Terpenes
Limonene
A terpene associated with citrus aromas.
Say it: LIM-o-neen
Last reviewed: 2026-09-14
The basics
Limonene occurs in different molecular forms. The d-limonene used in the human study below is one specific form; a product label may simply say “limonene.”
What the evidence means
A controlled study of 20 adults compared vaporized THC, d-limonene, their combinations and placebo. Some combinations reduced reported THC-related anxiety. This small study does not establish that a limonene-rich retail product prevents anxiety or improves mood.
A useful question
Does the batch report measure limonene, and how much? A citrus description is not a treatment claim.
Sources and further reading
Use the sources to check the scope of each claim. A chemical measurement, a laboratory experiment and a study in people answer different questions.