In brief
- A pilot study from the University of California, San Diego (UCSD) is the first to test psilocybin for phantom limb pain.
- Nine amputees received either a single 25 mg dose of psilocybin or 100 mg of niacin as a comparator.
- Data published in The Journal of Pain suggest a potential reduction in pain, though the sample size is too small to draw firm conclusions.
A team at the University of California, San Diego, has published the first clinical trial testing psilocybin for phantom limb pain—the persistent, painful sensation in a missing body part that affects the vast majority of amputees. This small, exploratory study was primarily designed to determine whether the substance is well-tolerated in this patient group, rather than to prove its efficacy.
Pain that current treatments fail to resolve
Phantom limb pain often becomes chronic despite a wide variety of drugs and therapies, and many patients never find satisfactory relief. The team, led by Jon G. Dean alongside pain specialists Timothy Furnish and Joel Castellanos, proposed psilocybin as a path to explore due to its known ability to promote neuroplasticity and alter—even if only temporarily—how the brain interprets sensory signals that no longer have a physical origin.
Nine participants, one dose, four weeks of follow-up
The trial, registered as NCT05224336, included nine people with an amputation and persistent phantom pain, with an average age of 37. Five received a single oral dose of 25 mg of psilocybin, and four took 100 mg of niacin, chosen as a comparator because it causes a skin flush that helps maintain the study’s blinding. Each dosing session was supported by three preparation meetings and one subsequent integration session. In the following weeks, those who received psilocybin reported a reduction in pain intensity of more than 30% at two and four weeks in their personal logs. The authors themselves urge caution with this data: with so few participants, and given that many were able to guess which substance they had received, the result may be partly due to this “functional unblinding” rather than the actual effect of the molecule.
What this implies
Regarding safety, there were no serious adverse events or increased suicidal ideation in any participant. Two people experienced nausea and three had headaches; there were also transient episodes of anxiety and discomfort, along with temporary spikes in blood pressure and heart rate that resolved on their own before discharge. This is a factor to consider for anyone evaluating this path who has pre-existing cardiovascular conditions, and it aligns with what we already know about the sympathetic response to high-dose psilocybin. The authors insist that this is a feasibility study, not an efficacy study: nine people is too small a sample to claim anything about whether the substance relieves this type of pain, and a larger, better-blinded trial will be needed to know for sure. Even so, it is the first clinical data published on this specific combination, and it adds to a line of research that is beginning to look beyond depression to explore psilocybin in various chronic pain conditions—a field we also cover in our report on psilocybin and mushrooms. Those who wish to manage this information using harm reduction criteria can consult our section on harm reduction and responsible use. It is the same shift we saw in the Yale pilot trial for migraines: psilocybin is beginning to be tested for pain, not just depression.
Source
- Dean, J.G. et al. Feasibility and Tolerability of Psilocybin for Phantom Limb Pain. The Journal of Pain, August 7, 2026.
Educational content written from a harm reduction perspective and with respect for individual freedom. It is not a substitute for advice from a healthcare professional and is not intended to encourage or condemn any drug use.
