Post-traumatic stress disorder (PTSD) can affect far more than memory. Trauma can alter the way the brain and nervous system respond to safety, threat, relationships, sleep, emotions, and even the body itself. For some people, traditional medications and psychotherapy provide significant relief. For others, symptoms remain despite years of treatment.
One emerging option receiving increased attention is ketamine, including ketamine administered by subcutaneous (SQ) injection.
Ketamine is not a new medication. It has been used in medicine for decades as an anesthetic. More recently, researchers have become interested in lower-dose ketamine because of its effects on mood, neuroplasticity, and potentially trauma-related symptoms.
It is important, however, to understand both sides of the conversation:Â ketamine may offer meaningful benefits for some people with PTSD, but the research is still evolving, particularly for subcutaneous administration.
Subcutaneous ketamine is given as an injection into the fatty tissue beneath the skin rather than directly into a vein or muscle.
Racemic ketamine is FDA-approved as an anesthetic for intravenous or intramuscular administration. Its use for psychiatric conditions such as PTSD—and the use of the subcutaneous route for this purpose—is considered off-label.
Off-label does not mean illegal or necessarily inappropriate. Medications are frequently prescribed off-label when a qualified clinician determines that there is sufficient clinical rationale for doing so. It does mean that patients should understand that the treatment has not been FDA-approved specifically for PTSD.
Research specifically examining SQ ketamine for PTSD is limited. Most controlled PTSD studies have evaluated intravenous ketamine, which means findings from one route cannot automatically be assumed to apply identically to another.
Ketamine can be administered by several different routes, and the route matters because the amount of medication reaching the bloodstream can vary significantly. This is known as bioavailability.
For example, 50 mg of ketamine given intravenously is not pharmacologically equivalent to 50 mg contained in a sublingual troche. Different routes have different rates of absorption and metabolism before the medication reaches systemic circulation.
Route | Approximate Bioavailability | What It Means |
Intravenous (IV) | ~100% | Medication is delivered directly into the bloodstream, providing the most predictable exposure. |
Intramuscular (IM) | ~90–95% | Ketamine is absorbed through muscle tissue and generally provides high and relatively predictable systemic exposure. |
Subcutaneous (SQ/SC) | ~80–95% | Ketamine is absorbed through the tissue beneath the skin and generally provides high systemic availability. |
Sublingual/Buccal Troche | ~20–30% | Ketamine is absorbed through the tissues of the mouth. Absorption can vary depending on administration technique and how much medication is swallowed. |
Oral/Swallowed Ketamine | ~10–30% | Ketamine undergoes significant first-pass metabolism in the liver, resulting in lower and more variable systemic exposure. |
These differences are important when selecting a treatment route and determining dosage. Ketamine doses should not be considered equivalent milligram-for-milligram across different routes of administration.
At Heart Mind Body, we chose the subcutaneous (SQ) route because it offers a practical balance of good bioavailability, ease of administration, patient comfort, and clinical simplicity.
SQ ketamine provides relatively high systemic absorption while avoiding the need for placement of an IV.
There are several practical reasons HMB selected this route:
·       Good and relatively reliable absorption: SQ ketamine provides substantially greater bioavailability than oral or sublingual administration.
·       No IV placement: Patients do not need an intravenous catheter, infusion pump, or traditional IV infusion.
·       Simple administration: The medication is administered as a small injection into the subcutaneous tissue.
·       Patient comfort: Avoiding IV access may be helpful for patients who have difficult veins, dislike IV placement, or find more medicalized treatment environments stressful.
·       Less equipment: SQ administration requires less equipment than a traditional IV infusion protocol.
·       Individualized dosing: The route can be incorporated into a carefully monitored treatment plan in which response, tolerability, and dosing are reassessed over time.
·       More gradual absorption than direct IV administration: Because ketamine must first be absorbed from the subcutaneous tissue, blood levels do not rise as instantaneously as they do when medication is delivered directly into a vein.
For HMB, SQ ketamine provides a way to combine good systemic absorption with a straightforward, patient-centered treatment experience while allowing patients to remain in a supportive clinical environment for monitoring and therapeutic integration.
It is important to recognize that SQ ketamine has not been proven to be clinically superior to IV or IM ketamine. Most psychiatric ketamine research has historically involved IV administration, and research specifically evaluating SQ ketamine—particularly for PTSD—is still developing.
For this reason, HMB approaches SQ ketamine as an individualized, off-label treatment option rather than as a replacement for established trauma-focused therapies.
Ketamine works differently from traditional antidepressants.
One of its primary actions involves the brain’s glutamate system, particularly NMDA and downstream AMPA receptor activity. These pathways are involved in communication between neurons, learning, memory, and neuroplasticity—the brain’s ability to form and reorganize neural connections.
This is especially interesting in PTSD because trauma can create powerful patterns of fear, avoidance, hypervigilance, and negative beliefs that become deeply reinforced over time.
Ketamine may temporarily increase the brain’s capacity for change. In practical terms, this has led researchers and clinicians to explore whether ketamine can create a therapeutic period in which rigid patterns become somewhat more flexible and new emotional learning may become easier.
Ketamine does not erase traumatic memories.
Rather, the goal is to help the nervous system develop a different relationship with those memories.
Traditional psychiatric medications often require several weeks before patients know whether they are helping.
