CJC-1295 Testing: Purity Standards and DAC Verification

CJC-1295 Testing Basics

CJC-1295 is a growth hormone-releasing hormone (GHRH) analog. It exists in two forms: CJC-1295 without DAC (MW 3,340.76 Da) and CJC-1295 with DAC (Drug Affinity Complex, MW 3,647.93 Da). The DAC modification extends the half-life significantly. Testing must verify both the identity and which form you received.

HPLC Purity Analysis

CJC-1295 is analyzed by reverse-phase HPLC on a C18 column. Purity standards:

• ≥98% for research grade
• ≥99% for premium grade
• Below 95% indicates poor synthesis or degradation

Distinguishing CJC-1295 with and without DAC

The key testing challenge with CJC-1295 is confirming whether the DAC modification is present. The mass difference between the two forms is 307 Da, which is easily detected by LC-MS:

• CJC-1295 (no DAC): 3,340.76 Da
• CJC-1295 with DAC: 3,647.93 Da

Vendors sometimes sell the cheaper non-DAC version labeled as CJC-1295 with DAC. LC-MS testing immediately reveals this substitution.

Common CJC-1295 Testing Issues

• DAC mislabeling: Non-DAC sold as DAC. Detectable by LC-MS mass difference.
• Modified GRF 1-29 confusion: Modified GRF 1-29 is essentially CJC-1295 without DAC. Some vendors use the names interchangeably, causing confusion.
• Degradation: CJC-1295 with DAC is less stable than the non-DAC form. Store at -20°C and avoid repeated freeze-thaw cycles.