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Documented Purity vs Advertised Concentration Claims
Real Peptides provides a Certificate of Analysis (CoA) with every Follistatin-344 order, documenting HPLC-verified purity, mass spectrometry-confirmed molecular weight, and endotoxin testing results. The CoA is batch-specific. The document you receive correspo
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- Real Peptides provides a Certificate of Analysis (CoA) with every Follistatin-344 order, documenting HPLC-verified purity, mass spectrometry-confirmed molecular weight, and endotoxin testing results. The CoA is batch-specific. The document you receive corresponds to the exact synthesis run your vial came from, not a representative sample from months earlier. Competitors offering CoAs often provide one document for an entire product line, not per-batch verification.
- Advertised concentration (e.g., "5mg Follistatin-344 per vial") is meaningless without purity context. A vial labeled 5mg at 80% purity contains 4mg active peptide plus 1mg impurities, truncations, and synthesis byproducts. A vial labeled 5mg at ≥98% purity contains 4.9mg active peptide. Dosing studies using the first vial would require 22.5% more material to match the bioactivity of the second. But researchers typically dose by labeled concentration, not verified purity-adjusted mass. This is how published studies using "identical" peptides report conflicting efficacy.
- Endotoxin contamination is another unspoken variable. Bacterial endotoxins from E. coli expression systems or reagent contamination trigger immune responses in cell cultures and animal models. Confounding results in inflammation studies, cytokine research, and immune modulation experiments. Real Peptides conducts LAL (Limulus Amebocyte Lysate) endotoxin testing and certifies <1 EU/mg. Many competitors don't test for endotoxins at all or use thresholds permissive enough to pass crude preparations that would be rejected under pharmaceutical-grade standards.