Samarium-153 has a physical half-life of 46 hours. It has beta emissions of 640 (30%), 710 (50%), and 810 keV (20%). It also has a gamma emission of 103 keV (28% abundance) which is adequate for scintigraphic scanning and allows specific localization of metastases which have accumulated the tracer. Following administration the agent is rapidly cleared from the blood (usually within one hour).

Between 45-95% of dose localizes to the skeleton (complexes to phosphate for bone targeting) with less than 2% in non-osseous tissues, mostly the liver. Excretion is primarily renal.

In the palliation of painful bone mets 69% of patients treated with Samarium-153 experienced symptomatic relief of bone pain with a mean duration of benefit of 4 months.

Complications of Samarium-153 treatment include a mild transient myelosupression.