Myrcene Terpene Effects
Myrcene is a monoterpene with the formula C10H16. It is the main terpene in hops and it appears in lemongrass, thyme, basil, bay leaf, and mango. In rodent studies, myrcene causes sedation, raises pain thresholds, and lowers markers of inflammation. Controlled human trials that dose myrcene on its own are rare. Most claims about myrcene in cannabis come from lab work, from terpene profiles printed on labels, and from anecdote.
What myrcene is
- CAS number 123-35-3
- Boiling point about 167 C (332 F)
- Hops essential oil holds 30 to 50 percent myrcene in many samples
- Listed as a permitted flavoring substance in US food under 21 CFR 172.515
The isomer alpha-myrcene has a different double bond position. Cannabis labs report beta-myrcene, the form used in most research.
Myrcene Benefits and Side Effects: A Practical Guide
Sedation
A 2002 mouse study found that myrcene extended sleep time caused by pentobarbital. The effect rose with dose. This is the source of the term couch-lock tied to myrcene. Mice are not people, and the study used isolated myrcene, not inhaled flower. No human trial has measured sedation after a set myrcene dose.
The 0.5 percent rule
Retail guides often state that cannabis with more than 0.5 percent myrcene causes heavy sedation. No peer-reviewed human study sets that cutoff. Lab methods differ, so a 0.5 percent reading from one lab may not match another. Treat the number as folklore, not a threshold.
What Does Myrcene Do? Terpene Effects and CBD Reality
Pain and inflammation
Mouse models show myrcene reduces response to pain. Naloxone blocks part of that effect, which points to opioid receptor activity. Cell studies show lower release of inflammatory cytokines. These results do not prove that a myrcene dose in a person lowers pain.
Interactions and safety
In lab dishes, myrcene slows some cytochrome P450 enzymes. Those enzymes break down many drugs. A slowdown could raise drug levels in the body. No human study has measured this. Myrcene is approved as a food flavoring, so intake from food is not a concern at normal amounts.
Reading a terpene label
A terpene panel from a batch certificate of analysis lists myrcene in milligrams per gram or as a percent. Ask for the batch number and the test date. Terpene content shifts with harvest, storage, and heat. A jar left in a warm car will lose myrcene before you open it.