Indolizidine alkaloids are natural products from various alkaloid groups whose structure can be derived from indolizidine.

Indolizidine alkaloids are present in various plant families, including Elaeocarpaceae, Asclepiadaceae, and are also produced as metabolites by fungi and bacteria. For instance, Slaframine and swainsonine were identified in the fungus Rhizoctonia leguminicola, while Castanospermine was extracted from Castanospermum australe. Notably, this alkaloid group includes pumiliotoxins, which are the toxins of the strawberry poison-dart frog.

The polyhydroxy alkaloids include compounds like castanospermine and swainsonine.

The primary alkaloids within the pumiliotoxin category are pumiliotoxin A and pumiliotoxin B. Other representatives include gephyrotoxin 223 AB and gephyrotoxin.

Representatives of this alkaloid group include tylophorine, tylocrebrine and tylophorinidine.

Representatives of this group include Elaeocanine A, Elaeocarpine and Elaeocarpidine.

The main alkaloid in this category is securinine. Others are securinol A and norsecurinine.

Most of the Tylophora alkaloids belong to the phenanthroindolizidine alkaloid family, including tylophorine, septicin, and hispidine.