How the opioid receptor sends different signals that affect pain relief and side effects

The structural basis for pathway-selective signaling by the µ opioid receptor

NIH-funded research Stanford University · NIH-11264878

Researchers are mapping how opioid receptors trigger different signals to help develop safer pain medicines for people with acute or chronic pain.

Quick facts

Grant typeR01 grant
Study typeNIH-funded research
Funding institutionStanford University NIH-funded
Lab location1 site (Stanford, United States)
Project IDNIH-11264878 on NIH RePORTER

What this research studies

From my perspective, the team is studying the µ-opioid receptor—the molecule that opioid drugs like morphine and fentanyl act on—to learn which internal signals lead to pain relief and which cause harms like addiction or breathing problems. They are examining how different drugs preferentially activate specific G protein subtypes and arrestins, and have already found compounds that favor pain-relief pathways. Using detailed structural approaches, they plan to see how those drugs bind and change receptor shape. That knowledge will guide the design of new opioid drugs that aim to keep pain relief while reducing dangerous side effects.

Who could benefit from this research

Good fit: People with acute or chronic pain who use or may need opioid pain medicines would be the primary beneficiaries and could be candidates for future clinical trials.

Not a fit: People whose pain does not respond to opioids, or those not exposed to opioid treatments, may not receive direct benefit from this research.

Why it matters

Potential benefit: This work could enable opioid medicines that relieve pain with fewer risks such as addiction and respiratory depression.

How similar studies have performed: Preclinical and early human work on pathway-selective (biased) opioid drugs has shown promise for keeping analgesia while reducing side effects, but definitive clinical success is still limited.

Where this research is happening

Stanford, United States

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.