Tutupaca consists of two volcanic complexes: an older complex that is highly eroded, and two northerly peaks which formed more recently. Of these, the eastern peak (eastern Tutupaca) consists of several presumably Holocene lava domes and is high, while the western one (western Tutupaca) consists of lava domes, lava flows and Plinian eruption deposits of Pleistocene age, and reaches a height of . The Global Volcanism Program gives heights of for the eastern and for the western summit. The western peak is the highest summit of Tutupaca.