PROJECT SUMMARY PRevention Of Methamphetamine Use among Postpartum Women Trial (PROMPT) is a randomized controlled trial of postpartum individuals with methamphetamine use disorder to micronized progesterone or placebo. This research study is pursuing two specific aims: (1) To assess feasibility, safety, and preliminary efficacy of micronized progesterone to decrease return to methamphetamine use among postpartum individuals with methamphetamine use disorder; (2) To evaluate the association between salivary allopregnanolone levels and methamphetamine craving in control and treatment groups. For Aim 1, we are randomizing 40 postpartum individuals with methamphetamine use disorder within 12 weeks of the end of pregnancy who have achieved abstinence for four weeks to micronized progesterone or placebo and will assess methamphetamine use over 12 weeks. We are tracking enrollment and retention of postpartum individuals, safety of this intervention and establishing preliminary efficacy of progesterone to reduce return to methamphetamine use. For Aim 2, we are testing the hypothesis that increased allopregnanolone levels, an active metabolite of micronized progesterone, are correlated with reduced methamphetamine cravings among postpartum individuals. Our long-term goal is to advance the understanding of how postpartum individual’s unique physiology impacts methamphetamine use disorder and to apply this knowledge to developing novel interventions aimed at reducing methamphetamine use in this population. This project is innovative as it addresses a significant health issue facing this vulnerable population with a novel intervention. The proposed research is significant because of its potential to improve public health by decreasing methamphetamine use among postpartum women and to advance scientific knowledge by investigating the association between allopregnanolone and methamphetamine cravings. The rationale for this supplement to the parent grant is to address the Principal Investigator’s qualifying life event which delayed the start-up of PROMPT study. The supplement’s funding will be used to fund research coordinator time to continue recruitment, enrollment and retention of participants in the PROMPT study.