active ingredient

active ingredient (plural active ingredients)

1. (especially pharmacology) The specific compound in a natural or man-made mixture that is responsible for the mixture's activity.

   Antonym: inactive ingredient

   Hypernym: ingredient

   Hyponyms: API, active pharmaceutical ingredient

2. (figurative) The essence of something, or a sine qua non that it requires.
   • 2025 December 9, Adam Mastroianni, “The drug that taught me how much I should suffer; or: grindset and bedrot”, in Experimental History (Substack newsletter)‎^[1]:

     I think many humans never learn how to do this, either. They assume that our existence is nothing more than an endless lurching in the direction of the things you want, and never actually getting them. Life is hard and then you die; stick a needle in your eye! There are people with the opposite problem, of course: people who refuse to take on any amount of discomfort in pursuit of their goals, people who try not to have any goals in the first place, for they only bring affliction. It’s a different strategy, but the same mistake. These two opposing approaches to life—call them grindset and bedrot—both assume that the ratio between pain and gain is fixed. The grindset gang simply accepts every deal they’re offered, while the bedrot brigade turns every deal down. Neither camp understands that when you get your Suffering Ratio right, it doesn’t feel like suffering at all. The active ingredient in suffering is pointlessness; when it has a purpose, it loses its potency.