KETAMINE HYDROCHLORIDE (Ketalar) Side Effects Guide

Table of Contents

Ketalar (Ketamine) Side Effects Guide: What to Expect and What’s Normal

Side Effects Overview Table

How Other Drugs Compare

Week-by-Week Timeline

Why Doctors Still Prescribe Ketalar (Ketamine)

The Worst Side Effects

The Most Common Side Effects

Deep Dive: Brain Fog, Memory Issues, and Slow Thinking

Deep Dive: Anxiety or Panic Attacks

Discontinuation & Withdrawal

Dosage by Condition

Alternatives

Clinical Trials

Decision Map

Monitoring & What to Track

Pregnancy & Breastfeeding

Emergency Warning Signs

Summary & Next Steps

Appendix A: FDA Label Data Summary

Appendix B: Reddit User-Reported Side Effects

Appendix C: Clinical Trials with Different Mechanisms

Appendix D: Methodology

Sources

Ketalar (Ketamine) Side Effects Guide: What to Expect and What’s Normal

Side Effects Overview Table

How Other Drugs Compare

Week-by-Week Timeline

Why Doctors Still Prescribe Ketalar (Ketamine)

The Worst Side Effects

The Most Common Side Effects

Deep Dive: Brain Fog, Memory Issues, and Slow Thinking

Deep Dive: Anxiety or Panic Attacks

Discontinuation & Withdrawal

Dosage by Condition

Alternatives

Clinical Trials

Decision Map

Monitoring & What to Track

Pregnancy & Breastfeeding

Emergency Warning Signs

Summary & Next Steps

Appendix A: FDA Label Data Summary

Appendix B: Reddit User-Reported Side Effects

Appendix C: Clinical Trials with Different Mechanisms

Appendix D: Methodology

Sources

A data-driven guide to Ketalar (ketamine) side effects, blending FDA trial results with real-world user reports. Severity, duration, and practical management tips included.

Medication: Ketalar (KETAMINE HYDROCHLORIDE) Drug Class: Antidepressant Author: Michael Baskerville Gill, B. Sc.

Reviewed by the Power Medical Content Team

Ketalar (Ketamine) Side Effects Guide: What to Expect and What’s Normal

Day 1: A surreal floaty feeling—or just a queasy stomach. Day 2: A wave of calm, maybe, or gnawing anxiety that lingers after the session. Day 7: Brain fog thick as soup, or a sense you might be seeing the world in color for the first time in months. If you're starting Ketalar (ketamine hydrochloride) for depression, you already know it's not your typical antidepressant. The standard playbook for SSRIs and SNRIs—wait six weeks, cross your fingers, endure whatever comes—doesn't quite apply here.

So why do doctors still reach for this drug that's as likely to send you floating as it is to raise your blood pressure? Because for some people, the alternatives just don't cut it. Standard antidepressants fail 30–40% of the time, and even when they "work," side effects like weight gain and sexual dysfunction can be a deal-breaker. Ketamine works differently—and so do its side effects. Let's get granular about what you might feel, what the numbers say, and what real patients wish they'd known on day one.

Interested in clinical trials? Many trials for depression now target different mechanisms than Antidepressant—potentially offering different side effect profiles. Browse clinical trials →

Side Effects Overview Table

Side Effect	FDA Rate	Reddit Reports	Severity	Duration	Example
Feeling detached from body (dissociation)	N/A	🟠 Frequent (7 posts)	🟢 Mild	30–60 min, resolves in 1–2h	source
Nausea and upset stomach	0%	🟠 Frequent (6 posts)	🟢 Mild	Waves for hours	source
Increased anxiety or nervousness	0%	🟠 Frequent (6 posts)	🟡 Moderate	Minutes to few hours	source
Feeling calm, relaxed, or drowsy (sedation)	0%	🟠 Frequent (5 posts)	🟢 Mild	Hours, up to a day	source
Brain fog, memory issues, slow thinking	0%	🟠 Frequent (5 posts)	🟠 Severe	Days to ongoing	source
Euphoric or happy feeling	0%	🟡 Occasional (4 posts)	🟢 Mild	Up to few hours	source
Dizziness or vertigo	0%	🟡 Occasional (4 posts)	🟢 Mild	Few hours	source
Vivid or visual hallucinations	12%*	🟡 Occasional (3 posts)	🟢 Mild	During session	source
Blurred vision	0%	🟢 Rare (2 posts)	🟢 Mild	Few hours	source
Headache	0%	🟢 Rare (2 posts)	🟢 Mild	Few hours	source
Episodes of rage or anger	0%	🟢 Rare (2 posts)	🟡 Moderate	Session duration	source
Panic attacks or intense panic	0%	🟢 Rare (2 posts)	🟡 Moderate	Session duration	source
Vomiting	0%	🟢 Rare (2 posts)	🟢 Mild	Few hours	source
High blood pressure	10%	🟢 Rare (2 posts)	🟢 Mild	During session	source
Muscle relaxation and calmness	0%	🟢 Rare (2 posts)	🟢 Mild	Session duration	source

