Vitamin C / Ascorbic Acid
Unflavored Vitamin C can be ordered from Safety Works, Total Access Group and other retailers. Vitamin C amounts and prices generally vary- what you can count on is having to hygienically package it yourself (2×2 amfAR baggies work well). Total Access Group sells 300 gram bags for $20 and 2 lb bags for $34.96, Safety Works sells 226 grams for $26.29 although you can find the same product (Kal C-Crystals) online much cheaper.
Information taken directly from “Guide to Developing and Managing Syringe Access Programs” by Harm Reduction Coalition, 2010
Powdered Citric or Ascorbic Acid is used for helping to dissolve crack and other solid drugs. This may actually be a required item, if participants are injecting crack and/or certain forms of tar heroin or solid drugs.
In order to inject crack and other solid drugs, the first need to be broken down and dissolved. IDUs will commonly use vinegar or lemon juice in this process which can cause dangerous bacterial infections and abscesses. Reducing abscesses and other skin infections also has implications for transmission of HCV and other blood-borne infections because of the subsequent presence of open wounds and potential for blood transmission.