The Thai Public Health Ministry has issued a warning after images of a Thai man undergoing a whitening treatment on his penis went viral, according to a report published by the BBC.

The ministry has warned of the possible side effects such a treatment could provoke, such as swelling, scarring and even loss of sexual function and fertility.

“Penis laser whitening is not necessary, wastes money and may give more negative effects than positive ones,” said the ministry’s Thongchai Keeratihuttayakorn in a statement.

A Facebook post written by the Lelux Hospital, which offers both vaginal and penal laser whitening, was shared more than 19,000 times in the space of two days. The clinic is said to treat up to 30 patients a month.