IMPORTANCE: There are few effective pharmacotherapies for treating eating disorders (EDs). High rates of substance use among individuals with EDs suggest potential self-medication of symptoms. OBJECTIVE: To explore the experiences of individuals with EDs regarding use of prescribed and nonprescribed drugs. DESIGN, SETTING, AND PARTICIPANTS: This survey study assessed responses to the Medications and Other Drugs for Eating Disorders (MED-FED) survey, which was advertised internationally using social media, online forums, and clinical services and recruited adults who self-reported an ED or disordered eating from November 10, 2022, to May 31, 2023. The online survey queried about recent prescribed and nonprescribed drug use as well as the perceived benefits and harms of each substance. EXPOSURES: EDs or disordered eating and co-occurring mental health conditions. Substances evaluated included caffeine, alcohol, nicotine, cannabis, prescription psychotropics, psychedelics, ketamine, 3,4-methylenedioxymethamphetamine (or ecstasy), stimulants, opioids, and other drugs. MAIN OUTCOMES AND MEASURES: Respondents described drug use over the past 12 months. For each drug used, they rated their agreement or disagreement on a 5-point Likert scale (-2, strongly disagree; -1, disagree; 0, neutral; 1, agree; or 2, strongly agree) with the following 3 statements: (1) this medication/drug makes my eating disorder symptoms better; (2) this medication/drug has overall benefits for my mental health; and (3) this medication/drug has unpleasant side effects. RESULTS: There were 7648 participants recruited, of whom 6612 completed the demographic portion, and 5123 completed the entire survey. Among the 6612 respondents (mean [SD] age, 24.3 [7.7] years), the sample was predominantly female (6217 [94.0%]), and most resided in Australia (1981 [30.0%]), the UK (1409 [21.3%]), or the US (1195 [18.0%]). Diagnosed EDs included 2696 (40.8%) individuals with anorexia nervosa, 1258 (19.0%) with bulimia nervosa, 757 (11.4%) with binge-eating disorder, and 589 (8.9%) with avoidant/restrictive food intake disorder. Many respondents (2493 [37.7%]) were undiagnosed. Psychiatric comorbidities were highly prevalent; depression was reported by 4333 respondents (65.5%). Cannabis and psychedelics were highest-rated for improving ED symptoms. Prescription antidepressants were rated highly for overall mental health but not for ED symptoms, with the exception of fluoxetine for bulimia nervosa and lisdexamfetamine for binge-eating disorder. Alcohol, nicotine, and tobacco were rated as the most harmful drugs. CONCLUSIONS AND RELEVANCE: The findings of this survey study of prescription and nonprescription drug use suggest that cannabis and psychedelics were perceived by survey respondents as efficacious in alleviating their ED symptoms, which supports further research in this area. Prescription psychotropics were perceived as being relatively ineffective for ED symptoms but beneficial to general mental health.