An improved method for preparing squalene from a squalene-containing composition, said method comprising the steps of (a) a purification distillation carried out at a temperature T1 (b) a denaturing distillation carried out at a temperature T2; wherein steps (a) and (b) may be performed in either order; T1 and T2 are sufficient to cause squalene to boil; T2>T1; and T2>200° C.