A Tiny Ketamine Trial Hints at Fatigue Relief, and Asks More Questions Than It Answers

Fatigue is one of those symptoms medicine has never quite known what to do with. It rides along with cancer, lupus, fibromyalgia, and the condition still awkwardly labeled chronic fatigue syndrome, and for many people it outlasts the disease that brought it. Stimulants help a little. Sleep advice helps a little. Mostly patients are told to pace themselves and wait. So when a drug already known for lifting treatment-resistant depression gets pointed at fatigue, it is worth a careful look.

A research team led by Taichi Goto and Leorey N. Saligan at the National Institutes of Health ran a small experiment to ask exactly that question [2]. The results were published in Pharmacological Reports under a deliberately modest title: a preliminary proof-of-concept trial [1]. The modesty is earned. This was a first probe, not a verdict.

Here is what they did. Ten adults living with persistent fatigue from a mix of underlying conditions came through a randomized, double-blind crossover design. Each person received two 40-minute intravenous infusions, separated by a two-week washout. One infusion was a low dose of ketamine. The other was midazolam, a sedative chosen as the comparison drug. Crossover means everyone served as their own control, getting both treatments in a randomized order, which is a sensible way to squeeze information out of a small group. The researchers then tracked fatigue scores over the following days.

The headline number is genuinely interesting. The day after the ketamine infusion, participants reported their fatigue had dropped by nearly 39 percent [1]. That is not a subtle nudge. By the third day, the ketamine effect had settled to around a 21 percent reduction. If you stopped reading there, you might come away convinced.

But the comparison drug refused to play the supporting role assigned to it. Midazolam produced a fatigue reduction of close to 18 percent over the same window. The gap between the two drugs never reached statistical significance. In plain terms, the study could not confidently say ketamine beat the sedative. When the thing you expect to be a placebo-like control starts performing almost as well as the active treatment, the story gets complicated fast.

Why would a sedative ease fatigue? One possibility the authors raise is that midazolam carried unexpected anti-inflammatory activity, which muddies any clean read of what ketamine alone was doing. Inflammation is a leading suspect in the biology of chronic fatigue, so a comparison drug that quietly nudges inflammation is not a neutral yardstick. It is a second variable. The same inflammatory thread runs through depression research — a parallel proof-of-concept trial recently found that targeting interleukin-6 to calm inflammation may lift treatment-resistant depression, which hints at overlapping biological mechanisms across mood and fatigue disorders.

There is also the crossover design's built-in hazard. Because each participant took both drugs, effects from the first infusion can spill into the second phase even after a washout period. The researchers saw signs of exactly this carryover, which made the second half of the data harder to interpret. A two-week gap sounds generous, but it may not be long enough to fully reset a person's fatigue baseline, especially when the underlying illness is still active.

So how much should any of this move us? Not far, and the authors would agree. Start with the size. The trial aimed to enroll 60 people and managed 10. A study that small is statistically underpowered almost by definition. It can detect a dramatic effect, but it has very little power to rule one in or out with confidence, and it is exquisitely sensitive to a single unusual responder. Four participants started on ketamine and six started on midazolam, so even the randomization was lopsided.

The blinding deserves its own flag. Ketamine produces noticeable dissociative sensations, the floaty, disconnected feeling that makes it hard to disguise. Both participants and clinicians in this trial were often able to guess correctly which drug had been given. Once people know what they received, expectation can shape how they rate something as subjective as tiredness. A double-blind trial only works while the blind holds, and here it leaked.

Then there is the sample itself. The ten participants did not share one diagnosis. They carried fatigue from cancer, fibromyalgia, lupus, and ME/CFS, conditions with different underlying biology. Pooling them increases the odds of finding any fatigue at all to study, but it weakens any claim that a finding applies to a specific patient group. What helps lupus fatigue may do nothing for cancer-related fatigue, and a study this size cannot tease those threads apart. The same challenge of heterogeneous patients with overlapping diagnoses is familiar from mood disorder research — work on how shame and abandonment beliefs cluster differently in bipolar disorder with and without borderline traits faces a similar problem of mixed presentations in the same clinical group.

What, then, is the honest takeaway? A signal worth chasing. The rapid, large drop in fatigue the day after ketamine echoes the speed seen in its antidepressant effects, and that pattern is suggestive enough to justify a real trial. The value of this work is in what it sets up rather than what it settles. It gives future researchers a dosing protocol, a sense of the timeline to watch, and a clear warning that midazolam is the wrong comparator and that blinding will be a stubborn problem.

For now, ketamine for fatigue sits where a lot of promising ideas sit early on. The biology is plausible, the first data point is eye-catching, and the study that produced it is too small and too leaky to lean on. That is not a failure. It is what a proof-of-concept is supposed to look like, including the parts that complicate the hopeful version. For more coverage of emerging mental health treatments and mood research, the field is moving fast even when individual studies stay modest.

Sources

1. Goto, T., Kreskow, J. D., Ross, A. L. R., Blumhorst, C. L., Zhao, J. J., Mannes, A. J., Bačkonja, M., Zarate, C. A., Jr., & Saligan, L. N. (2025). A preliminary proof-of-concept trial on the effects of ketamine on fatigue: a randomized crossover trial. Pharmacological Reports. https://doi.org/10.1007/s43440-025-00808-4
2. MedicalXpress. (2026, February 12). Ketamine may fight chronic fatigue, study suggests. https://medicalxpress.com/news/2026-02-ketamine-chronic-fatigue.html

This article summarizes published research for general informational purposes only. It is not medical advice and should not be used to guide treatment, diagnosis, or other health decisions. Speak with a qualified healthcare professional about any health concern.