No. Ayahuasca itself is not named in Irish law, but its main active compound, DMT (N,N-dimethyltryptamine), is listed in Schedule 1 of the
Misuse of Drugs (Designation) Order 2017, made under section 13 of the Misuse of Drugs Act 1977. For the substances on that list, manufacture, production, sale, supply and possession are unlawful except for research or forensic analysis. An Garda Síochána puts it plainly: "it is an offence to cultivate, import, export, produce, supply and possess N, N-Dimethyltryptamine (DMT) except in accordance with a Ministerial Licence". No such licence exists for ceremonies.