A thermogelling, aliphatically modified polymer for use in drug delivery is described. Illustrative embodiments include poly(lactic-co-.epsilon.-caprolactone)-poly(ethylene glycol)-poly(lactic-co-.epsilon.-caprolactone) hexanoate and poly(lactic-co-.epsilon.-caprolactone)-poly(ethylene glycol)-poly(lactic-co-.epsilon.-caprolactone) laurate. Another illustrative embodiment includes a composition having a thermogelling amount of an aliphatically modified poly(lactic-co-.epsilon.-caprolactone)-poly(ethylene glycol)-poly(lactic-co-.epsilon.-caprolactone) and an effective amount of a drug. The thermogelling polymers are made by bonding an aliphatic group to poly(lactic-co-.epsilon.-caprolactone)-poly(ethylene glycol)-poly(lactic-co-.epsilon.-caprolactone). A method of use includes injecting a warm-blooded individual with a thermogelling amount of the aliphatically modified polymer and a drug.