{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T05:04:46Z","timestamp":1789362286861,"version":"build-2803163510"},"reference-count":23,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T00:00:00Z","timestamp":1789344000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Pharmacol."],"abstract":"<jats:p>Opioid withdrawal remains a significant barrier to cessation, particularly in treatment-experienced populations who have made repeated unsuccessful attempts using established pharmacotherapies. SR-17018 is a \u03bc-opioid receptor agonist with preclinical evidence of reduced \u03b2-arrestin 2 recruitment and altered receptor regulatory dynamics relative to conventional opioids. Whether these properties translate into clinically meaningful differences in humans remains unknown. This report presents a descriptive analysis of a self-reported observational registry (N = 55) characterizing SR-17018 exposure patterns, perceived outcomes, and adverse effects. Most participants (69.1%) reported three or more prior detoxification attempts, characterizing the cohort as treatment-experienced and refractory. During SR-17018 exposure, 54.5% of participants reported full cessation of opioid use and 32.7% reported meaningful reduction in use; smaller proportions reported no change (5.5%) or relapse (7.3%). Collectively, 87.3% reported improvement. These outcomes are self-reported and were not independently verified. Most participants reported dosing SR-17018 three or more times daily (76.4%), with perceived effects lasting approximately 4\u20138\u00a0h per dose (54.5%). Participants reported a mean withdrawal relief score of 8.20\/10 (SD and distribution reported in Results), with 90.9% rating relief at seven or higher. Adverse effects were predominantly mild to moderate and included anxiety, sweating, sedation, insomnia, gastrointestinal symptoms, and subjective breathing-related concerns in a minority of respondents (7.3%); the nature of these breathing reports could not be medically verified. Because the recruitment channel selects against participants who discontinued for adverse effects or inefficacy, and because approximately half the cohort reported concurrent use of other substances, these tolerability figures\u2014including the low discontinuation rate (1.8%) \u2014 are biased toward a favorable safety impression and cannot be read as evidence that SR-17018 is well tolerated. No objective safety monitoring was performed. These findings provide preliminary descriptive data characterizing real-world SR-17018 exposure in a treatment-experienced population. The uncontrolled, self-reported, cross-sectional design precludes any conclusion regarding efficacy or safety, and the sample is likely biased toward favorable experiences. The principal value of these data is to motivate and prioritize controlled human investigation: prospective, objectively monitored studies are required before any clinical inference about SR-17018 can be drawn.<\/jats:p>","DOI":"10.3389\/fphar.2026.1899247","type":"journal-article","created":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T04:36:02Z","timestamp":1789360562000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Observational characterization of self-reported SR-17018 exposure and outcomes in individuals with prior opioid use histories"],"prefix":"10.3389","volume":"17","author":[{"given":"Mark P.","family":"Picard","sequence":"first","affiliation":[{"name":"Independent Researcher","place":["Denver, CO, United States"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,9,14]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"896","DOI":"10.1080\/13880209.2025.2590311","article-title":"From kratom to 7-hydroxymitragynine: evolution of a natural remedy into a public-health threat","volume":"63","author":"Alsbrook","year":"2025","journal-title":"Pharm. 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