TL;DR
- •The most common first-session side effects are nausea, transient blood pressure rise, dissociation intensity that feels unfamiliar, and mild grogginess for 60-90 minutes after dosing — all typically self-limited and manageable.
- •Nausea is the most reported side effect; pre-medication with ondansetron and a light pre-session meal sharply reduce its likelihood and severity.
- •Blood pressure and heart rate rise modestly (typically 10-20 mmHg systolic) during the peak, then return to baseline within 60-90 minutes. Patients with controlled blood pressure tolerate this well; uncontrolled hypertension is screened pre-treatment.
- •Dissociation itself isn't technically a "side effect" — it's the therapeutic experience. But unfamiliar intensity in the first session can feel like a side effect; preparation and dose calibration address this.
- •Lingering grogginess for 1-2 hours after the dose is normal; full cognitive recovery by bedtime, normal function the next morning.
- •Serious adverse events are rare in supervised sublingual ketamine; meta-analytic safety data place the profile favorably against most psychiatric medications for treatment-resistant depression.
- •If something feels off, you can stop, sit up, drink water, or contact your care team during the session. The protocol is responsive, not rigid.
Step by step
- 1
Pre-session prevention (the hour before)
Light meal 2+ hours before reduces nausea risk substantially — empty stomach is harder, very full stomach is also harder; light is best. If you have a history of motion sickness or strong nausea response to medications, your physician can add ondansetron (a standard anti-nausea medication) 30 minutes before the dose. Water nearby. Comfortable clothes.
- 2
During the session — nausea
If nausea occurs, it typically arrives during the onset (first 15-30 minutes) and resolves as the peak progresses. Lying still rather than moving the head reduces it. Sipping water can help; full eating during the session usually makes it worse. If significant, the session can continue safely; if intolerable, future sessions add ondansetron pre-medication or adjust the dose.
- 3
During the session — blood pressure
Mild rise (10-20 mmHg systolic, sometimes more) during the peak is expected. You may notice your heart beating more noticeably or a warm sensation. This isn't dangerous in patients screened for hypertension. The rise resolves over 60-90 minutes as the medication metabolizes. Tovani pre-screens for uncontrolled hypertension and cardiovascular disease specifically to keep this safe.
- 4
During the session — dissociation intensity
Even when expected, the first dissociative experience can feel surprising. Common: visual changes more vivid than anticipated, time distortion, sense of distance from the body. If it feels intense, the eye mask and music help contain the experience; breathing slowly through it helps. Most patients describe initial surprise giving way to curiosity within minutes. Future sessions feel more familiar.
- 5
Recovery phase (60-90 minutes post-dose)
Grogginess, mild unsteadiness, soft cognitive function. You can talk and walk but you're not at full operating capacity. Stay seated or lying; let someone help you to the bathroom if needed. Water and a light snack are fine. NO driving, no important decisions during this window.
- 6
Evening and next morning
Most side effects resolve by bedtime. The next morning, full cognitive function is back — you can drive, work, make decisions. Persistent next-day grogginess is uncommon and should be mentioned to your physician for dose review.
What this actually feels like
For most patients, first-session side effects are mild and pass quickly. Nausea, when it happens, feels like motion sickness — uncomfortable but contained, often resolving within 15-30 minutes especially when lying still. The blood pressure rise is usually not consciously noticed; some patients feel a warmth or awareness of their heartbeat that fades. The dissociation can feel unfamiliar — like the room is "further away" or like you're watching your thoughts rather than thinking them — but this is the experience, not a problem with it. The 60-90 minute recovery feels like coming out of a deep meditation or a long nap: soft, gentle, slightly slow. The morning after typically feels normal, sometimes lighter than usual.
Timeline
Onset of side effects: within 15-30 minutes of dosing alongside the therapeutic effect. Peak intensity: 30-45 minutes. Resolution: 60-90 minutes for dissociation and grogginess; 60-120 minutes for blood pressure / heart rate. By bedtime, most patients are essentially back to baseline. Next-morning effects are rare; if persistent grogginess or nausea continues into day 2, the dose or pre-medication is adjusted for future sessions.
Common concerns, addressed
“What if I vomit during the session?”
Rare with pre-session preparation but possible. If it occurs, sit upright, sip water slowly, signal your care team. The session can continue safely after; future sessions add ondansetron pre-medication and may adjust the dose. Vomiting doesn't mean the treatment isn't working — it's a manageable side effect, not a treatment failure signal.
