When you buy IGF-1 LR3, the certificate of analysis (COA) is the only document that tells you what is actually in the vial. Look for two numbers above everything else: purity percentage from HPLC testing, and a confirmed molecular weight from mass spectrometry. If either is missing, you have no verified product.
Peptide Purity Testing
Purity tells you what fraction of the vial’s contents is actually IGF-1 LR3 versus everything else — broken peptide fragments, leftover synthesis chemicals, or related compounds that formed during manufacturing.
For IGF-1 LR3, look for 98% purity or higher. At 98%, roughly 2 grams in every 100 grams of material is something other than IGF-1 LR3. That sounds small, but in a research context those impurities matter because you do not know what they are or how they behave.
Purity below 95% is a real problem. You are effectively working with an unknown mixture, and your results reflect that mixture, not IGF-1 LR3 specifically.
The COA should state the purity number plainly — something like "Purity: 98.4% by HPLC." If it just says "high purity" without a number, that is not a COA, it is a label.
HPLC Peptide Testing
HPLC — high-performance liquid chromatography — is the standard method for measuring peptide purity. The equipment pushes a dissolved sample through a column at high pressure. Different molecules travel through at different speeds. A detector records each one as a peak on a chart called a chromatogram.
A good COA will include the chromatogram itself, not just the summary number. The chromatogram should show one large, clean peak for IGF-1 LR3 and small or absent peaks for everything else. The area under each peak is measured and turned into a percentage — that is where the purity figure comes from.
What to look for on the HPLC report:
- A single dominant peak, not several large peaks of similar size
- The retention time (how long the main peak took to emerge) recorded
- The purity percentage calculated from peak area, not eyeballed
- The date the test was run — HPLC results from two years ago on a new batch mean nothing
IGF-1 LR3 is an 83-amino-acid peptide, which is large by research peptide standards. Large peptides are harder to synthesise cleanly, so impurity peaks are more common than in shorter peptides. That makes HPLC results especially important here.
Mass Spectrometry Peptide Testing
Mass spectrometry confirms the identity of the peptide — that what you have is actually IGF-1 LR3, not a different peptide that happens to be pure.
HPLC tells you purity. Mass spectrometry tells you what the main peak actually is.
The technique works by measuring the mass of molecules very precisely. IGF-1 LR3 has a known molecular weight of approximately 9117 Daltons (a Dalton is the standard unit for measuring molecular mass at atomic scale). The COA should report the observed molecular weight from the test, and it should match this expected value within a very small margin.
On the COA, look for:
- "Expected MW" or "Theoretical MW" alongside "Observed MW" or "Found MW"
- Values that match closely
- The ionisation method noted — ESI (electrospray ionisation) and MALDI are both acceptable for a peptide this size
If the observed mass does not match, the peptide has either been chemically altered or you have the wrong compound.
Third-Party Tested Peptides
Third-party testing means the COA comes from a laboratory that has no financial stake in the result — not the manufacturer’s own in-house lab.
This matters because an in-house lab answers to the same business that profits from a passing result. A third-party lab answers to its own accreditation and reputation.
The COA should name the testing lab. You can then look that lab up independently. Legitimate analytical labs are registered businesses with verifiable addresses, not just initials on a letterhead.
For IGF-1 LR3 specifically, a complete third-party COA will include all of the following:
| Test | What it confirms |
|---|---|
| HPLC purity | How much of the vial is IGF-1 LR3 |
| Mass spectrometry | That the main compound is actually IGF-1 LR3 |
| Amino acid analysis (optional but useful) | That the sequence is correct |
| Endotoxin / LAL test | That bacterial contamination is below accepted limits |
The endotoxin test is worth checking too. IGF-1 LR3 is synthesised using bacteria-based or cell-free methods. Bacterial remnants — called endotoxins — can contaminate the final product. The COA should show endotoxin levels within accepted research thresholds, typically expressed in EU/mg (EU stands for endotoxin unit, the standard measure).
A COA with a purity number, a matching molecular weight, a named third-party lab, and a test date under twelve months old is what you are looking for. Everything else is incomplete information.
NXT Labs products are sold strictly as research chemicals for in vitro research, laboratory testing and analytical purposes only, and are not intended for use in any human or animal application.
NXT Labs supplies research peptides for laboratory use. Browse the full range or view current Certificates of Analysis.
