The warning comes following the discovery by the PSNI of a number of empty legal high packets in a number of different areas in Strabane and Sion Mills.
This new legal high is known as "Magic Dragon".
It is sold as a chemical infused potpourri and the packets are covered with warnings, similar to a bottle of bleach, regarding consumption, inhalation, eyes and pregnancy.
Police say it appears that the packets were being opened and then divided into smaller polythene bags.
Which they say indicates a form of low level supply were profit is being made by dividing the substances up and selling them on.
Parents are being urged to look out for these substances and related items which are readily available and legal at present.