Database from pre-1995 compilations of L x-ray production and ionization by protons is enlarged by 53% with the present update. Semiempirical formulas for L γ and L αβ are developed and used to extract L 1 , L 2 , and L 3 subshell ionization cross sections. The extracted ionization cross sections are shown for a sample of elements and compared with the database ionization cross sections in gold.