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Citizens Petition 2

A public filing requesting FDA review of research questions concerning whether opioid exposure may be associated with measurable biological markers.

People. Science. Answers.
Filed with
Filed with: U.S. Food and Drug
Administration
Date filed
Date filed: January 14, 2026
Docket number
Docket number: FDA-2026-P-0142
Petition status
Status: Pending

Petition Summary

What the petition asks
Requests that the FDA review whether there is a reasonable basis to investigate whether opioid exposure may be associated with measurable biological markers, including genetic or epigenetic changes.
Why it was filed
Fewer long-term biological effects of opioid exposure are well understood. This petition asks the FDA to consider whether additional research and guidance are warranted.
What it relies on
Cites published scientific literature, government reports, and relevant archival material, and summarizes findings that suggest potential biological effects.
FDA response to date
The FDA has acknowledged receipt of the petition on January 28, 2026. The petition is currently under review.
Petition document

Citizens Petition 2

PDF · 42 pages · 3.8 MB

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What this petition says in plain language

1

Poses a research question
before the FDA

Formally requests FDA review of whether opioid exposure may be associated with measurable biological markers.

2

Summarizes why the question merits review

Explains the public health importance and the need for further investigation based on existing evidence.

3

Draws on published and archival sources

Cites peer-reviewed research, government reports, and other relevant materials to support the request.

4

Asks for review and consideration

Requests that the FDA consider the evidence and determine whether additional research or guidance are appropriate.

PETITION DOCUMENT

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RESEARCH & SOURCES

Evidence cited in this petition

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✓ ESTABLISHED RESEARCH 01

Sun, E. C. et al. (2017).

Association of prescription opioid use with adverse health outcomes: a systematic review. AMA, 118(9), 1564–1571.

Sep 12, 2017
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? SGR QUESTION 02

Zhou, Z. et al. (2020).

Opioid exposure and epigenetic modifications: a systematic review. Neuroscience & Biobehavioral Reviews, 118, 182–197.

Mar 1, 2020
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✓ UNDER INVESTIGATION 03

Takahashi, M. et al. (2019).

DNA methylation changes in individuals with opioid use disorder, Translational Psychiatry, 9, 129.

May 21, 2019
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✓ ESTABLISHED RESEARCH 04

U.S. Food and Drug Administration. (2022).

Opioids: Regulatory history and future considerations. FDA Drug Safety Communication.

Jan 12, 2022
View source →
? SGR QUESTION 05

Volkow, N. D. (2021).

The lasting biological effects of opioids: A call for further research. Nature Medicine, 27, 523–525.

Apr 8, 2021
View source →
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REGULATORY PROCESS

Regulatory Timeline

✓

Research question identified

Mar 10, 2025

✓

Petition drafted

Nov 3, 2025

✓

Petition filed

Jan 14, 2026

✓

Acknowledgement received

Jan 28, 2026

Review pending

Jan 28, 2026 – Present

Public updates

Ongoing

NEXT STEPS

What happens next

The FDA citizen petition process

The FDA reviews citizen petitions to determine whether the request is actionable and whether further study or guidance is appropriate.

Expected timeframes

The FDA does not have a fixed timeline for responding to citizen petitions. Timing may vary, and in some cases a response timeframe may be unknown.

How updates will be published

Updates will be posted on our Updates page, if the petition is acknowledged. Any relevant information becomes available.

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