Study: Slow Release Ketamine Tablets Effective in Treating Severe Depression
Last reviewed and updated: September 1, 2026.
The short answer: A Phase 2 trial found an extended-release ketamine tablet beat placebo for treatment-resistant depression, with little of the dissociation that makes clinic monitoring necessary. It is promising and it is not available. R-107 remains investigational.
Depression is a serious mental health problem that affects millions of people. Traditional treatments, like antidepressants and therapy, often don’t work for everyone. One line of research is testing slow-release ketamine tablets. These are distinct from the compounded oral ketamine used in at-home ketamine treatments. This article explains the research behind this new treatment, how it works, and why it could be a game-changer for people with severe depression.
| Key takeaway | Detail |
|---|---|
| The trial | 168 patients with treatment-resistant depression, randomized across four doses plus placebo, published in Nature Medicine in 2024 |
| The result | At the 180mg dose, MADRS scores fell about 14 points against 8 for placebo, a difference of 6.1 points at 13 weeks |
| Relapse | 70.6% on placebo relapsed during blinded treatment, against 42.9% at 180mg |
| Why it matters | Minimal dissociation and no blood pressure changes, so the trial dosed at home rather than under two-hour clinic monitoring |
| The catch | R-107 is investigational. It is not FDA approved and cannot be prescribed today |
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The Promise of Ketamine Tablets for Depression
The Science Behind Slow-Release Ketamine Tablets
Slow-release ketamine tablets are designed to release the drug slowly into the bloodstream. This keeps a steady level of the drug in the body and avoids the “high” feeling that can come with ketamine. This way, patients get the benefits without feeling strange.
Clinical Trials and Their Findings
A recent study by the University of New South Wales and the Black Dog Institute tested slow-release ketamine tablets on 168 patients with severe depression. The patients were divided into five groups: four got different doses of ketamine, and one got a placebo. The results were promising. The group with the highest dose had a big drop in depression symptoms compared to the placebo group.
How Effective Are Ketamine Tablets?
The study used a tool called the Montgomery-Åsberg Depression Rating Scale (MADRS) to measure how well the tablets worked. Patients in the highest dose group had a 14-point drop in their MADRS scores, while the placebo group had an 8-point drop. This shows that slow-release ketamine tablets can really help people with severe depression.
Safety and Tolerability
In the trial, the slow-release formulation produced minimal dissociation and sedation, no blood pressure changes, and was taken at home rather than in a clinic. That is the practical advantage researchers point to, since injectable and nasal forms require roughly two hours of supervised monitoring. It is not a general safety clearance. R-107 is an investigational drug that has completed Phase 2 and is not approved or available by prescription.
Comparing Ketamine Tablets to Other Treatments
While traditional treatments like antidepressants and therapy are still important, ketamine tablets offer a new option for people who don’t respond to these methods. If approved, the tablet form would be easier to administer than IV ketamine. It is not yet an option a patient can choose.
The Future of Ketamine in Depression Treatment
The success of slow-release ketamine tablets in studies is a big step forward. Future research will look at the long-term effects of these tablets, how well they work for different people, and how they compare to other forms of ketamine, like nasal sprays and injections.
What the Study Actually Found
The trial was run by researchers at UNSW Sydney and the Black Dog Institute and published in Nature Medicine in 2024. It tested R-107, an extended-release ketamine tablet, against placebo in 168 people with treatment-resistant depression.
The 180mg dose taken twice weekly performed best. MADRS scores in that group fell by roughly 14 points from a baseline near 30, against 8 points on placebo, a least-squares mean difference of 6.1 points at 13 weeks. Relapse during blinded treatment followed a dose response, from 70.6 percent on placebo down to 42.9 percent at the top dose.
Where This Is Not Yet a Treatment Option
Phase 2 establishes a signal worth pursuing. It does not establish approval. R-107 has not cleared Phase 3, has no FDA approval, and cannot be prescribed. Anyone reading this as something to ask a clinic about today will be disappointed.
It is also worth separating this from the compounded oral ketamine already sold through telehealth. Those are lozenges or troches made by compounding pharmacies, not R-107, and they have not been through this trial process. The route comparison between esketamine and IV ketamine is a better guide to what is available now.
