Missouri House members have given first-round approval to legislation taking aim at synthetic drugs.
The bill would add several specific substances to what is considered synthetic marijuana.
It was endorsed by a voice vote Tuesday and needs a second vote before moving to the Senate.
In recent years, Missouri has tried to keep pace with evolving synthetic drugs and twice has approved legislation targeting them. Sponsoring House member Shawn Rhoads says the current bill is needed to stay ahead in the effort.
Lawmakers in 2010 barred spice cannabinoids sold as incense known as K2. A year later, the definition of marijuana in state drug laws was expanded to cover synthetics. The 2011 measure also barred substances marketed as incense or "bath salts" that mimic the effects of cocaine and marijuana.