“I have anxiety about my blood pressure rising”
Tovani pre-screens cardiovascular risk specifically to identify patients who shouldn't do unsupervised at-home protocols. If you've passed screening, your blood pressure is in a range where the modest peak rise is well-tolerated. If you have a home blood pressure cuff and the data calms you, checking before the session is fine; checking during the peak is not necessary and usually counterproductive.
“The dissociation in my first session felt too intense”
Common feedback that future sessions address. Dose calibration, more thorough intention-setting, music adjustment, or a slower onset protocol (titration over 2-3 initial sessions) all help. Tell your physician at the post-session check-in; the protocol is meant to be adjusted to your response, not pushed through.
“How long am I groggy?”
60-90 minutes for most patients, 90-120 for some. Full cognitive function by bedtime; normal function the next morning. If grogginess persists past day 1 or into day 2, mention to your physician — dose review or schedule adjustment usually resolves it.
“I read about urinary issues with ketamine — should I worry?”
Urinary tract issues are documented with chronic recreational ketamine use (daily, high-dose, over months-years), not with supervised episodic therapeutic dosing at much lower doses. The exposure pattern is fundamentally different. Tovani's monthly maintenance dosing has not been associated with urinary issues in current published evidence. Persistent urinary symptoms during treatment should be reported to your physician.
“Will side effects get worse with more sessions?”
Usually the opposite — most patients report side effects diminishing across the first 2-3 sessions as the experience becomes familiar and dose is calibrated. Nausea, dissociation surprise, and post-session grogginess often become noticeably milder by session 3-4. Side-effect intensification across sessions is uncommon and warrants protocol review.
Who this fits best
Sublingual ketamine's side-effect profile fits patients with controlled blood pressure, no significant cardiovascular disease, no history of severe nausea response to medications (or willingness to use ondansetron pre-medication), and willingness to experience an unfamiliar altered state. Patients with severe motion sickness, very labile blood pressure, or strong aversion to any altered consciousness may find the side-effect profile harder; for these patients, dose adjustment and slower titration usually help, though some prefer alternative modalities.
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Frequently asked
Will I feel sick during my first session?
Some patients do; many don't. Light eating 2+ hours before significantly reduces nausea risk. If you have a history of motion sickness or nausea-sensitivity, ondansetron pre-medication 30 minutes before the dose makes nausea unlikely. If nausea occurs, it typically passes within 15-30 minutes.
How much does blood pressure go up?
Modestly — typically 10-20 mmHg systolic during the peak, then back to baseline over 60-90 minutes. Tovani screens for cardiovascular conditions pre-treatment, so if you've been cleared, your blood pressure is in a range where this rise is well-tolerated.
Will I be impaired the next day?
No, for most patients. Cognitive function returns to normal by bedtime; the next morning you can drive, work, and make decisions. If persistent grogginess into day 2 occurs, mention to your physician — dose adjustment usually resolves it.
Is the dissociation a side effect or part of the treatment?
Part of the treatment, technically. Dissociation reflects the NMDA-glutamate mechanism that produces the rapid antidepressant effect. That said, the intensity of dissociation can feel like a side effect, especially the first time. Future sessions feel more familiar, and dose calibration adjusts intensity to your tolerance.
What about long-term side effects?
Therapeutic supervised dosing (sessions over weeks plus monthly maintenance) at clinical doses has favorable long-term safety per current evidence — distinct from chronic recreational high-dose use, which is associated with urinary tract and cognitive concerns. Tovani monitors response and side effects across the treatment course.
References
- Murrough JW et al. 2013, American Journal of Psychiatry. Ketamine RCT in treatment-resistant depression — characterized side-effect profile including transient blood pressure changes and dissociative symptoms during dosing window. PMID 23982301
- Sanacora G et al. 2017, JAMA Psychiatry. APA consensus on ketamine in mood disorders — addresses safety monitoring, blood pressure considerations, and adverse-effect management in clinical practice. PMID 28249076
- Guo H et al. 2025 — systematic review of ketamine/esketamine safety. Comparative safety meta-analysis — characterizes adverse-event profile of ketamine and esketamine in major depressive disorder, including dissociation, nausea, and cardiovascular effects. PMID 41235115
- Jelen LA et al. 2024 — clinical psychiatry practice guidelines for ketamine. Clinical guidelines for ketamine use — practical guidance on dose, monitoring, side-effect management, and patient preparation. PMID 38725375