A prefilled pen version of Lantus is sold under the name Lantus SoloSTAR®. Lantus is taken by injection, usually just once a day. Do not inject Lantus more often than your doctor tells you to. Your doctor can show you the right way to inject Lantus with either an insulin syringe or with the Lantus SoloSTAR pen. You should inject Lantus into the fatty layer just under the skin of your abdomen, upper and outer arm, or upper and outer thigh. Some patients experience redness at the Lantus injection site. Your doctor may advise rotating Lantus injection sites from one day to the next.