This paper reports the controlled synthesis of lipid-b-poly(dimethylaminoethyl methacrylate) copolymers from an original lipid-based chain transfer agent (CTA). The lipid-CTA is first synthesized in two steps from linseed oil and then engaged in RAFT polymerization of dimethylaminoethyl methacrylate (DMAEMA), leading to well-defined copolymers. Self-assemblies of the resulting pH- and thermosensitive copolymers are then thoroughly investigated to determine the critical micellar concentrations and cloud point temperatures at different pH. The ability of the lipid-b-PDMAEMA micelles to load and release progesterone in various external conditions is also reported. Finally, the physical blending of this copolymer with a lipid-b-poly(2-isopropyl-2-oxazoline) copolymer, towards the formation of micellar systems with a mixed corona, is investigated.