In the early days of the ban of meldonium, a supplement/heart medication popular among Russian athletes that led to the second positive test for Yulia Efimova and a first positive test for Grigory Tarasevich, among many others, very few suspensions were given out.
That came as a result of athletes successfully arguing that they weren’t given enough warning that the substance would be outlawed, and claiming (in what seems to be an accepted statement) that at the time, there wasn’t enough viable research on how long the substance would remain in a person’s system after it was outlawed. The ban was announced about 6 weeks prior to it taking effect on January 1, 2016.
Early tests in that period were met with a no-fault finding, and were given little-to-no punishment. The exception is Russian tennis superstar Maria Sharapova, who unlike most that tested positive for it admitted to having taken it after the ban (though she said that she wasn’t aware that it had been outlawed).
While no official announcement was made by WADA, it seems as though Meldonium has officially become a substance that athletes can become banned for. The best indication of this is a 4-year suspension handed to Zambian distance runner Jordan Chipangama earlier this month by the United States Anti-Doping Association, which is more transparent in publishing its testing history and findings than almost any organization on earth.
The result of two samples collected in June and August of 2017, respectively, were the first to receive the maximum 4-year suspension from USADA. The last case adjudicated by the organization for meldonium was Ivan Tutukin, a triathlete who tested positive as late as May 23rd, 2016, and he was given a no-fault violation. At the time, he said that he stopped using the medication in October of 2015, 7 months before his test, after more than a decade of using it.