The updated World Anti-Doping Agency (WADA) Prohibited List for 2017 has come into force today amid unprecedented warnings.
Many International Federations and National Olympic Committee have posted reminders of how the list is applicable from today in a bid to avoid a repeat of the mass failures which followed the addition of meldonium to the 2016 list.
Swimmer Yulia Efimova and tennis superstar Maria Sharapova were among dozens of top Russian and Eastern European stars to fail for the heart medication, which it is claimed boosts endurance.
Many, including Sharapova, claimed they were not aware that the product had been outlawed.
Many of these athletes have now returned to competition after WADA conceded that "more research was required" to ascertain how long the substance remains in the human body.
Meldonium remains on the 2017 list of banned substances.
New additions include lisdexamfetamine, a drug used for treating attention deficit hyperactivity disorder and eating disorders, and the narcotic opioid analgesic nicomorphine.
Arimistane, also described as androsta-3,5-diene-7,17-dione, is thought to be the substance most likely to lead to mass failures after being added to the list of banned hormone and metabolic modulator.
The substance is freely available in over-the-counter supplements in many parts of the world and is used to lower estrogen levels, which can also contribute to the stimulation of muscle growth.
Specific warnings about the changes have been placed on the website of the All-Russian Swimming Federation and other national governing bodies.
The new list, which has been published online since September, also makes clear that salbutomol, salmertor and formoterol are the only permitted "beta-2agonists" which can be used to treat asthma.
Clearer criteria have been introduced to define how these products can be used legally.
Inhaled salbutamol is permitted at a maximum level of 1,600 micrograms over 24 hours, or 800 micrograms every 12 hours.
Inhaled formoterol can have a maximum delivered dose of 54 micrograms over 24 hours, while a maximum of 200 micrograms of inhaled salmeterol is permitted over 24 hours.
Click Here to see the Full World Anti-Doping Agency (WADA) Prohibited List for 2017