Bothrocophias lojanus, also known commonly as the Lojan lancehead in English, and macanchi or macaucho in Spanish, is a species of venomous pit viper in the subfamily Crotalinae of the family Viperidae.

[3] The species is native to northwestern South America.

B. lojanus is found in Ecuador and Peru.

[1][2][4] The preferred natural habitat of B. lojanus is forest at altitudes of 1,900–3,678 m (6,234–12,067 ft).

[1] B. lojanus preys upon lizards and small rodents.