Drug users have being warned not buy a "legal high" sold as bath salts on the internet after several people needed hospital treatment.
NHS Bournemouth and Poole said it had seen people who had taken the drug, known as ivory wave, ivory coast or purple wave, in the last few days.
The drug's side effects include rapid heartbeat and rising blood pressure.
A spokesman said "there is little clarity over its exact ingredients" and agencies are trying to raise awareness.
Dr Adrian Dawson, director of public health for Bournemouth and Poole, said: "This drug has caused adverse reactions in people locally and we want to make sure that people keep themselves safe.
"Our advice is not to take any drug, especially those over the internet, as no-one can be sure what they contain."
The drug also increases anxiety, causes prolonged panic attacks, constricts blood vessels, suppresses hunger and causes insomnia and sweating.