As restrictions against marijuana are loosening in many parts of the country, the growing interest in cannabis has opened the door to a lesser-known danger: synthetic pot.

Synthetic pot is a product created by spraying plants with substances that act like the active chemicals in marijuana. The problem is, these substances aren’t exactly safe.

A Centers for Disease Control and Prevention report states that calls to U.S. poison control centers concerning ill effects from synthetic pot have more than tripled since January 2014. As of April 2015, fifteen-hundred calls had been made to poison control centers concerning synthetic pot.

The most common symptoms callers reported included rapid heartbeat, drowsiness, confusion, vomiting and agitation. Most of the synthetic pot users were males, with a median age of 26, the researchers noted. Guys who called in were more likely to be experiencing a serious reaction than a minor one. Also, people age 30 and older were at higher risk of a severe problem than people aged 10-19.

Some cases ended with a death. At the time of the report, 2015 already had seen three times as many deaths from synthetic pot … 15. This is the same number recorded for all of 2014.

This number includes only cases where a poison control center was contacted. Thus, the actual number of deaths and overall cases may be higher.

Officials are finding it tough to crack down on synthetic pot sales, so consumers need to watch out for themselves and avoid the stuff altogether.

Synthetic pot may be sold as an herbal product, under names such as black mamba, spice, K2 and others, the report stated.

What these catchy names don’t convey is the danger synthetic marijuana poses. Experimentation and temporary fun are not worth the risk to your health.