→ View all 35 side effects from FDA trials → View all 15 user-reported side effects

How Other Drugs Compare

If you're weighing options, here's how Ketalar (Ketamine) stacks up against alternatives:

Metric	Ketalar (Antidepressant)	CYB003 (Psilocybin analog)	Osavampator (AMPA-PAM)	D-cycloserine (NMDA partial agonist)
MECHANISM
Drug class	NMDA receptor antagonist	Deuterated psilocybin analog	AMPA receptor positive allosteric modulator	NMDA receptor partial agonist
How it works	Blocks NMDA receptors (prevents reuptake of glutamate at synapses, disrupts normal signaling, induces dissociative state)	Activates 5-HT2A receptors (psychedelic effect; enhances serotonin signaling)	Boosts activity at AMPA receptors (enhances synaptic plasticity and neurotrophic effects)	Partially activates glycine site of NMDA receptor (modulates glutamate transmission)
EFFICACY
Response rate	Not established for depression	79% (3w, 16mg dose) source	Not yet reported (P3 ongoing)	Not reported
Remission rate	Not established	75% (4m, 16mg) source	Not yet reported	Not reported
Time to effect	Minutes-hours	1–3 weeks	Estimated faster than SSRIs	2–6 weeks
KEY SIDE EFFECTS
Dissociation/brain fog	🟠 40% (frequent, mild–severe)	🔵 None	🔵 None	🔵 None
Nausea/vomiting	🟠 40% (frequent, mild)	🟡 15–20% (mild-moderate)	🟢 Minimal	🟢 Minimal
Anxiety/panic	🟠 40% (frequent, mild–moderate)	🟡 10% (mild)	🟢 Minimal	🟢 Minimal
Sedation/fatigue	🟠 33% (frequent, mild)	🟢 None chronic	🟢 Minimal	🟢 Minimal
Weight gain	🟢 None	🟢 None	🟢 None	🟢 None
Sexual dysfunction	🟢 None	🟢 None	🟢 None	🟢 None

→ Find clinical trials matched to your situation

Week-by-Week Timeline

Week	Common Experiences	What's Normal	When to Call Your Doctor
Week 1	Dissociation, nausea, sedation, mild anxiety	Intense experiences during/after infusion	Severe anxiety, panic attacks, hallucinations that persist
Week 2–3	Brain fog, mood changes, sleep disturbance, calmness	Some lingering effects	Worsening depression, persistent brain fog
Week 4–6	May notice depression improvement, less acute side effects	Gradual mood change	No benefit, disabling brain fog, persistent anxiety
Week 6–8	Benefits plateau, residual side effects fade	Stable mood or gradual gain	Intolerable cognitive effects, persistent psychiatric symptoms

Most side effects peak in Week 1–2 and improve by Week 4. If you're still struggling at Week 8, it may be time to consider alternatives.

→ Explore clinical trials with faster onset

Why Doctors Still Prescribe Ketalar (Ketamine)

Ketamine works by blocking NMDA receptors (proteins on nerve cells that respond to glutamate, a brain chemical essential for learning and mood regulation). This blockade increases glutamate in the brain, producing a cascade of effects at synapses (gaps between nerve cells), rapidly lifting mood in some patients—sometimes within hours.

But these same NMDA-receptor gymnastics also mess with normal brain signaling, which is why you can feel spaced out, dissociated, or temporarily confused. The trade-off? For some, rapid depression relief. For others, a fog that lingers longer than the darkness it chased away. Doctors reach for ketamine when the standard playbook fails, because it offers a different mechanism with decades of safety data and mostly predictable, short-lived side effects. The trick is in balancing quick relief against a sometimes weird and wobbly aftermath.

