Diabetes Drugs Linked to Suicidal Ideation, Potential Birth Control Interference, Australian Authorities Warn
CANBERRA - Australian regulators have issued new warnings regarding glucagon-like peptide-1 (GLP-1) drugs – initially developed for diabetes treatment but increasingly popular for weight loss – citing potential links to suicidal thoughts and behavior, and also possible interference with teh effectiveness of oral contraceptives. The Therapeutic Goods Governance (TGA) alert follows emerging reports and conflicting studies examining the safety profile of these medications.
GLP-1 drugs function by lowering blood sugar and suppressing appetite. Currently approved in Australia are Mounjaro (tirzepatide), Ozempic (semaglutide), Wegovy (semaglutide), Saxenda (liraglutide), and Trulicity (dulaglutide). While common side effects like nausea, vomiting, diarrhea, indigestion, and abdominal pain are typically mild and subside over time, the TGA’s recent announcement raises more serious concerns.
According to a report by The Autonomous, 20 cases of suicidal ideation perhaps associated with GLP-1 use where reported in Australia within the 12-month period ending November 2025. A 2024 study indicated a potential 106% increase in the risk of suicidal behavior linked to these medications, and analysis of World Health Association data also suggested a connection between semaglutide and suicidal thoughts.However, a separate, large 2024 study involving 1.8 million patients found no increased risk of new-onset suicidal ideation, and even suggested a potentially lower risk. The TGA acknowledges the conflicting scientific findings and states the exact level of risk remains unclear.
Beyond mental health concerns, emerging evidence suggests GLP-1 drugs may impact the absorption of hormones from oral contraceptives. Oral birth control pills rely on consistent hormone levels to prevent ovulation and thicken cervical mucus. Reduced hormone absorption could compromise their effectiveness. Research indicates tirzepatide (Mounjaro) may considerably reduce hormone absorption. While a 2015 study found no such effect with semaglutide, a 2025 study revealed potential decreases in birth control pill hormone levels with both tirzepatide and oral semaglutide.
Importantly, the TGA notes that hormone-releasing birth control methods like intrauterine devices (IUDs) and implants are not affected, as they do not depend on gastrointestinal hormone absorption.
The TGA advises individuals experiencing new or worsening depression, suicidal thoughts, or mood changes while taking GLP-1 drugs to immediately consult their doctor. For women using oral contraceptives alongside tirzepatide, the TGA recommends switching to a non-oral contraceptive method or utilizing an additional barrier method for the first four weeks of treatment and with each dose increase.