For many people living with treatment-resistant depression (TRD), ketamine therapy works. Symptoms lift, sometimes within hours. The challenge is keeping them at bay. Standard IV ketamine infusions typically require multiple sessions over several weeks, with periodic maintenance visits to sustain the benefits. Each session means time away from work, travel to a clinic, and the cumulative cost of ongoing care.
That’s why a recent Phase I trial from Alar Pharmaceuticals is worth paying attention to. Their experimental drug, ALA-3000, is a sustained-release ketamine injection designed to deliver steady, low-level ketamine over weeks rather than hours. Early results suggest it may reduce how often people need treatment while still providing meaningful symptom relief.
Here’s what the research shows, what it means for people exploring ketamine therapy, and what still matters most regardless of how the science evolves.
ALA-3000: a sustained-release ketamine injection
ALA-3000 is a subcutaneous (under the skin) injection that releases ketamine slowly over several weeks. Unlike standard IV ketamine, which delivers the medicine directly into the bloodstream over about 40 minutes, ALA-3000 is designed to avoid the sharp plasma peaks that cause common side effects like dissociation (a temporary feeling of detachment from your body or surroundings) and sedation.
In Alar’s Phase I trial (NCT06965569), participants received two subcutaneous injections of ALA-3000 (at either 150mg or 250mg doses) or a placebo, spaced one week apart, while continuing their existing oral antidepressant. The trial was randomized, double-blind, and placebo-controlled. Alar announced the results in April 2026.
The findings, as reported by Clinical Trials Arena:
- ALA-3000 met its primary safety endpoint. All treatment-related side effects were mild to moderate, with no participants dropping out.
- Depression scores on the Montgomery-Åsberg Depression Rating Scale (MADRS) decreased as early as 24 hours after dosing. Improvements held from day 9 through day 36.
- In the 150mg group, MADRS scores dropped roughly 3 to 6 points more than placebo. In the 250mg group, the reduction was about 2 to 4 points greater.
- Response rates reached 60% or higher in the 150mg group and up to 69% in the 250mg group, compared with 36% to 45% for placebo.
- Plasma ketamine levels rose gradually without the sharp spikes associated with standard infusions, and no dose dumping occurred.
These are early numbers from a small Phase I safety trial, not a definitive efficacy study. But the direction is encouraging: sustained ketamine exposure over weeks, fewer side effects, and measurable symptom improvement that lasted more than a month after just two injections.
Alar Pharmaceuticals describes ALA-3000 as currently the longest-release ketamine product in development. The company is evaluating whether to move into later-stage clinical trials or pursue global licensing partnerships, per its pipeline page.
The science behind extending ketamine’s benefits
ALA-3000 isn’t the only research pushing toward longer-lasting ketamine effects. Two other recent studies help explain why this goal is within reach.
Visualizing ketamine’s effect on the brain
For years, researchers knew ketamine worked fast against depression but lacked a clear picture of what it actually changed inside the human brain. A study from Yokohama City University, published in Molecular Psychiatry in March 2026, addressed that gap directly.
Professor Takuya Takahashi’s team used a new PET imaging tracer called [¹¹C]K-2 to visualize AMPA receptors (proteins involved in brain cell communication and connection-forming) in patients with treatment-resistant depression receiving ketamine. They found that ketamine altered AMPA receptor density in specific brain regions, and those changes correlated with improvements in depressive symptoms.
“Ketamine’s antidepressant effect in patients with TRD is mediated by dynamic changes in AMPAR in the living human brain,” Professor Takahashi stated. This was the first direct visualization of ketamine’s molecular mechanism in living patients, rather than inferences drawn from animal models.
Why this matters for long-acting formulations: if ketamine’s benefits stem from AMPA receptor changes that promote neuroplasticity (the brain’s ability to form new connections), then maintaining steady ketamine exposure could sustain those changes longer than a single infusion allows.
From one week of relief to two months
A study from Vanderbilt University, published in Science in May 2025, showed in preclinical experiments that ketamine’s antidepressant effects could be extended from roughly one week to up to two months. Researchers led by Lisa Monteggia and Ege Kavalali used a drug called BCI that inhibits a specific protein phosphatase, keeping a signaling pathway (ERK) active longer. ERK activity appears to sustain the synaptic plasticity that drives ketamine’s prolonged antidepressant effects.
“When infused at a low dose, ketamine shows remarkable efficacy as a rapidly acting antidepressant, with effects observed within hours even in patients who have been resistant to other antidepressant treatments,” the Vanderbilt team noted. Their work suggests the brain’s repair mechanisms, once activated by ketamine, can be maintained if the right molecular conditions persist.
This is still preclinical (animal model) research. But it gives a biological rationale for why longer-lasting ketamine formulations could work in the first place.
What this could change for people living with TRD
Treatment-resistant depression affects roughly 30% of the nearly 280 million people worldwide living with depression, according to World Health Organization estimates cited by Alar Pharmaceuticals. For these individuals, standard antidepressants haven’t brought adequate relief after two or more medication trials.
