Use it right before they age up for maximum value. The potion only gives one drink, but will reset the Sim back to the beginning of their current age group. The Potion of Youth Reward is the easiest means of keeping a Sim youthful without cheating. Setting the Life Span to long will make children and teens take quite some time to age up, but you'll have loads of time to accumulate satisfaction for the following reward. You can select whether all Sims age, or only those in your household, or disable aging entirely. Know that there are aging settings in The Sims 4's gameplay options menu. Let's explore some of the means of life-extension in the game, and what we can do to make that a regular part of the Sim's life. Some involve cheats, while others do not. There are a few ways to make your Sim live forever in The Sims 4. Potions of Youth do the same, costing 1500 Satisfaction. The Sims 4 Age Extension and Immortality Drinking the Essence of Life from a Cow Plant will reset your Sim back to day 1 of their current life stage.