Ketamine is being used to treat chronic pain when other options haven’t worked. At Stanford Pain, Dr. Theresa Lii is leading clinical care and research to better understand how it helps—and who it helps most. Stanford’s research efforts have been instrumental in shaping the understanding of ketamine’s role in pain management, with Dr. Lii at the forefront of these efforts.
A New Path Forward for People Living with Pain
Ketamine is a medicine often used in anesthesia, but it has also shown promise for people with chronic pain—especially when other treatments have failed. At Stanford Pain Medicine, Dr. Theresa Lii helps patients explore whether ketamine is the right next step in their pain care. As one of the leaders in ketamine research, Dr. Lii’s work has helped uncover unique findings that are expanding the boundaries of what we know about ketamine’s potential.
"We don’t fully understand how ketamine works for pain,” Dr. Lii explains. “But we believe it helps change the way the brain experiences pain.”
Stanford’s research has shown that ketamine’s effects are not just about blocking pain but also about reprogramming the brain's pain pathways through neuroplasticity. This insight is helping to shape the future of pain management by offering a fresh approach to treating chronic pain.
How Does Ketamine Help with Pain?
Chronic pain sometimes continues long after an injury has healed. That’s because the brain keeps sending pain signals, even when the body is no longer in danger. Ketamine may help “rewire” these pain pathways in the brain, through a process called neuroplasticity—a kind of brain reset. It may also boost the body’s natural pain-relieving system, called the endogenous opioid system. This is different from taking opioids; instead, ketamine helps the body use its own built-in pain control more effectively.
Stanford’s research has demonstrated that ketamine’s neuroplastic effects may be particularly valuable for patients with conditions where traditional treatments have failed. For example, patients suffering from complex regional pain syndrome (CRPS) or neuropathic pain may benefit more from ketamine’s ability to reset the brain’s pain networks. This discovery has contributed to the growing interest in ketamine as an alternative treatment for these difficult-to-treat conditions.
Ketamine for Pain and Mood Study
Dr. Lii is conducting a clinical study to better understand how ketamine can help those suffering from chronic pain. The study is looking for participants who experience chronic pain and current symptoms of depression. Participants will receive a 40-minute IV infusion of ketamine or a placebo while they are sedated with propofol, a medication commonly used to induce sedation for medical procedures. Researchers want to explore whether ketamine still has pain-relieving and mood-enhancing effects even when participants are unaware which treatment they received under sedation.
Who can join?
- Chronic pain sufferers with depression
Who cannot join?
- Those without depression
- Individuals with severe medical conditions, such as heart or kidney disease
Who Benefits from Ketamine?
Not everyone responds to ketamine the same way. According to Dr. Lii, most patients fall into one of three groups:
- Some feel better only during the infusion, with pain returning soon after.
- Others get relief that lasts for a few days or weeks.
- About 30–50% of patients feel better for months at a time.
Stanford’s research is helping answer why these differences exist. Dr. Lii and her team are studying factors like inflammatory markers and patient history to better predict who will respond to ketamine. Their findings may lead to more personalized approaches to ketamine therapy, ensuring that patients receive the most effective treatment based on their unique characteristics.
Researchers at Stanford and around the country are studying why some people respond better than others. Until we have those answers, Stanford Pain specialists help patients weigh the potential benefits based on their pain history and personal goals.
Why Are Stanford’s Ketamine Infusions Longer?
Many outpatient clinics offer ketamine for depression in short sessions—typically 30 to 40 minutes. But research suggests that these shorter infusions may not be as helpful for chronic pain. At Stanford, patients can receive ketamine during a five-day hospital stay, with the infusion running continuously. This extended treatment gives the brain more time to reset its pain signals.
“We’ve found that patients who receive a longer, continuous infusion tend to have better outcomes.”
“We’ve found that patients who receive a longer, continuous infusion tend to have better outcomes,” says Dr. Lii. This is one of the unique findings from Stanford’s ongoing research, which suggests that a longer, more sustained exposure to ketamine may be crucial for its effectiveness in chronic pain treatment.
What Are the Downsides of Ketamine?
The biggest challenge is cost. Because not every patient benefits from ketamine—and because more large-scale studies are required—some health insurance plans consider ketamine “experimental” and may not cover it. This makes treatment expensive, especially with a hospital stay. That’s why Stanford is also focused on advocacy and research: to improve access and show insurers what works.
Can Ketamine Be Combined with Other Treatments?
Yes. Some research suggests that ketamine may work even better when combined with other therapies that also target the brain. One promising option is transcranial magnetic stimulation (TMS), a non-invasive therapy that uses gentle magnetic pulses on the head. Like ketamine, it may help “rewire” pain circuits in the brain. Early studies suggest that using both together may improve outcomes and make relief last longer.
Stanford’s pioneering research is exploring the combined effects of ketamine and TMS, uncovering how these treatments can complement each other to offer even greater relief for chronic pain sufferers. These studies are showing early signs of promise and could open up new avenues for treatment.
Is Ketamine Right for Me?
If you’ve tried other treatments and are still living with chronic pain, ketamine may be worth exploring. It isn’t the right fit for everyone—but it can be life-changing for some.
At Stanford Division of Pain Medicine, Dr. Lii and the team will work with you to create a personalized care plan, whether or not ketamine is part of it. And because we’re also at the forefront of research, we’re helping shape what future pain care looks like—for everyone.
