What a clean GH-peptide COA looks like — purity, identity, and the acetate question

GH peptide quality is somewhat easier to verify than GLP-1 peptide quality because the molecules are smaller and the synthesis is more straightforward. That said, this category has its own specific quality issues — most notably the GHRP-2-being-sold-as-ipamorelin substitution and the acetate-content question that affects most peptides in this class. This thread covers what to demand on a GH-peptide COA.

The basics still apply.
The general COA-reading skills covered in the COA & Lab Results category apply here. HPLC purity, mass spectrometry confirmation of identity, named accredited third-party lab, specific batch number matching the vial. If those basics are not present, do not buy regardless of category. This thread covers the additional considerations specific to GH peptides.

Acceptable purity thresholds for this category.
For research-grade GH peptides, HPLC purity above 97% is the minimum acceptable threshold. Above 98% is good. Above 99% is excellent. The category-specific consideration is that some compounds in this class are particularly sensitive to specific impurity profiles. CJC-1295-with-DAC syntheses can produce truncated versions that lack the DAC moiety — these would still show as "CJC-1295" on a basic HPLC analysis but would have the half-life of the without-DAC version. Mass spec confirmation of the full molecular weight (including the DAC modification) catches this.

The acetate question.
This is specific to peptides synthesized via solid-phase peptide synthesis (SPPS) — which is most peptides in this category. The synthesis process produces the peptide as a salt, typically the acetate salt (TFA salt is also common but less desirable for research applications because trifluoroacetate has its own toxicity considerations). The acetate content of a peptide product is typically 5-15% by mass.

What this means in practice: a 5mg vial of "ipamorelin" labeled by total mass might contain 4.25-4.75mg of the actual peptide and the rest as acetate salt. This is normal and expected — but it's relevant to dose calculations because the active peptide content is what matters pharmacologically, not the total mass.

A high-quality COA will report either the acetate content explicitly (allowing the buyer to back-calculate active peptide mass) or report the active peptide content directly (the "net peptide content"). Vendors who do not report this and just sell by total mass are being technically honest but providing less useful information for accurate research dosing.

Mass spectrometry expectations for this category.

• Ipamorelin: theoretical molecular weight 711.85 Da (5 amino acids, very small)
• GHRP-2: theoretical molecular weight 817.98 Da
• GHRP-6: theoretical molecular weight 873.02 Da
• Hexarelin: theoretical molecular weight 887.04 Da
• CJC-1295 without DAC (Mod GRF 1-29): theoretical molecular weight 3367.85 Da (29 amino acids)
• CJC-1295 with DAC: theoretical molecular weight 3647.96 Da (the DAC adds approximately 280 Da)
• Sermorelin: theoretical molecular weight 3357.92 Da (29 amino acids)
• Tesamorelin: theoretical molecular weight 5135.81 Da (44 amino acids plus modification)
• MK-677 (ibutamoren): theoretical molecular weight 528.66 Da (small molecule, not a peptide)

The mass spec value on the COA should match the theoretical weight for the labeled compound within a narrow margin. The CJC-1295 with-DAC versus without-DAC distinction is the most common point where buyers get fooled — the without-DAC version is cheaper to synthesize, and a vendor labeling without-DAC product as "CJC-1295 with DAC" is committing a substitution that mass spec catches immediately.

The ipamorelin substitution problem.
Ipamorelin is the most expensive ghrelin mimetic to synthesize because of its specific structural requirements that produce the cortisol/prolactin selectivity. GHRP-2 is significantly cheaper. A common substitution is selling GHRP-2 labeled as ipamorelin — buyers experience GH release effects but also experience the cortisol elevation, prolactin elevation, and (in some cases) hunger that ipamorelin specifically does not produce. The Red Flags thread covers detection in more detail; on the COA side, mass spec catches this trivially since the molecular weights differ by over 100 Da.

Endotoxin testing.
For injectable research, endotoxin levels should be reported with a value below the standard threshold (less than 5 EU/mg). Ghrelin mimetics and GHRH analogs are typically used in subcutaneous injection volumes of less than 1 mL, so endotoxin per dose is well below pyrogenic thresholds even at higher concentrations — but the testing presence signals overall vendor quality.

What a strong GH-peptide COA looks like in practice.
Specific batch number matching the vial. HPLC purity above 97% with chromatogram showing one dominant peak. Mass spectrometry confirming the theoretical molecular weight (with the DAC distinction explicit for CJC-1295). Acetate content reported, or net peptide content reported directly. Endotoxin testing below threshold. Named accredited third-party lab with verifiable report number.

Red flags specific to this category.

• Mass spec value matching CJC-1295 without DAC when product is labeled "CJC-1295 DAC" or "CJC-1295 with DAC"
• Mass spec value matching GHRP-2 when product is labeled "ipamorelin"
• No acetate content or net peptide content reported (less useful documentation, may indicate lower vendor quality standards)
• Identical purity numbers across multiple batches (suggests COA recycling)

If you are evaluating a vendor for any GH peptide, request the COA before ordering and verify the mass spec matches the expected molecular weight for the specific compound (and specific variant, in the case of CJC-1295). Post questions or specific COAs in the Quality and COA discussion threads if you want a second pair of eyes.