There are currently more than 200 shortages of medications, including some forms of menopause hormone therapy, ADHD medication and birth control. 

It's not always clear why some medications are in short supply, but sometimes the shortage can be traced all the way to a farm in China. 

Also, why US President Donald Trump wants to target Australia's Pharmaceutical Benefits Scheme (PBS). 

References

• Medicine shortage reports database - TGA
• Understanding the impact of medicine shortages in Australia Discovery report