The Worst Side Effects

"Horrible brain fog, zero short term memory, literally feel like a zombie." source

Reported as severe/debilitating by 2/5 users. Some describe being unable to drive or work for days.

Management tip:

Most providers recommend scheduling infusions on non-work days. Hydrate well and avoid stacking with other sedatives.
Persistent fog after repeated treatments? Discuss dose adjustments, spacing out sessions, or switching medications. Brain fog that doesn't lift may be a dealbreaker for some—see the Decision Map for alternatives.

Increased Anxiety or Panic

"After about an hour I experienced significant anxiety, which lasted for ~4 hours. Not panic attack levels, but levels that I haven't felt in many years." source "I was told what I experienced was common K. side effects: terror, panic, rage and crying constantly with vertigo and nausea." source

Reported as moderate or severe by 3/8 users (anxiety or panic). For most, it resolves within hours, but in some, it shadows several sessions.

Management tip:

Lowering the starting dose, having a support person present, using meditation or music, and (with medical clearance) benzodiazepines may help. Never mix with CNS depressants without professional supervision.

Dissociation/Detachment

"My arms and legs felt further away, and my body felt sort of numb, and my brain was mellower." source

Rated as mild by most (5/7), but a minority find the out-of-body sensation disturbing rather than fascinating. Grounding techniques (focusing on sensations, music, or a calm observer) may help re-anchor reality.

How Clinical Trials Compare

Clinical trial data for Ketamine in depression is limited, but Phase 2/3 studies for alternatives like CYB003 report much lower rates of cognitive impairment (none persistent), with transient headache (20%) and mild anxiety (10%) source. Osavampator and D-cycloserine so far show minimal chronic cognitive or dissociative effects compared to ketamine.

→ Find trials with lower rates of these side effects

The Most Common Side Effects

The top five most frequently reported side effects—by both Reddit users and the FDA label—are:

Dissociation (Feeling Detached from Body/Surroundings)
- Reddit: 7 users (mild)
- Timeline: Begins 10-15 minutes in, fades in 1-2 hours
- What helps: Calm, supportive setting; avoid driving, heavy machinery for several hours
- User quote: "During a high, which lasts about an hour, people might feel detached from their body, their emotions, or the world." source
Nausea and Upset Stomach
- Reddit: 6 users (mild)
- FDA: 0% in trials
- Timeline: During/after session, resolves within hours
- What helps: Pre-meds with ondansetron; small snack prior; lying still post-infusion
- User quote: "I'm also being hit with waves of nausea, but not throwing up." source
Anxiety/Nervousness
- Reddit: 6 users (moderate)
- FDA: 0% (though emergence reactions 12%)
- Timeline: During or after session, usually resolves within hours
- What helps: Guided meditation, reassurance, careful dose titration (gradual adjusting up)
- User quote: "After about an hour I experienced significant anxiety, which lasted for ~4 hours." source
Sedation/Drowsiness/Calm
- Reddit: 5 users (mild)
- Timeline: Several hours after session, sometimes a day
- What helps: Napping, avoiding heavy activity post-infusion
- User quote: "There is certain wonky grogginess that people experience for several hours after the session." source
Brain Fog, Memory Issues
- Reddit: 5 users (severe in 2)
- Timeline: Can last days or longer, especially with repeated use
- What helps: Extra rest, tracking memory/cognition, discussing dosing interval adjustments with prescriber
- User quote: "Horrible brain fog, zero short term memory, literally feel like a zombie." source

Deep Dive: Brain Fog, Memory Issues, and Slow Thinking

It's not the psychedelic swirl or the woozy nausea that torpedoes a workweek—it's the afterglow of brain fog, memory issues, and slow thinking. Reddit users say things like:

"I'm seriously suffering with what feels like brain damage. My cognition and thoughts are slow and disorganized. I can't drive very often or work anymore." source

This isn't the dreamy amnesia of a benzo. Some describe a zombie-like blankness that sets in after a series of infusions and refuses to lift. FDA trials (using the label's stricter definition) don't mention brain fog by name, but they do document emergence reactions—delirium, confusion, psychiatric symptoms—in about 12% of patients.

Management Tips:

If it lingers beyond a few days or worsens with repeat dosing, talk to your provider. Dosing intervals can sometimes be extended; some patients do better on lower doses or spaced-out sessions.
Cognitive remediation (brain training apps, puzzles), maximizing sleep, and careful monitoring may help.
Don't drive, operate machinery, or make big decisions until you're confident the fog has cleared.

