PrymaLab

PrymaLab Analytical · In-house laboratory

3705 Music Branch Rd, Ashland, KY 41102 · +1 (606) 465-9063 · prymalab.net

Certificate no.

PL-26-00352

Verification key

4BCUGDBJ

Scan or enter both at
prymalab.net/testing/verify

Certificate of Analysis · Lot release

YK-11 5 mg Capsules

Lot PL-2610-239 · Capsules · Label claim 5 mg per capsule

Tested in-house by PrymaLab

In-house analytical result,
not an independent third-party test

Lot / batch number

PL-2610-239

Date made

2026-10-08

Date of analysis

2026-10-09

Date issued

2026-10-15

Retest / expiry

2028-10-08

Units in lot / sampled

342 / 2

Storage

—

Certificate type

Lot COA, 2 pages

Compound

YK-11

YK11, steroidal SARM / myostatin inhibitor

CAS number

1370003-76-1

Molecular formula

C₂₅H₃₄O₆

Theoretical mass (avg.)

430.53 Da

Structure

Purity · RP-HPLC, area %

99.80%

Specification ≥ 99.0% • main peak at 13.20 min

Identity · Observed Mass

430.54 Da

Theoretical 430.53 Da • +0.01 Da (23 ppm)

Overall conclusion

PASS

Meets every specification for the tests performed

Test	Method	Specification	Result	Conclusion
Identity (mass)	LC-MS, ESI positive	Theoretical ± 1.0 Da	430.54 Da	PASS
Purity	RP-HPLC, UV 254–306 nm, area%	≥ 99.0%	99.80%	PASS
Largest impurity	RP-HPLC, area%	≤ 1.0%	0.13% (RT 14.10)	PASS
Capsule content	Content vs label claim	4.5–5.5 mg/cap	5.07 mg/cap	PASS
Bacterial endotoxin	LAL, kinetic	—	—	N/A
Aerobic count (TAMC)	USP <61>	< 10 CFU/g	< 10 CFU/g	PASS
Yeast & mold (TYMC)	USP <61>	< 10 CFU/g	< 10 CFU/g	PASS
E. coli	USP <62>	Absent	Absent	PASS

1HPLC chromatogram

Data file: PL-2610-239-HPLC.raw · Column C18, 150 × 4.6 mm · UV 254–306 nm

Peak plot drawn from the integrated peak table (area %, log scale); it is not the instrument trace, which is retained in PL-2610-239-HPLC.raw. † Nominal reference retention time for the assigned impurity; the main-peak RT is observed in this lot.

PrymaLab

Certificate of Analysis · continued

YK-11 5 mg Capsules · Lot PL-2610-239 · Certificate PL-26-00352

Lot PL-2610-239

Method, peak table and approval

2HPLC method · PL-2610-239-HPLC.raw

Instrument

Waters Alliance e2695

Data System

Empower 3

Detector

UV absorbance

Detection Wavelength

254–306 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
0.0	95	5
25.0	5	95

4Peak table

Peak	RT (min)	Area	Area %
1	12.00 †	—	0.03
2	13.20	—	99.80
3	14.10 †	—	0.13
4	14.70 †	—	0.04
Total		—	100.00

Peaks: 1 unidentified impurity; 2 main peak (YK-11); 3 unidentified impurity; 4 unidentified impurity · 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 (ion)

431.54 [M+H]+

Deconvoluted Mass

430.54 Da

Theoretical Mass

430.53 Da

Difference

+0.01 Da (23 ppm)

Data File

PL-2610-239-MS.d

Acceptance

Within ± 1.0 Da

6Additional tests

Test	Performed by	Date	Report / file
Content vs label claim	PrymaLab Analytical	2026-10-09	—
Microbial limits (USP <61>/<62>)	PrymaLab Analytical	2026-10-15	—

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: 2026-10-15

S. Calloway
Reviewer · checked against raw data
Date: 2026-10-15

M. Phelps
Lab Director · approved for release
Date: 2026-10-15