The HSE has issued a warning in relation to what it describes as a "very dangerous" high strength of MDMA in circulation this festive season.
Professor Eamon Keenan, National Clinical Lead on addiction services said that over the summer a high strength of MDMA was identified.
He said it is three times the adult average dose and has significant health risks.
Prof Keenan said that this particular strength of MDMA is still available, and that people taking it need to be aware that one pill is not equal to one dose.
"This higher strength MDMA circulating has got significant health risks."
He said that although it is always safer not to take drugs, that if people do, they need to look out for themselves and their friends and if they see someone suffering adverse consequences, they should seek help immediately.
He added that the HSE is there to support people and people should not be afraid to talk, as medics are not there to judge when it comes to taking drugs.
Prof Keenan also said that he understood why people may be reluctant to get help, but medics are there to help and the adivse is not to sit on it if someone starts to feel unwell and deteriorate rapidly.
In terms of symptoms of a potential overdose or side affect, he said that people might suffer a seizure after taking the drugs, high temperatures or cardiac complications, cardiac arrest, muscle twitches or overheating.
He added that there are many parties and social occasions over the festive season and in those circumstances health services and emergency services will see an upsurge in attendances.
