Refers to a substance or thing that stimulates or excites the body, mind, or a system. Can be used for both positive stimulation and irritation.
Caffeine is one of the typical stimulants.
This cosmetic does not contain irritants, so it can be used even on sensitive skin.
刺激 is the abstract noun for 'stimulus' or 'stimulation', while 刺激物 specifically refers to a concrete substance or thing that causes stimulation.
Standard kanji spelling.
Rare variant using 戟 instead of 激.
Compound of 刺激 (stimulus) + 物 (thing). The kanji 刺戟物 is a rare variant using 戟 for the second character.