Prescription medications
This method has a lot more nuance to it, as certain prescriptions have a high likelihood of lethality when taken in the right doses, while others have next to 0 chance. Generally, most prescriptions have a low chance of killing you. Psychiatric medications are the most discussed on this forum, and are also on the lower end of having any shot at killing you. Antidepressants vary in chance of killing you, though even the most toxic (tricyclics) have only about a 14% chance, not a very good statistic. At worst, certain antidepressants have only a 0.5% chance. Other medications, such as those taken for chronic conditions, vary wildly, however the list of those with a high chance of killing you is significantly shorter than the ones with little or moderate chance. Obviously it would be far too tedious to go and list off all of them.