Certificate PL-26-00281 · Retatrutide 20 mg · lot PL-2610-168
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PrymaLab
PrymaLab Analytical · In-house laboratory
3705 Music Branch Rd, Ashland, KY 41102 · +1 (606) 465-9063 · prymalab.net
Certificate no.
PL-26-00281
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GWMLVVY8
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Certificate of Analysis · Lot release

Retatrutide 20 mg

Lot PL-2610-168 · Lyophilized powder · Label claim 20 mg per vial
Tested in-house by PrymaLab
In-house analytical result,
not an independent third-party test
Lot / batch number
PL-2610-168
Date made
2026-10-06
Date of analysis
2026-10-07
Date issued
2026-10-21
Retest / expiry
2028-10-06
Units in lot / sampled
211 / 2
Storage
−20 °C, desiccated, dark
Certificate type
Lot COA, 2 pages
Compound
Retatrutide
LY3437943; GIP/GLP-1/glucagon receptor triple agonist
CAS number
2381089-83-2
Molecular formula
C221H342N46O68
Theoretical mass (avg.)
4,731.33 Da
Sequence
acylated tri-agonist
Purity · RP-HPLC, area %
99.51%
Specification ≥ 99.0% • main peak at 18.49 min
Identity · Observed Mass
4,731.10 Da
Theoretical 4,731.33 Da • −0.23 Da (49 ppm)
Overall conclusion
PASS
Meets every specification for the tests performed
TestMethodSpecificationResultConclusion
Identity (mass)LC-MS, ESI positiveTheoretical ± 1.0 Da4,731.10 DaPASS
PurityRP-HPLC, UV 214 nm, area%≥ 99.0%99.51%PASS
Largest impurityRP-HPLC, area%≤ 1.0%0.27% (RT 19.60)PASS
Water contentKarl Fischer≤ 5.0%2.71%PASS
Bacterial endotoxinLAL, kinetic≤ 5.0 EU/mg0.259 EU/mgPASS
SterilityUSP <71>, 14-dayNo growthNo growthPASS

1HPLC chromatogram

Data file: PL-2610-168-HPLC.raw · Column C18, 150 × 4.6 mm · UV 214 nm
0.01%0.1%1%10%100%161718192021Retention time (min) · stick height = area % (log scale)99.51% · 18.49 min0.11% †0.11% †0.27% †
Peak plot drawn from the integrated peak table (area %, log scale); it is not the instrument trace, which is retained in PL-2610-168-HPLC.raw. † Nominal reference retention time for the assigned impurity; the main-peak RT is observed in this lot.
PrymaLab
PrymaLab
Certificate of Analysis · continued
Retatrutide 20 mg · Lot PL-2610-168 · Certificate PL-26-00281
Lot PL-2610-168
Method, peak table and approval

2HPLC method · PL-2610-168-HPLC.raw

Instrument
Waters Alliance e2695
Data System
Empower 3
Detector
UV absorbance
Detection Wavelength
214 nm
Column
C18, 150 × 4.6 mm, 3.5 µm
Mobile Phase A
0.1% TFA in water
Mobile Phase B
0.1% TFA in MeCN
Gradient
5–95% B over 25 min (linear)
Flow Rate
1.0 mL/min
Column Temperature
40 °C
Injection Volume
10 µL

3Gradient program

Time (min)% A% B
0.0955
25.0595

4Peak table

PeakRT (min)AreaArea %
117.00 †—0.11
217.80 †—0.11
318.49—99.51
419.60 †—0.27
Total—100.00
Peaks: 1 deamidation product; 2 isoaspartate (isoasp) variant; 3 main peak (Retatrutide); 4 tryptophan oxidation product · Area % from the integrated peak table (absolute areas are not part of the lot-release export) · † nominal reference RT for the assigned impurity · Purity = main peak area ÷ total integrated area × 100, to two decimals; main peak shaded.

5Identity by mass spectrometry

Instrument
Waters SQD
Ionization / Mode
ESI, positive
Reference m/z (charge)
1183.84 (4+) · 947.27 (5+)
Deconvoluted Mass
4,731.10 Da
Theoretical Mass
4,731.33 Da
Difference
−0.23 Da (49 ppm)
Data File
PL-2610-168-MS.d
Acceptance
Within ± 1.0 Da

6Additional tests

TestPerformed byDateReport / file
Water content (Karl Fischer)PrymaLab Analytical2026-10-07—
Endotoxin (LAL, kinetic)PrymaLab Analytical2026-10-07—
Sterility (USP <71>, day-14 read-out)PrymaLab Analytical2026-10-21—
A test with no row here was not performed on this lot. Outside-laboratory reports, when used, are attached and named below.

7Review and approval

D. Reynolds
Analyst · performed the testing
Date: 2026-10-21
S. Calloway
Reviewer · checked against raw data
Date: 2026-10-21
M. Phelps
Lab Director · approved for release
Date: 2026-10-21