Net peptide content refers to the actual amount of pure peptide present in a peptide sample, expressed as a percentage of the total weight. It does not include water, salts, counterions, residual solvents, or other non-peptide impurities that may be present after synthesis, purification, or lyophilization.

In simple terms:

• Gross weight = peptide + water + salts + impurities
• Net peptide content = the pure peptide portion only

For example, if a vial contains 10 mg of lyophilized peptide powder and the net peptide content is 80%, the actual amount of pure peptide is: 10 mg × 80% = 8 mg of pure peptide