More than 700,000 units of illegal medicines have been intercepted in the first six months of the year - up from just over 550,000 in the same period last year.
The Health Products Regulatory Authority said 'sedative' medicines and 'erectile dysfunction' medicines made up a sizable number of the seizures.
HPRA Director of Compliance Gráinne Power has warned prescription medicines being purchased online from unauthorised sources pose a serious health risk to anyone who takes them.
“They have a potent impact on your body and they will damage your liver, damage your kidneys, damage your heart,” she said.
“Not to mention mental health issues that they create.
“So, not medicines to be messed with at all and certainly not medicines to get from someone who is not medically trained.”
Anabolic steroids - which are used sometimes misused in order to grow muscle mass - made up 23% of the seizures.
“As an organisation together with Revenue, we have seized over one million units of anabolic steroids since 2018,” she said.
“So, these are potent medicines with a very specialist use in a legitimate medical practice but they are around the country in the community being sourced online and they’re being used for body image.”
Misuse of anabolic steroids can lead to a heart attack or stroke, as well as liver or kidney problems.
Main image: An illustration showing medical pills. Picture by: FrankHoermann/SVEN SIMON/DPA/PA Images