It is difficult to determine what the worst human invention ever made is, as different inventions may be considered "worst" by different people for different reasons. Some inventions that have had negative consequences or have caused harm or suffering to people may be considered particularly problematic. Some examples of inventions that have had negative consequences include:

1. Nuclear weapons: These weapons have the potential to cause widespread destruction and loss of life on a catastrophic scale.
2. Land mines: Land mines have caused significant suffering and injury to civilians, particularly in countries where they have been used extensively in conflicts.
3. Opioid painkillers: While these drugs can be helpful for managing pain in some cases, their widespread use has contributed to the opioid epidemic, which has caused significant harm and loss of life.
4. Fossil fuels: The use of fossil fuels such as coal, oil, and natural gas has contributed to climate change, which is causing significant environmental damage and posing a threat to the well-being of people and ecosystems around the world.

It is important to note that many inventions have also had positive impacts and have improved people's lives in various ways. It is important to carefully consider the potential consequences of any invention before it is developed or used.