Laboratory results, batch by batch

The header says which material it is, which batch and when it was produced. Before you look at any number, confirm these details.

• NameName
  Value: Retatrutide

  The material tested: retatrutide, the active ingredient of the pen, as raw material.

• CAS numberCAS No.
  Value: 2381089-83-2

  International code that identifies a chemical substance. It lets you check that two documents describe the same compound.

• Molecular formulaMolecular Formula
  Value: C221H342N46O68

  How many atoms of each element make up the molecule. It describes the composition of a molecule, not the quantity of material.

• Molecular weightMolecular Weight
  Value: 4731.33

  Theoretical mass of the molecule. It is the reference the measured mass is compared with in phase 2.

• Batch numberBatch No.
  Value: R20260318

  Ties this paper to a specific quantity of material. Another batch has its own analysis and its own results.

• StorageStorage
  Value: -20 °C

  Temperature at which the raw-material powder was kept. It is not the storage of the finished pen, which is 2 to 8 °C.

• PurityPurity
  Value: 99.38%

  Of what the method detected, how much is the right molecule. A round 100% almost never appears, because every method has a detection limit.

• AppearanceCharacter
  Value: White powder

  Visual description of the material: white powder.

• Production dateProduction date
  Value: 2026.03.18

  When the batch was produced. It is not the expiry date, and one does not replace the other.

• Production sizeProduction Size
  Value: 1.8 kg

  Total quantity of raw material in this batch. It is not the contents of a pen.

Each row compares the batch result with the limit set before the analysis: reading means checking that the result falls within what was expected. These lines also show why purity and peptide content are different numbers.

• Water contentWater Content (K.F)
  Specification: ≤8.0%Result: 4.6%

  Water held in the powder, measured by the Karl Fischer (K.F) method. The batch came in below the limit.

• Acetic acidAcetic Acid
  Specification: ≤0.5%Result: N.D.

  A possible trace from purification. N.D. means “not detected”: the method did not find it above its detection limit.

• SodiumSodium Content
  Specification: ≤5.0%Result: 2.1%

  Sodium bound to the peptide as a salt. Together with water, it explains why the powder is not 100% peptide.

• MassMass
  Specification: 4731.35Result: Confirms

  Mass of the main component, measured in the laboratory. “Confirms” means it matches the mass expected for retatrutide and supports the identity of the material.

• pHpH
  Specification: 6.0-9.0Result: 7.6

  Shows whether a solution of the material is more acidic or more alkaline. The result is within the expected range.

• Peptide contentPeptide Content
  Specification: ≥85%Result: 90.8%

  Of all the powder that was weighed, how much is peptide; the rest is mostly water and salts. That is why it differs from purity.

• Residual solventsResidual Solvent
  Specification: ≤410 · ≤5000 · ≤600 · ≤720 · ≤880 ppmResult: 126 ppm · ND · ND · ND · ND

  Liquids that may have been used in production and purification; there are five: acetonitrile, ethanol, dichloromethane, tetrahydrofuran and dimethylformamide. ppm means parts per million; ND, not detected. Only acetonitrile appeared (126 ppm, below its limit); the other four came out ND.

The last part shows what the process may have left behind and closes with the split between the main molecule and impurities. The full document, with the laboratory’s signatures and seal, is in the PDF.

• Total microorganismsMicrobial Limits (TAMC)
  Specification: ≤100 cfu/gResult: <20 cfu/g

  Total count of aerobic microorganisms per gram (cfu/g: colony-forming units). The “<” sign means the result fell below 20, and the limit is 100.

• Yeasts and mouldsMicrobial Limits (TYMC)
  Specification: ≤100 cfu/gResult: <20 cfu/g

  Total count of yeasts and moulds, read the same way as the line above.

• Bacterial endotoxinsBacterial Endotoxins
  Specification: <10 EU/mgResult: Conforms

  Fragments of the wall of certain bacteria. “Conforms” means the result is in line with the limit of less than 10 EU/mg.

• Total impuritiesTotal impurities
  Specification: ≤1.0%Result: 0.62%

  Everything detected that is not the main molecule. Added to the purity it makes 100% (0.62 + 99.38).

• Largest individual impurityMaximum Single impurity
  Specification: ≤0.5%Result: 0.20%

  Helps tell apart two situations that look alike in the total: many tiny impurities or a single one that stands out.

• Principal componentPrincipal Component
  Specification: ≥98.0%Result: 99.38%

  The molecule being sought. It repeats the purity figure from phase 1 and compares it with its minimum of 98.0%.