Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate (abbreviated BTMPS) is a hindered amine light stabilizer used to protect plastics and coatings such as paint from oxidation caused by sunlight weathering. Like most compounds of this class, the activated form is an aminoxyl radical.
It is produced by the diesterification of sebacic acid (decanedioic acid) with 4-hydroxy-TEMPO.
In 2024, it was detected as an adulterant in illicitly sold fentanyl in the United States. It is capable of inhibiting nicotinic acetylcholine receptors. Additionally, it is a potent blocker of L-type calcium channels. It is also able to induce dose-dependent hemodynamic alterations. Similar to early calcium channel blockers, it can precipitate adrenergic release.