The purpose of the study is to evaluate the safety, efficacy, and pharmacokinetics of four single, increasing doses of CS-1103, given by intravenous (IV) infusion in otherwise healthy, non-treatment seeking participants with methamphetamine use disorder in the presence of a clinically relevant dose of methamphetamine HCl (30 mg IV).

Major Inclusion Criteria:

1. Healthy participants aged 18 to 55 years, inclusive;
2. Meets DSM-5 criteria for methamphetamine use disorder;
3. Not seeking treatment for methamphetamine use disorder;
4. Primary route of methamphetamine self-administration must be intravenous or smoking;
5. Able to abstain from methamphetamine without experiencing severe withdrawal;
6. A body mass index between 18 to 30 kg/m2, inclusive and a minimum body weight of 56 kg;
7. Females must not be lactating and must have a negative pregnancy test during screening and admission.

Major Exclusion Criteria:

1. Estimated glomerular filtration rate <60 mL/min/1.73 m2;
2. History of cardiovascular disease;
3. Current moderate to severe use disorder for alcohol, cannabis, cocaine, opioids, or benzodiazepines;
4. History of any clinically important disease or disorder which, in the opinion of the Investigator, may interfere with safe study participation.