the facility has been audited and certified by a regulatory agency — the FDA in the U.S., EMA in Europe, or MFDS in Korea. Every batch is documented end to end: raw material traceability, validated synthesis processes, environmental monitoring, endotoxin testing, sterility assurance. The paperwork alone for a single GMP batch would fill a binder.

The price difference reflects this. GMP-grade peptides typically cost 5× to 20× more than research-grade. That premium isn't markup — it's the cost of infrastructure, compliance staff, and third-party audits. If a supplier is offering "GMP-grade" at research-grade prices, ask to see their facility audit report. You probably won't get one.

Bottom line: for any application that touches a human body, GMP is the standard. Full stop.

Don't just glance at the purity number and move on. That number is only useful if you understand what's behind it. Here's how to actually evaluate it:

1. Look at the HPLC method, not just the result. The COA should tell you the column type (usually reverse-phase C18), the mobile phase, and the detection wavelength (typically 220 nm). A single clean dominant peak at ≥95% area is what you're looking for. Multiple peaks or a broad baseline? That's impurities or degradation products the supplier may not be flagging.
2. Cross-check with mass spec. The observed molecular weight from MS should match the theoretical weight for the peptide sequence you ordered. If the mass is off, it could mean you received a truncated peptide, a deletion sequence, or something else entirely. This happens more often than people realize.
3. Who did the testing? A credible COA names the analytical laboratory. If it says "tested in-house" with no lab name and no analyst signature, the data is only as trustworthy as the supplier's honesty. That's a lot of trust to extend to someone you've never met.

If you really want to be sure, send a sample out yourself. Any decent analytical lab with HPLC and LC-MS capability can run identity and purity for around $150 to $400 per sample. It's not cheap, but it's a fraction of what you'd lose on a bad batch. We think independent verification should be standard practice, and it's a big part of why we built KORECOA.

BPC-157 — Body Protection Compound-157 — is probably the most talked-about research peptide of the last decade. It's a 15-amino-acid synthetic peptide (sequence: Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val) that was originally isolated from a protein found in human gastric juice.

The research interest is mostly around repair and recovery. In animal models — primarily rodents — published studies have looked at BPC-157's effects on wound healing, tendon and ligament repair, gut mucosal protection, and angiogenesis (the formation of new blood vessels). Some of the more cited findings include accelerated healing of muscle tears, tendon transections, and bone fractures, plus protective effects against NSAID-induced stomach damage.

That said, it's important to be clear about what this is and isn't. BPC-157 is a research peptide. It has not been approved by the FDA or any other regulatory agency for human therapeutic use. It's not a drug. The published evidence is preclinical — animal studies and in vitro work, not large-scale human clinical trials. The peptide community sometimes gets ahead of the science on this one.

Researchers source BPC-157 as a lyophilized powder that needs to be reconstituted with bacteriostatic water before use. Purity and sourcing matter here — this is one of the most commonly counterfeited peptides on the market.

These two get compared constantly because they both show up in "recovery stack" discussions, but they're actually quite different peptides doing different things.

BPC-157 is small — just 15 amino acids, about 1,419 Da. It comes from a gastric protein, and the research leans heavily toward localized repair: tendons, ligaments, muscles, gut lining. The proposed mechanisms involve angiogenesis (growing new blood vessels into damaged tissue), nitric oxide pathways, and upregulating certain growth factors. Most of the published work focuses on specific injury sites.

TB-500 is bigger — 43 amino acids, roughly 4,963 Da. It's a synthetic fragment of Thymosin Beta-4, which is a protein your body naturally produces that's involved in cell migration and tissue repair. The research here tilts more systemic: reducing inflammation broadly, promoting cell migration to injury sites, and supporting cardiac and skin tissue repair. Think of it as more of a whole-body signal rather than a targeted repair compound.

Some researchers have looked at combining the two — the idea being that BPC-157 handles localized repair while TB-500 provides systemic anti-inflammatory support. That's an interesting hypothesis, but neither peptide has been approved for human use, and the combination research is still early-stage.

From a sourcing perspective, TB-500 is generally more expensive per milligram because of its longer sequence and higher synthesis complexity.

Most peptides ship as a lyophilized (freeze-dried) powder. In that form, they're surprisingly stable — you can ship them at room temperature without much worry. But once they arrive, how you handle them matters a lot.

Reconstitution — do it slowly.

1. Let the vial come to room temperature first. Don't rush this.
2. Use bacteriostatic water (BAC water) — it contains 0.9% benzyl alcohol, which inhibits microbial growth and gives you a longer usable window than sterile water.
3. Run the solvent down the inside wall of the vial. Don't blast it directly onto the powder cake — that can cause foaming and denaturation.
4. Swirl gently. Never shake. If you've ever seen someone vigorously shake a peptide vial, that's how you get foam and degraded product.

Storage — temperature is everything.

• Unreconstituted (powder): -20°C freezer for long-term storage. If you'll use it within a few weeks, the fridge (2–8°C) is fine.
• Reconstituted (in solution): Always refrigerate at 2–8°C. Use within 21 to 28 days. After that, purity starts to drop.
• The big mistake: Repeatedly freezing and thawing the same vial. Every freeze-thaw cycle damages the peptide. If you need to store reconstituted peptide longer, aliquot it into smaller portions before freezing.

One more thing — not every peptide dissolves easily in water. Hydrophobic peptides might need a small amount of DMSO or dilute acetic acid first, then dilution with water. If the powder isn't dissolving after gentle swirling, don't force it. Check the manufacturer's solubility notes for that specific sequence.

