Retatrutide (LY3437943)nominal molarity calculator

01 / run from source

Python 3.10+. No dependencies.

Download the Python source or clone the repository. Run the commands from the directory containing retatrutide_stoichiometry.py. Use python3 where appropriate.

# One nominal calculation
python retatrutide_stoichiometry.py --mass-mg 10 --final-volume-ml 2

# The same result as numeric JSON
python retatrutide_stoichiometry.py --mass-mg 10 --final-volume-ml 2 --json

# Default eight-row theoretical matrix
python retatrutide_stoichiometry.py

# Run the supplied tests
python -B -m unittest discover -v

Python API

from dataclasses import asdict
from retatrutide_stoichiometry import calculate_reconstitution

result = calculate_reconstitution(mass_mg=10, final_volume_ml=2)
print(result.concentration_mg_ml)  # 5.0
print(result.molarity_mM)          # 1.0567853013846
print(result.aliquot_1mg_uL)       # 200.0
print(asdict(result))

The API returns a frozen ReconstitutionResult dataclass. Inputs must be positive, finite real numbers; invalid inputs raise ValueError. Supply both CLI input flags together. Invalid CLI input exits with status 2.

02 / calculation method

An explicit mass convention

Let m be nominal net parent peptide mass in mg and V be final solution volume in mL. Every calculation fixes MW = 4731.33 g/mol, a conventional approximate average molecular weight.

Mass concentration · mg/mL

m / V

Molarity · mM

1000 × m / (MW × V)

Molarity · μM

1,000,000 × m / (MW × V)

Total amount · nmol

1,000,000 × m / MW

Volume per nominal 1 mg · μL

1000 × V / m

Unit check: 1 mg/mL = 1 g/L. Under this convention, 4.73133 mg is 1 μmol; in 1 mL final volume, it is 1 mM. Binary floating-point output has more digits than the inputs' experimental precision warrants.

The distinct monoisotopic mass, approximately 4728.4718 Da, is reference metadata and is not used for molarity. The companion note separately distinguishes monoisotopic ESI-MS values from average-mass proxies. The chosen 4731.33 value is neither a lot-specific measurement nor an uncertainty claim.

03 / data and evidence

Two files, two evidence types

The COA compilation records source URLs, SHA-256 digests, dates and transcription status. Assay basis and measurement uncertainty were not independently established; formulation was not explicitly identified in the report text. See the data dictionary and source manifest.

04 / companion record

Cite the technical note

The OSF record is the persistent reference for the companion publication. This documentation page describes its calculation software and supporting files; it does not claim independent peer review.