Powder to the People

 is an unmarked quest in Fallout: New Vegas.

Walkthrough
When talking to Siri, a female slave working for Caesar's Legion at The Fort, she will tell you about her tough life as well as her healing powder.

With a good Legion reputation, you can get it from her. Even better, with a 20 Survival skill, you can tell her how to improve the recipe.

The player can then return to her, once a day, to get some free healing powder. If she is given the better recipe, it will have greater potency.