For some, this side effect is the dealbreaker. If that's you, see the Decision Map for alternatives (CYB003, osavampator) with fewer cognitive complaints reported.

Deep Dive: Anxiety or Panic Attacks

If the stereotype is "calm, dreamy trance," plenty of patients report the polar opposite: surges of anxiety and even panic attacks. One person put it plainly:

"I was told what I experienced was common K. side effects: terror, panic, rage and crying constantly with vertigo and nausea." source

For most, these sensations rise during or right after the session and recede within hours. But they can overshadow the potential mood benefits if severe or unpredictable. The FDA lumps some of these under "emergence reactions," noted in 12% of patients, but the flavor and intensity vary widely between individuals.

What helps:

Some clinics offer calming music, dim lights, or guided support (yes, it matters!).
Pre-session anxiety management, gradual titration (starting low, going slow), and always informing your provider if you have a panic disorder history.
For severe panic, medication adjuncts (under medical supervision) are sometimes considered, but mixing with other sedatives is risky business.

If anxiety is an overwhelming feature, some newer clinical trial drugs show lower anxiety rates—check the Compare and Trials sections for more.

Discontinuation & Withdrawal

Unlike classic antidepressants, the FDA label for Ketalar doesn't document a well-defined withdrawal syndrome. There's no mention of the "electric shocks" of SSRI withdrawal, and ketamine's short half-life (how long the drug stays active in your body) means it's generally out within hours. However, persistent psychiatric events and urinary tract issues may develop after chronic or repeated misuse.

Some users describe lingering cognitive symptoms, emotional flatness, or mood instability if treatments are stopped suddenly after prolonged courses. In rare chronic abusers (not typical in medical depression treatment), bladder and liver issues may persist.

Management Tips:

If you're considering stopping, talk with your doctor about a slow reduction in dosing frequency, especially if you're having side effects.
Track symptoms for at least two weeks after stopping or spacing out infusions.
Persistent symptoms (esp. urinary, cognitive, mood) warrant a reassessment and perhaps an alternative medication.

Timeline: Most acute effects end within hours–days; chronic cognitive or urinary issues (almost always in non-medical or very high/repeated doses) may take weeks or months to resolve.

Dosage by Condition

Condition	Starting Dose	Typical Dose	Maximum Dose
Anesthesia	1–4.5 mg/kg IV/IM	6–10 mg/kg/hr (maintenance infusion)	4.5 mg/kg (IV/IM bolus)
Depression (off-label/SPRAVATO alt.)	0.5 mg/kg IV	0.5–1 mg/kg IV	1 mg/kg IV

For depression, the typical dose used is 0.5 mg/kg IV over 40 minutes, repeated 1–2x/week. Higher doses are not more effective and may increase side effect risk. Always adjust under specialist care.
No dose-response improvement above 1 mg/kg for antidepressant effect; higher doses mainly increase dissociation, cognitive effects, and cardiovascular risks.

Find Top Clinical Trials

Choose from over 30,000 active clinical trials.

Alternatives

When Ketamine's side effects don't work for you, the shortlist includes:

Bupropion (NDRI): Activating, weight-neutral, rarely causes sexual side effects, but can increase anxiety for some
SNRIs (e.g., venlafaxine): Improve energy, can raise BP, sometimes cause sexual dysfunction
MAOIs: "Last resort" option; dietary restrictions but powerful for atypical/tricky depression
Spravato (esketamine): Intranasal; similar rapid-acting mechanism, may have less cognitive impact for some
TMS (transcranial magnetic stimulation): Non-drug, can avoid cognitive and urinary side effects

If you're fighting brain fog and dissociation, options like bupropion, TMS, or emerging clinical trial agents (e.g., CYB003, osavampator) might steer clear.

→ Compare your options on WithPower

Clinical Trials

Looking for something beyond Ketamine? Here are some clinical trials and why they're interesting:

CYB003 (deuterated psilocybin analog): Works via 5-HT2A receptor agonism (serotonin receptor), promising rapid response (1–3 weeks), minimal cognitive/sexual/weight side effects, and remission rates up to 75% at 4 months source.
Osavampator (AMPA-PAM): Allosteric modulator of the AMPA receptor (enhances brain signaling). Early data shows little sedation, no sexual/weight side effects, and fast mood response.
D-cycloserine: NMDA partial agonist; used adjunctively. Minimal chronic side effects, mild/tolerable transient ones.
Classic psilocybin (Phase 3 trials): Fast-acting, no persistent sexual/cognitive/weight issues, but occasional transient anxiety and headache.

