The base of most medications are plants which you would never eat. Just like you would not eat a hog pancreas which is where insulin used to be produced from in humans. Most of those plants in which medications come from would kill you if you ate them, so there are side effects. But in noting that, every thing you eat has side effects. Eat too much sugar and you will swell up like a balloon. Eat oranges the side effect is you do not get rickets.
People vary in what they can ingest. Some people drink beer with no problems and others get stomach problems. Not every long or short chain reacts the same with your amino acid structure, so not every side effect effects every person in medications.
There is though a reality in medications make huge amounts of money, which is why they are prescribed. Most people do not need all the meds they pop and rattle around with every day. My dad had high blood pressure, because he was fat. That pill killed his B cells in his pancreas so he developed diabetes, which in time as he refused to lay off sugar, produced a silent heart attack which killed him. So fried chicken produced in quantity high blood pressure and a pill killed him, which was coming anyway and the pill just delayed the death. In the meantime, his prolonged life manifested another exotic lung disease which almost killed him, but was cured with steroids and blood thinners, whose side effects were aggressiveness and severe bruising.
My mother was the exact opposite in she took no meds, had a weak heart, fluid built up, it was dealt with, but eventually her heart quit. If she would have taken diuretics, she would have lingered, had amputations from the fluid in her legs and died slowing in a nursing home. That is a horrid side effect not on the bottle in a prolonged life past it's time. Nature does inform people when it is time to check the door, as she broke her hip 10 years before her death, was pinned, put on a calcium bone enhancer for year, and it gave her about 8 more years of watching television.
Everything has causes and effects. Some things I would not choose, like meds that turn people into zombies so they do not react when you say hello to them, but they are still alive. One of the leading causes of death in the United States are prescription medications each year. Pharm is in it to make money and if they can save you from one condition and kill you with another, as long as it makes money, is all that they are interested in.