Current IV ketamine therapy for depression typically involves an initial series of six infusions over two to three weeks, followed by maintenance sessions every few weeks or months. Each visit usually requires a few hours at a clinic, including post-infusion monitoring.
If long-acting formulations like ALA-3000 advance through later-stage trials and eventually gain approval, the treatment experience could shift in a few concrete ways. Fewer clinic visits would mean less time and travel for people balancing treatment with work and family life. Reduced side effects from avoiding rapid plasma peaks could make the experience more comfortable. And longer-lasting symptom relief, potentially over a month from just two doses, would mean more time spent living and less time in active treatment.
There’s also an important caveat. Phase I trials are designed primarily to test safety, not to prove efficacy in a larger population. ALA-3000 still needs Phase II and Phase III trials before any regulatory approval, and that process takes years.
What hasn’t changed: the foundation of good ketamine care
New formulations are worth watching. But regardless of how ketamine is delivered, the fundamentals of safe, effective treatment stay the same.
Medical screening and oversight
Ketamine therapy requires thorough medical evaluation before treatment begins. A care team should review your blood pressure, heart rate, cardiovascular history, and current medications. Certain conditions, such as uncontrolled hypertension, active substance use disorders, or a history of psychosis, may require additional evaluation or alternative approaches.
During treatment, IV ketamine gives clinicians the ability to adjust dosing in real time based on your response. A physician can slow, pause, or modify an infusion minute by minute. That kind of precision is one reason IV administration remains the clinical standard for treatment-resistant depression, and it’s something a subcutaneous depot injection doesn’t offer in the same way.
Preparation and integration
Medicine is a catalyst, not a cure-all. Research consistently shows that ketamine can open a window of neuroplasticity where new patterns of thinking and feeling become possible. Walking through that window requires work.
Preparation involves setting intentions, understanding what to expect, and creating conditions for the experience to be meaningful. Integration is the process of translating insights from a ketamine session into lasting behavioral change. It’s what separates temporary relief from durable transformation.
Even if long-acting formulations reduce the frequency of dosing, they won’t replace the need for this structured therapeutic support. A longer-lasting medicine still needs a person ready to use the window it opens.
Set and setting
The environment where you receive treatment matters. A calm, supportive clinical setting with trained professionals present contributes to safety and shapes the quality of the experience. This is true for IV infusions today, and it would remain true for any new formulation.
Choosing a ketamine provider while the science develops
While long-acting ketamine formulations move through clinical development, effective treatment is available now. When evaluating providers, a few things matter most.
Your care team should include physicians or nurse practitioners who monitor you throughout each session and can adjust treatment in real time. Nushama’s physician-led program maintains this standard for every member. Look for programs that include dedicated preparation and integration sessions, not just the infusion itself. IV ketamine offers the most reliable dosing and the strongest evidence base for treatment-resistant depression; at-home or oral options can be less predictable. And ask about outcomes data, response rates, and how the program defines success.
If you’re exploring ketamine therapy for treatment-resistant depression, anxiety, PTSD, or related conditions, the right starting point is a conversation with a qualified care team. Speak with our care team to discuss whether ketamine therapy may support your goals.
FAQs
What is long-acting ketamine?
- Long-acting ketamine refers to sustained-release formulations designed to deliver ketamine gradually over days or weeks, rather than all at once during a single infusion. ALA-3000, currently in Phase I clinical trials by Alar Pharmaceuticals, is one example. It’s a subcutaneous injection that maintains steady ketamine levels in the bloodstream, potentially reducing the need for frequent dosing and lowering certain side effects.
How is ALA-3000 different from standard IV ketamine?
- Standard IV ketamine is infused directly into the bloodstream over about 40 minutes, producing rapid plasma peaks that can cause temporary dissociation and sedation. ALA-3000 is injected under the skin and releases ketamine slowly, avoiding those sharp peaks. In its Phase I trial, it showed symptom improvement lasting over a month from just two injections, with only mild to moderate side effects reported.
When will long-acting ketamine be available to patients?
- ALA-3000 has completed Phase I testing. Before it could become available, it would need to pass Phase II and Phase III clinical trials and receive regulatory approval, a process that typically takes several years. No long-acting ketamine formulation is currently approved for clinical use.
Is IV ketamine still the most supported option for treatment-resistant depression?
- Yes. IV ketamine remains the most well-studied and clinically supported form of ketamine therapy for treatment-resistant depression. It allows real-time dose adjustments, has the strongest published evidence base, and provides rapid symptom relief, often within hours. Long-acting formulations may eventually offer additional options, but they are still in early clinical development.
What should I look for in a ketamine therapy provider?
- A strong program includes physician-led medical oversight, thorough screening before treatment, real-time monitoring during sessions, and structured preparation and integration support. The provider should use evidence-based protocols and be transparent about outcomes and safety measures.