WebFeb 25, 2015 · HUMULIN ® N (human insulin [rDNA origin] isophane suspension), injectable suspension, for subcutaneous use. Initial U.S. Approval: 1982. Recent Major Changes. Warnings and Precautions. Never Share a HUMULIN N Pen, HUMULIN N KwikPen, or Syringe Between Patients ( 5.1) 02/2015. Indications and Usage for Humulin N.