Can You Eat Before a Ketamine Session? Fasting and Diet Guidelines

The General Rule: Keep It Light — or Skip It

One of the most practical questions patients have before a ketamine session is whether they should eat beforehand. The answer is important because it directly affects how comfortable your session will be — specifically, whether you experience nausea, which is one of the most common side effects of ketamine therapy.

The general recommendation from most providers is to avoid eating for at least four to six hours before your session, and to avoid drinking liquids for about one to two hours before. Some providers have slightly different guidelines depending on the route of administration, so always follow your specific provider's instructions. But here is a detailed look at why fasting matters and how to handle nutrition around your treatment.

Why Fasting Helps

Reducing Nausea

Nausea occurs in roughly 10 to 30 percent of ketamine patients, and having food in your stomach significantly increases the risk. Ketamine can slow gastric motility (the speed at which your stomach processes food) and can trigger the brain's nausea center. When your stomach is empty, there is simply less material to cause problems.

Patients who fast before their sessions consistently report lower rates and milder severity of nausea compared to those who eat close to treatment time.

Preventing Aspiration Risk

While rare in sub-anesthetic ketamine therapy, there is a small theoretical risk of aspiration (inhaling stomach contents) if nausea leads to vomiting during a dissociative state. This is the same reason surgeons require fasting before procedures involving sedation or anesthesia. Learn more about ketamine's full side effects profile. Having an empty stomach minimizes this risk.

Improving the Experience

Beyond nausea prevention, many patients report that fasting leads to a cleaner, more comfortable experience overall. Without the distraction of digestive activity, you may be able to settle into the session more easily.

Fasting Guidelines by Route of Administration

IV Infusion

• Food: Do not eat for 4-6 hours before your appointment
• Clear liquids: You may sip water up to 1-2 hours before
• Medications: Take your regular medications with a small sip of water unless your provider instructs otherwise

Spravato (Nasal Spray)

• Food: Do not eat for at least 2 hours before your appointment
• Liquids: Do not drink for at least 30 minutes before
• Nasal preparations: Do not use nasal decongestants or nasal corticosteroids for at least 1 hour before

Sublingual (Oral) Ketamine

• Food: Do not eat for 2-4 hours before your session
• Liquids: Small sips of water are generally fine up to 1 hour before
• Important note: The medication needs to absorb through the tissue under your tongue. Having food residue in your mouth can interfere with absorption.

What to Eat the Day Before and Earlier in the Day

While you should not eat close to your session, what you eat earlier in the day (or the night before) does matter:

Good Choices

• Light, easily digestible foods — Rice, toast, bananas, plain chicken, soup, oatmeal. These foods are gentle on the stomach and will not leave you feeling heavy.
• Small portions — Eat enough to sustain your energy, but do not overeat.
• Balanced meals — Include some protein and complex carbohydrates for sustained energy, rather than simple sugars that cause spikes and crashes.

Foods to Avoid

• Heavy, greasy, or fried foods — These take longer to digest and increase nausea risk even hours later.
• Spicy foods — These can irritate the stomach and worsen nausea if any remains in your system.
• Large meals — A big meal the night before or morning of your session can still be partially in your stomach hours later.
• High-fiber foods in excess — While fiber is generally healthy, large amounts can slow digestion and increase bloating.
• Dairy — For some people, dairy can contribute to nausea and stomach discomfort. If you know dairy affects your stomach, avoid it before treatment.

Staying Hydrated

Hydration is important, both for your overall well-being and for the practical aspects of treatment (if you are receiving an IV infusion, being well-hydrated makes it easier to place the IV line).

• Drink plenty of water in the hours and day before your session
• Stop drinking about one to two hours before your appointment (for IV and sublingual; 30 minutes for Spravato)
• Avoid caffeine on treatment days, as it can increase anxiety and potentially interact with ketamine's cardiovascular effects
• Avoid alcohol for at least 24 hours before your session

What About Medications?

Take your regular prescribed medications as usual unless your provider specifically tells you to skip or adjust something. When in doubt, ask. Here are some specific considerations:

• Anti-nausea medication — Your provider may prescribe ondansetron (Zofran) or a similar medication to take 30 to 60 minutes before your session. This can dramatically reduce nausea risk and is taken with a small sip of water.
• Blood pressure medication — Continue taking this as prescribed. Ketamine can elevate blood pressure, and your regular medication helps manage this.
• Benzodiazepines — Some research suggests that benzodiazepines may reduce the effectiveness of ketamine. Discuss this with your provider, as they may recommend adjusting the timing.
• Supplements — Follow your provider's guidance on any supplements you take. Some, like certain herbal preparations, may need to be paused.

After Your Session: What and When to Eat

Once your session is complete and you are feeling stable, eating a light meal or snack can help you recover:

• Start light — Crackers, toast, broth, or fruit are gentle choices for the first meal after treatment.
• Listen to your body — Some patients feel hungry fairly quickly after a session, while others do not have an appetite for a few hours. There is no rush.
• Stay hydrated — Continue drinking water throughout the rest of the day.
• Avoid alcohol — Do not drink alcohol for the remainder of the day after treatment.

If your session was in the morning and you fasted beforehand, having a nourishing lunch or dinner afterward is a good idea to replenish your energy.

What If You Accidentally Eat Too Close to Your Session?

If you ate something within the fasting window, let your provider know before your session. They may:

• Delay the session slightly to allow more digestion time
• Pre-treat you with anti-nausea medication
• Adjust the infusion rate (for IV sessions) to reduce nausea risk
• Proceed with the session but with extra monitoring for nausea

Do not hide this information from your provider. They would much rather know and adjust accordingly than deal with preventable nausea during your treatment.

The Bigger Picture

Fasting before ketamine therapy is a small but meaningful part of preparing for a good session. Think of it as one element of your overall preparation routine — alongside arranging transportation, setting up a comfortable environment, and coming to the session with an open mind.

Your provider's specific guidelines take priority over general advice, so always check with them about their exact fasting requirements. When in doubt, err on the side of a longer fast and a lighter previous meal. Your comfort during the session is worth the temporary inconvenience of skipping a meal.

References

• MedlinePlus: Ketamine Injection — National Library of Medicine drug information on ketamine, including preparation guidelines
• Mayo Clinic: Ketamine (Injection Route) — Mayo Clinic information on ketamine precautions and side effects including nausea