Most trials offer extensive monitoring and care (and the thrill of science, for better or worse). Placebo is possible, but many participants say close follow-up was its own form of support. It's early days for most of these drugs—Phase 2 means "promising" but not guaranteed.

Interested in clinical trials? Many trials for depression now target different mechanisms than Antidepressant—potentially offering different side effect profiles. Browse clinical trials →

Decision Map

If brain fog/memory issues are the dealbreaker → try CYB003 (psilocybin analog), osavampator (AMPA-PAM), or D-cycloserine trials

If anxiety or panic is your worst symptom → consider bupropion (if no anxiety disorder), TMS, or clinical trials (CYB003, osavampator) that report lower rates of anxiety

If nausea or dissociation is intolerable → explore alternatives like TMS or bupropion, and see if clinical trials exclude these as common effects

→ Compare trials and alternatives matched to your priorities

Ketalar (ketamine) - antidepressant medication Image: Medical Marketing and Media

Monitoring & What to Track

Your doctor should track:

Mood changes (PHQ-9 or MADRS for depression)
Blood pressure and heart rate before/after each session (esp. if history of hypertension)
Cognitive function (self-report, basic screening)
Urinary symptoms (especially with repeated dosing)
Suicidal ideation—particularly early in treatment

You should track:

Mood day-by-day (1–10 scale)
Side effects: type, severity, timing
Memory/cognitive clarity (especially after repeat sessions)
Blood pressure at home if hypertensive or sensitive

If your doctor isn't tracking these, ask them to. It protects both you and the data.

Pregnancy & Breastfeeding

Pregnancy: No FDA pregnancy category for Ketalar. Animal studies suggest fetal risk at high/abusive doses; controlled studies in humans are lacking. For depression, Ketamine is reserved for those who have failed safer antidepressants in pregnancy.

Risks in pregnancy and breastfeeding:

Risks: Data is limited. In animals, high/repeated doses affect fetal development. Single or rare exposures less studied.
Breastfeeding: Unknown if excreted in human milk; short half-life suggests limited exposure but not well studied.
Untreated depression itself raises pregnancy risks—talk with your provider about all options.
Never stop suddenly if you become pregnant; work with your doctor to taper or switch drugs safely.

Emergency Warning Signs

⚠️ Call 911 or go to ER immediately if you experience:

Suicidal thoughts or plans
Persistent hallucinations, confusion, or delirium lasting more than 12 hours after a session (emergence reactions)
Severe allergic reaction (rash, swelling, difficulty breathing)
Chest pain, sudden drop in consciousness, or fainting during/after session
Difficulty breathing, severe slow or rapid heartbeat

📞 Call your doctor urgently if:

Unusual bleeding or bruising
Severe anxiety or panic attacks that don't resolve after session
Worsening depression
New or worsening urinary symptoms (pain, blood, frequency)

Poison Control: 1-800-222-1222
National Suicide Prevention Lifeline: 988

Summary & Next Steps

Key takeaways: Ketalar (ketamine) brings rapid action but is notorious for dissociation (7/15 users), brain fog (5/15, severe in some), and a real chance of acute anxiety or panic (6/15, moderate). In FDA studies, 12% experienced emergence delirium, and 10% had high blood pressure. These effects usually resolve—but persistent cognitive symptoms are a genuine risk.

If Ketamine is working for you: Keep your sessions scheduled, track for side effects, and report any cognitive or mood changes. Watch for rising blood pressure or urinary issues after repeated use.

If side effects are intolerable: Talk to your provider about dose, interval, or a switch. Consider alternatives like TMS or bupropion, or look into clinical trials for CYB003, osavampator, or D-cycloserine with fewer chronic or cognitive effects.

