HSE's safety advice for taking ecstasy
The HSE has issued drug safety advice for festival goers including only taking a "quarter of a pill" at first to test potency.
The advice from the health service comes after two young people died in the UK this week.
The 10-point tip on taking ecstasy, or MDMA, at a festival also warns not to mix drugs with alcohol.
Dr Eamon Keenan, HSE clinical lead for Addiction Services, said the decision to issue the advice was made following a number of tragic incidents in the UK in recent weeks.
Dr Keenan said it was a harm reduction message and there must be a realisation that people take drugs.
He added it would be safer if people would not take illegal drugs, but practical advice could help those who do at festivals.
"We are aware that there have been deaths and hospitalisations at festivals in the UK recently associated with the use of illicit drugs. We are also aware that there are high dose batches of ecstasy or MDMA in circulation," said Dr Keenan.
"The advice says it is always safer not to use ecstasy/MDMA, but if you do, test-dose a new batch - begin with a low dose, quarter pill."
Users should wait at least two hours before using any more, and are warned that some pills are cut with other substances.
Festival-goers are told to stay with trusted friends, keep hydrated and eat properly.