Ketamine’s effects can occur much more quickly.
Clinical studies have reported reductions in PTSD symptoms following ketamine treatment, sometimes beginning relatively soon after administration. Some patients may also experience improvement in depression occurring alongside PTSD.
For someone who has struggled for years with intrusive memories, hyperarousal, avoidance, emotional numbness, or depression, even a temporary reduction in symptom intensity may create an important opportunity for further therapeutic work.
However, not every study has demonstrated the same level of benefit, and symptom improvement may not persist without additional treatment.
One of the most promising ways of thinking about ketamine is not necessarily as a stand-alone cure, but as a possible bridge into deeper therapeutic work.
When a person has lived in survival mode for years, the nervous system may respond to trauma-related material with overwhelming fear, shutdown, avoidance, or dissociation.
For some patients, ketamine may temporarily reduce the rigidity of these responses.
A carefully structured psychotherapy or integration session may then help the person explore emotions, beliefs, memories, relationships, and new perspectives that previously felt inaccessible.
The medication may open a window.
The therapeutic work helps determine what happens within that window.
Ketamine-assisted psychotherapy for PTSD remains an evolving area of research. Established trauma-focused treatments such as EMDR, Cognitive Processing Therapy, and Prolonged Exposure continue to have substantially stronger evidence for PTSD treatment.
Some people with PTSD have already tried antidepressants, therapy, lifestyle changes, and multiple combinations of treatments without experiencing the degree of improvement they hoped for.
Ketamine affects different neurobiological pathways than medications such as SSRIs and SNRIs.
For carefully selected patients, that different mechanism may provide another treatment option when conventional approaches have not been sufficient.
This may be particularly relevant when PTSD occurs alongside significant depression, although treatment decisions should always be individualized.
Ketamine alters perception and consciousness. Some of these effects may be therapeutic for certain individuals, while others may find them uncomfortable.
During or shortly after treatment, a person may experience:
·      Dissociation or feeling temporarily detached from the body or surroundings
·      Dreamlike sensations or altered perception
·      Dizziness or unsteadiness
·      Sleepiness or sedation
·      Nausea or vomiting
·      Temporary anxiety or emotional discomfort
·      Blurred or altered vision
·      Confusion or difficulty concentrating
·      Increased heart rate
·      Temporary increases in blood pressure
·      Tenderness or irritation at the injection site
Some people experience the altered state as peaceful or meaningful. Others may experience fear, agitation, or unpleasant perceptual changes.
This is one reason ketamine should be administered in an appropriately supervised clinical environment rather than treated casually as simply another medication injection.
The long-term psychiatric use of repeated ketamine is still being studied.
Potential concerns include:
Tolerance and dependence. Ketamine is a Schedule III controlled substance, and misuse, tolerance, and dependence can occur.
Urinary and bladder problems. Chronic or heavy ketamine exposure has been associated with urinary frequency, urgency, painful urination, cystitis, and other urinary tract complications.
Liver and biliary problems. Repeated or prolonged exposure has also been associated with liver and biliary abnormalities in some individuals.
Cognitive effects. Heavy or frequent misuse has been associated with problems involving attention and memory. The long-term risks associated with carefully supervised psychiatric treatment remain an area of ongoing study.
These risks reinforce the importance of thoughtful dosing, ongoing reassessment, and avoiding the assumption that treatment should simply continue indefinitely because a patient initially responds.
Before treatment, the clinician should conduct a careful medical and psychiatric assessment.
Particular attention may be needed for individuals with cardiovascular problems, significant blood-pressure concerns, history of psychosis or mania, substance-use concerns, pregnancy, significant liver or bladder problems, or medications and substances that could increase sedation or other risks.
Treatment should always involve informed consent and an opportunity for the patient to discuss both the potential benefits and reasonable alternatives.
This is where balance is especially important.
Several studies and systematic reviews have produced encouraging findings suggesting that ketamine may reduce PTSD symptoms relatively rapidly.
At the same time, the evidence is not yet strong enough for ketamine to be considered an established first-line treatment for PTSD.
Current PTSD treatment guidelines continue to prioritize evidence-based trauma-focused psychotherapy, and ketamine remains an emerging and off-label treatment option.
That does not mean research has stopped or that no patient can benefit.
It means that the scientific evidence is still developing.
Promising is not the same as proven.
Ketamine Should Be Part of a Treatment Plan—not a Promise
There is a natural desire to find the treatment that will finally make trauma disappear.
Ketamine should not be presented as a cure for PTSD.
For appropriately screened patients, it may provide another tool—particularly when symptoms have remained persistent despite conventional treatment. Its potential value may lie not only in symptom reduction but also in creating an opportunity for greater psychological flexibility and deeper therapeutic work.
The most thoughtful approach combines careful patient selection, informed consent, appropriate monitoring, psychotherapy when indicated, and ongoing evaluation of whether treatment continues to provide meaningful benefit.
Healing from trauma is rarely about replacing who a person is.
Sometimes it is about creating enough safety and flexibility for the nervous system to begin restoring what trauma taught it to protect.
This information is provided for educational purposes and is not a substitute for individualized medical advice. Ketamine treatment should only be considered after evaluation by an appropriately qualified healthcare professional.
About the Author
Leigh Geffken, MSN, PMHNP-BC
September 16, 2026