Your next steps:

Track your symptoms for 2 weeks using a mood diary
Discuss this guide with your doctor at your next appointment
If considering alternatives, → explore clinical trials

→ Find clinical trials matched to your situation

Appendix A: FDA Label Data Summary

Adverse Reactions by Prevalence (Clinical Trial Data)

Side Effect	Drug Rate	Placebo Rate	Category	System
Emergence reactions (post-operative delirium)	12%	0%	very common	Psychiatric
Elevated blood pressure	10%	0%	very common	Cardiovascular
Elevated heart rate (tachycardia)	10%	0%	very common	Cardiovascular
Cardiac arrhythmias ⚠️	0%	0%	unknown	Cardiovascular
Cardiac decompensation ⚠️	0%	0%	unknown	Cardiovascular
Decreased blood pressure (hypotension)	0%	0%	unknown	Cardiovascular
Decreased heart rate (bradycardia)	0%	0%	unknown	Cardiovascular
Diplopia	0%	0%	unknown	Eye
Nystagmus	0%	0%	unknown	Eye
Elevation in intraocular pressure	0%	0%	unknown	Eye
Anorexia	0%	0%	unknown	Gastrointestinal
Nausea	0%	0%	unknown	Gastrointestinal
Vomiting	0%	0%	unknown	Gastrointestinal
Hepatobiliary dysfunction ⚠️	0%	0%	unknown	Gastrointestinal
Local pain at injection site	0%	0%	unknown	Administration site
Exanthema at injection site	0%	0%	unknown	Administration site
Anaphylaxis ⚠️	0%	0%	unknown	Immune system
Enhanced muscle tone and spasms (seizure-like activity)	0%	0%	unknown	Neurologic
Adverse psychiatric events (persistent) ⚠️	0%	0%	unknown	Psychiatric
Dysuria	0%	0%	unknown	Renal and urinary
Increased urinary frequency	0%	0%	unknown	Renal and urinary
Urgency	0%	0%	unknown	Renal and urinary
Urge incontinence	0%	0%	unknown	Renal and urinary
Hematuria	0%	0%	unknown	Renal and urinary
Cystitis (non-infective, interstitial, ulcerative, erosive, hemorrhagic) ⚠️	0%	0%	unknown	Renal and urinary
Ureteric stenosis (strictures) ⚠️	0%	0%	unknown	Renal and urinary
Ureteric obstruction ⚠️	0%	0%	unknown	Renal and urinary
Hydronephrosis ⚠️	0%	0%	unknown	Renal and urinary
Reduced bladder capacity ⚠️	0%	0%	unknown	Renal and urinary
Respiratory depression ⚠️	0%	0%	unknown	Respiratory

Drug Interactions

Theophylline or aminophylline: Do not co-administer; may lower seizure threshold.
Sympathomimetics and vasopressin: May enhance sympathomimetic effects of ketamine; monitor vital signs and consider dose adjustment.
Benzodiazepines, opioid analgesics, or other CNS depressants (including alcohol): May result in profound sedation, respiratory depression, coma, or death. Opioid analgesics may prolong recovery time.

Appendix B: Reddit User-Reported Side Effects

Data extracted from Reddit discussions. Counts show how many posts/comments mentioned each side effect.

Side Effect	Mentions	Severity	Duration	Persists?
Feeling detached from body or surroundings (dissociation)	7 posts	🟢 Mild (5/7)	Typically lasts 30-60 minutes during session, sometimes lingering for a few hours after	Resolves
Nausea and upset stomach	6 posts	🟢 Mild (4/6)	Waves of nausea during or after treatment, sometimes lasting hours	Resolves
Increased anxiety or nervousness	6 posts	🟡 Moderate (2/6)	During or after session, lasting from minutes to a few hours	Resolves
Feeling calm, relaxed, or drowsy (sedation)	5 posts	🟢 Mild (4/5)	Several hours after session, sometimes up to a day	Resolves
Brain fog, memory issues, and slow thinking	5 posts	🟠 Severe (2/5)	Can last for days after infusion, sometimes ongoing with repeated use	⚠️ Yes
Euphoric or happy feeling	4 posts	🟢 Mild (4/4)	During and shortly after session, up to a few hours	Resolves
Dizziness or vertigo	4 posts	🟢 Mild (3/4)	During or shortly after session, resolves within hours	Resolves
Vivid or visual hallucinations	3 posts	🟢 Mild (2/3)	During session, resolves after effects wear off	Resolves
Blurred vision	2 posts	🟢 Mild (2/2)	During session, resolves after effects wear off	Resolves
Headache	2 posts	🟢 Mild (1/2)	During or after session, resolves within hours	Resolves
Episodes of rage or anger	2 posts	🟡 Moderate (1/2)	During session, resolves after effects wear off	Resolves
Panic attacks or intense panic	2 posts	🟡 Moderate (1/2)	During session, resolves after effects wear off	Resolves
Vomiting	2 posts	🟢 Mild (1/2)	During or shortly after session, resolves within hours	Resolves
High blood pressure	2 posts	🟢 Mild (1/2)	During session, resolves after effects wear off	Resolves
Muscle relaxation and calmness	2 posts	🟢 Mild (2/2)	During session, resolves after effects wear off	Resolves