Lyophilized just means freeze-dried. It sounds more complicated than it is, but the process is actually quite elegant and it's the reason peptides can be shipped around the world without losing their potency.

Here's how it works in three stages:

1. Freezing — the peptide solution gets frozen solid.
2. Primary drying — the chamber pulls a vacuum, and the frozen water sublimates — it goes directly from ice to vapor without passing through a liquid phase. This is the clever part.
3. Secondary drying — a slight temperature increase drives off any remaining bound moisture.

What you're left with is that white or off-white powder (sometimes called a "cake" or "puck") sitting at the bottom of the vial. It looks fragile, but it's actually the most stable form of the peptide. Water is the enemy of peptide stability — it promotes hydrolysis and other degradation reactions. Remove the water, and a peptide stored at -20°C can last for years without meaningful loss of activity.

Once you add water back (reconstitution), the clock starts ticking again. The peptide is active but degrading slowly. That's why reconstituted peptides have a shelf life measured in weeks, not years.

If you've heard of Ozempic, Wegovy, or Mounjaro, you've already encountered GLP-1 receptor agonists — they've become some of the most prescribed drugs in the world.

GLP-1 stands for Glucagon-Like Peptide-1. It's a hormone your body naturally makes after you eat. It tells your pancreas to release insulin, tells your liver to ease off on glucagon production, slows down your stomach emptying so you feel full longer, and signals your brain that you've had enough food. The problem is, natural GLP-1 breaks down in minutes.

GLP-1 receptor agonist drugs are engineered peptides that mimic this hormone but last much longer in the body. Semaglutide (the molecule behind Ozempic and Wegovy) has a half-life of about a week, which is why it's dosed weekly. Tirzepatide (Mounjaro, Zepbound) goes a step further — it hits both GLP-1 and GIP receptors, which is why some studies show even stronger weight loss and glycemic effects.

These are FDA-approved pharmaceutical products manufactured to strict GMP standards. The active pharmaceutical ingredients (APIs) are peptides, synthesized at massive scale by companies with significant regulatory infrastructure.

Research-grade GLP-1 peptide APIs are available from synthesis companies for investigational use. But it's critical to understand: these are raw materials, not finished drugs. They haven't gone through the formulation, fill-finish, and quality release processes that a pharmaceutical product requires. They're not interchangeable with the branded medications, and they're not approved for human use.

This is where most people get burned. The peptide supplier market is full of middlemen, relabelers, and outright frauds sitting next to legitimate manufacturers and specialty distributors. Here's how to tell the difference:

1. Ask for a batch-specific COA before you buy. Not a "sample COA" from their website — an actual COA for the batch they're about to ship you. It should show HPLC purity, mass spec confirmation, and name the testing laboratory. If they hesitate, that tells you something.
2. Find out if they support third-party testing. The best suppliers will either use an independent analytical lab themselves or actively encourage you to verify their product independently. If a supplier gets defensive when you mention third-party testing, that's a red flag.
3. Ask about the facility. Are they manufacturing in-house or sourcing from a contract manufacturer? Do they follow GMP, ISO, or any quality framework? For research-grade, ISO or equivalent is a reasonable bar. For anything involving human exposure, you need GMP — and you should be able to see the certificate.
4. Look for regulatory documentation. Serious suppliers can provide Drug Master File (DMF) numbers, facility audit reports, or at least a detailed description of their QC process. If all they have is a website with stock photos and a Telegram channel, keep looking.
5. Check the track record. How long have they been in business? Can they point to published research that used their material? Do they have verifiable customer reviews — not just testimonials on their own site?

The warning signs are consistent: no verifiable physical address, no named quality contact, pricing that's dramatically below everyone else (cheap peptides are cheap for a reason), and COAs that look identical across completely different peptides and batches. If the COA for their BPC-157 and their semaglutide have the same formatting, same layout, and suspiciously similar numbers — someone is generating documents, not testing product.

Nearly all commercial peptides today are made using Solid-Phase Peptide Synthesis, or SPPS. The technique was developed by Robert Bruce Merrifield in the 1960s — he won the Nobel Prize for it in 1984 — and it remains the backbone of the industry.

The idea is straightforward: you anchor the first amino acid to an insoluble resin bead, then build the peptide chain one amino acid at a time, working from the C-terminus to the N-terminus. Each cycle has three steps:

1. Deprotection — you remove a chemical protecting group from the last amino acid on the chain, exposing it for the next coupling.
2. Coupling — the next amino acid in the sequence is activated and bonded to the growing chain.
3. Washing — excess reagents and byproducts are flushed away.

Repeat until the full sequence is assembled. Then you cleave the finished peptide off the resin and purify it — typically by reverse-phase HPLC, which separates the target peptide from truncated sequences, deletion peptides, and other synthesis byproducts.

The two dominant chemistries are Fmoc and Boc. Fmoc (fluorenylmethyloxycarbonyl) is the standard in modern labs because it uses milder conditions — no hydrofluoric acid required, unlike Boc chemistry. Most automated synthesizers run Fmoc protocols.

At the GMP manufacturing level, the process is the same chemistry but with enormously more documentation, validation, and quality control. Every step is monitored. Every batch is tested by HPLC, mass spectrometry, amino acid analysis, and endotoxin assay before it gets a release certificate. The difference between a research lab synthesizing 50mg and a GMP facility producing 5kg isn't just scale — it's an entirely different level of process control and accountability.