The plant Lycopodium clavatum, known as club moss, is the Lycopodiaceae family and used to treat range of ailments in European and Asian countries. Quinolizidine alkaloids are found in crude extracts from several areas of the herb. Several researchers has reported on the therapeutic potential of alkaloids produced from this plant, but there are few publications on adverse effects of alkaloids from this plant. In such a circumstance, a greater understanding of its ameliorative effect as well as harmful effects is required. This review outlines scientific results and identifies areas in which more study is required.