User Quotes by Side Effect

Feeling detached from body or surroundings (dissociation) (Begins within 10-15 minutes of administration, peaks during session, resolves within 1-2 hours after session)

"Ketamine is called a dissociative drug because during a high, which lasts about an hour, people might feel detached from their body, their emotions, or the world around them." source

"After about 10 minutes I felt something happening: my arms and legs felt further away, and my body felt sort of numb, and my brain was mellower." source

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

Nausea and upset stomach (Usually starts during or shortly after session, resolves within a few hours)

"I'm also being hit with waves of nausea, but not throwing up." source

"I was told what I experienced was common K. side effects: terror, panic, rage and crying constantly with vertigo and nausea." source

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

Increased anxiety or nervousness (Can start during session, may peak after session, usually resolves within hours)

"After about an hour I experienced significant anxiety, which lasted for ~4 hours. Not panic attack levels, but levels that I haven't felt in many years." source

"Four doses of oral ketamine have CURED my ADHD, arthritis pain, depression, and anxiety. Suicidal ideation is gone for the first time in 33 years." source

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

Feeling calm, relaxed, or drowsy (sedation) (Begins during session, peaks after, resolves within several hours)

"Depending on the dose and administration, there is certain wonky grogginess that people experience for several hours after the session." source

"You just feel really calm and relaxed." source

"The immediate 'relief' of being calm and able to relax. Seeing life in a positive light." source

Brain fog, memory issues, and slow thinking (Can start during or after session, may persist for days or longer, especially with repeated use)

"Horrible brain fog, zero short term memory, literally feel like a zombie." source

"I'm seriously suffering with what feels like brain damage. My cognition and thoughts are slow and disorganized. I can't drive very often or work anymore." source

"Anyone feeling slightly dumber, slower or fuzzy-headed ..." source

Euphoric or happy feeling (Begins during session, peaks during, fades within a few hours)

"The first time I did it my body felt calm and happy. It was a euphoric feeling." source

"A feeling of optimism, hope, pleasure and passion from what I enjoyed and a return of a positive response to good things like sunshine etc." source

"Maybe 45 minutes to an hour, a glowy feeling afterwards, no urge to use again." source

Dizziness or vertigo (Starts during or after session, resolves within a few hours)

"I was told what I experienced was common K. side effects: terror, panic, rage and crying constantly with vertigo and nausea." source

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

Vivid or visual hallucinations (Begins during session, resolves as drug wears off)

"It can cause vivid hallucinations which of course raise the risk for delirium." source

"I felt like I was seeing the past, present, and future." source

Blurred vision (Starts during session, resolves within hours)

"Eyes are blurry." source

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

Headache (Starts during or after session, resolves within hours)

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

Episodes of rage or anger (During session, resolves after effects wear off)

"I was told what I experienced was common K. side effects: terror, panic, rage and crying constantly with vertigo and nausea." source

Panic attacks or intense panic (During session, resolves after effects wear off)

"I was told what I experienced was common K. side effects: terror, panic, rage and crying constantly with vertigo and nausea." source

Vomiting (During or after session, resolves within hours)

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

High blood pressure (During session, resolves after effects wear off)

"The main side effects are dissociation, intoxication, sedation, high blood pressure, dizziness, headache, blurred vision, anxiety, nausea, and vomiting." source

Muscle relaxation and calmness (During session, resolves after effects wear off)

"It instantly calms all my muscles and let's me relax for much needed ..." source

"My body felt calm and happy." source

Appendix C: Clinical Trials with Different Mechanisms

These trials target mechanisms different from Antidepressant. Phase 2 results do not guarantee Phase 3 success.

CYB003 (deuterated psilocybin analog)

Sponsor: Cybin Inc.
Phase: Phase 2 (Breakthrough Therapy Designation, Phase 3 planned)
NCT: NCT05385783
Mechanism: Deuterated psilocybin analog (psychedelic-derived, 5-HT2A receptor agonist)
Side Effect Comparison: Transient mild-moderate headache (20%), nausea (15%), and anxiety (10%) during dosing session; no sexual dysfunction, weight gain, or chronic sedation as seen with SSRIs/SNRIs. No evidence of withdrawal or dependence.
Efficacy Data:
- Response rate: 79% at 3 weeks (CYB003 16mg)
- Remission rate: 75% at 4 months (Phase 2, CYB003)
- MADRS change: -14.08 points (CYB003 16mg) vs -8.24 (placebo) at 3 weeks
- Time to response: 1-3 weeks
- Source
Why it might interest you: Rapid onset (1-3 weeks), single or few doses, minimal chronic side effects, no sexual dysfunction or weight gain, novel mechanism for those not responding or intolerant to standard antidepressants.
Results: Rapid and robust reduction in depressive symptoms, high remission and response rates, durable effect at 4 months post-dose.
Sources: 1, 2, 3

Osavampator (NBI-1065845, TAK-653)

Sponsor: Neurocrine Biosciences
Phase: Phase 3 (recruiting)
Mechanism: AMPA receptor positive allosteric modulator (AMPA-PAM)
Side Effect Comparison: Phase 2: No significant increase in weight gain, sexual dysfunction, or sedation compared to placebo. Side effect profile appears favorable vs SSRIs/SNRIs, with low rates of common antidepressant side effects.
Efficacy Data:
- Response rate: Not yet reported (Phase 3 ongoing)
- Remission rate: Not yet reported (Phase 3 ongoing)
- MADRS change: Not yet reported (Phase 3 ongoing); Phase 2 showed significant improvement vs placebo
- Time to response: Expected to be faster than SSRIs (based on AMPA mechanism)
- Source
Why it might interest you: Novel mechanism (AMPA modulation) may offer faster onset and fewer side effects (less sexual dysfunction, weight gain, sedation) than standard antidepressants. Suitable for those with side effect burden or inadequate response to SSRIs/SNRIs.
Results: Phase 2 data showed significant improvement in depressive symptoms as adjunctive therapy; Phase 3 underway to confirm efficacy and safety.
Sources: 1, 2, 3

D-cycloserine (adjunctive)

Sponsor: Academic/NIH
Phase: Phase 2 (completed)
NCT: NCT00408031
Mechanism: NMDA receptor partial agonist (glycine site)
Side Effect Comparison: No significant increase in sedation, weight gain, or sexual dysfunction compared to placebo. Side effect profile generally mild and transient, unlike SSRIs/SNRIs.
Efficacy Data:
- Response rate: Not reported
- Remission rate: Not reported
- MADRS change: -7.6 points vs -3.1 placebo (D-cycloserine adjunct, 6 weeks, TRD)
- Time to response: 2-6 weeks
- Source
Why it might interest you: Different mechanism (NMDA modulation), adjunctive use, minimal side effects, no sexual dysfunction or weight gain, may help those with inadequate response or intolerable side effects from standard antidepressants.
Results: Significant reduction in depressive symptoms as adjunct to antidepressants in treatment-resistant depression.
Sources: 1

Psilocybin (various trials, e.g., COMPASS Pathways)

Sponsor: COMPASS Pathways, Usona, others
Phase: Phase 3 (recruiting)
NCT: NCT06141876
Mechanism: Classic psilocybin (5-HT2A receptor agonist, psychedelic)
Side Effect Comparison: Transient anxiety, headache, and nausea during dosing; no chronic sexual dysfunction, weight gain, or sedation. No evidence of dependence or withdrawal.
Why it might interest you: Single/few doses, rapid onset, minimal chronic side effects, no sexual dysfunction or weight gain, novel mechanism for those with side effects or poor response to standard antidepressants.
Results: Multiple studies show rapid, robust, and durable antidepressant effects after 1-2 doses in MDD and TRD.
Sources: 1, 2

Appendix D: Methodology

This guide was developed by analyzing more than 30,000 clinical trial records from ClinicalTrials.gov, synthesizing data from over 300 peer-reviewed journal articles via PubMed, and examining 54 user discussions across the web. The OpenFDA Drug Label database provided detailed adverse effect profiles. Reviewers prioritized 15 user-reported side effects, categorizing them by frequency, severity, and chronicity, and included authentic patient experiences with precise sourcing.