How Should I Prepare for IV Therapy?
Written by YiQiu Hu, NMD
Arizona-licensed naturopathic physician and virtual concierge medicine provider
Published August 2026 | Medically reviewed August 2026
Preparing for IV therapy is usually straightforward. In most cases, the most important steps are to follow the instructions provided by your physician, arrive normally hydrated, eat normally unless you have been told to fast, bring an accurate medication and supplement list, and tell your clinician about any recent changes in your health.
You generally should not stop prescription medications, intentionally fast, or dramatically increase your water intake simply because you are receiving an IV unless your healthcare professional specifically recommends it.
The exact preparation depends on your health history and what is being administered.
If you would like a more detailed preparation checklist, read our Patient’s Guide to Preparing for an IV Therapy Appointment.
1. Follow the Instructions for Your Specific IV
There is no single preparation protocol that applies to every IV infusion.
A hydration-only infusion may require different considerations from an infusion containing electrolytes, magnesium, vitamin C, B vitamins, glutathione, or other ingredients.
Your physician may also modify your instructions based on factors such as:
Your medical history
Kidney function
Cardiovascular health
Blood pressure
Blood glucose
Medications
Pregnancy
Previous reactions to IV treatments
Fluid restrictions
The ingredients and doses being considered
For that reason, instructions from the clinician responsible for your treatment should take priority over generalized advice found online.
At Ask Dr. Hu, IV therapy is individualized based on the patient rather than selected solely from a predetermined infusion menu.
2. Should You Drink Water Before IV Therapy?
For many otherwise healthy patients, maintaining normal hydration before an IV appointment is reasonable.
Being substantially dehydrated may make peripheral veins harder to access. Hydration can sometimes make veins more prominent and easier to identify for peripheral IV placement.
However, more water is not automatically better.
If you have:
Kidney disease
Heart failure
Significant swelling or edema
A medical condition affecting fluid balance
A prescribed fluid restriction
do not intentionally increase your water intake without discussing it with your healthcare professional.
Your normal fluid recommendations should take priority over trying to make IV placement easier.
For additional information, see IV Hydration Therapy: Potential Benefits and Medical Considerations.
3. Should You Eat Before IV Therapy?
Most routine elective IV nutrient or hydration appointments do not automatically require fasting.
Unless your physician has instructed you otherwise, following your normal eating pattern before your appointment is generally reasonable.
Some people feel more comfortable when they have eaten rather than arriving hungry, particularly if they are prone to lightheadedness or fluctuations in blood glucose.
However, you may receive different instructions if:
Fasting laboratory testing is being performed
Another procedure is scheduled
You have diabetes or hypoglycemia
You take glucose-lowering medications
Your specific treatment requires different preparation
Do not assume that fasting makes IV therapy more effective.
If fasting is necessary for laboratory testing or another reason, your healthcare professional should tell you beforehand.
4. Do Not Stop Medications on Your Own
Bring an accurate list of your current medications to your appointment.
This should include:
Prescription medications
Over-the-counter medications
Injectable medications
Hormone therapy
Weight-loss medications
Blood pressure medications
Diabetes medications
Diuretics
Anticoagulants or antiplatelet medications
Medications prescribed by specialists
Whenever possible, include the medication name, dose, and how frequently you take it.
Do not stop a prescribed medication simply because you are receiving IV therapy unless the healthcare professional managing your treatment specifically instructs you to do so.
Some medications can influence kidney function, electrolytes, blood pressure, blood glucose, bleeding, or fluid balance, which is why an accurate medication review is important before an infusion.
5. Tell Your Physician About Vitamins and Supplements
Supplements should also be included in your medication review.
Tell your physician about any:
Vitamins
Minerals
Multivitamins
Herbal products
Electrolytes
Amino acids
Nutritional powders
Injectable vitamins
Compounded products
Other IV treatments
This is particularly important when your planned IV contains nutrients that you are already receiving from another source.
An IV formulation should be selected based on your individual circumstances rather than simply combining as many vitamins or nutrients as possible.
You can learn more about this process in our IV Therapy Resources for Arizona Patients.
6. Bring Relevant Laboratory Results
You do not necessarily need laboratory testing before every IV infusion.
However, laboratory testing may sometimes be useful depending on your medical history and the ingredients being considered.
Testing could potentially include kidney function, electrolytes, blood counts, glucose, nutrient levels, iron studies, liver function, or ingredient-specific testing.
For example, higher-dose intravenous vitamin C requires additional consideration in people with kidney disease, kidney-stone risk, G6PD deficiency, or iron overload conditions such as hemochromatosis. The National Cancer Institute specifically identifies these as important safety considerations with high-dose IV vitamin C.
If you already have recent laboratory results, making them available to your physician may prevent unnecessary duplication.
Read Laboratory Testing Before IV Therapy: When Is It Needed? for a more detailed explanation.
7. Tell Your Physician If Anything Has Changed
Even if you have received IV therapy before, your physician should know about important changes in your health.
Before your appointment, mention any new:
Fever or illness
Vomiting or diarrhea
Shortness of breath
Swelling
Chest symptoms
Changes in urination
Kidney problems
Medications
Supplements
Allergies
Abnormal laboratory results
Pregnancy
Hospitalization
Diagnoses
Reactions to a previous infusion
A formulation that was appropriate previously is not necessarily appropriate under different medical circumstances.
If you are uncertain whether a new symptom affects your appointment, contact your healthcare professional before treatment.
8. Tell the Clinician About Previous IV Problems
If your veins have been difficult to access in the past, mention it before IV placement.
It can be helpful to tell your clinician if:
One arm usually works better than the other
You frequently require multiple IV attempts
You have had an infiltration or phlebitis
You have a dialysis fistula or other vascular access
You have had lymph-node surgery or have been told not to use a particular arm
You previously experienced a reaction during an infusion
A peripheral IV consists of a small flexible catheter placed into a vein, usually in the hand or arm.
Sharing your previous experience can help your clinician plan the most appropriate access site.
9. Wear Comfortable Clothing
Wear clothing that makes your arm easy to access.
A short-sleeved shirt or loose sleeves that can comfortably roll above the elbow usually work well.
Avoid sleeves that become very tight around the upper arm when rolled up.
If you tend to feel cold while sitting, bringing a light sweater, jacket, or blanket may also make the appointment more comfortable.
10. Give Yourself Enough Time
An IV appointment may involve more than the infusion itself.
Depending on the visit, time may be needed for:
Medical history review
Vital signs
Medication and supplement review
Laboratory review
Confirmation of the IV formulation
IV preparation
Catheter placement
The infusion
Monitoring
IV removal
Post-treatment instructions
Infusion duration varies depending on the solution, ingredients, dosage, fluid volume, prescribed rate, and individual response.
You can read more about the process in A Patient’s Guide to What Happens During an IV Infusion.
What Should I Bring to My IV Therapy Appointment?
For a first appointment in particular, consider having the following information available:
Current medication list
Current vitamin and supplement list
Known allergies
Significant medical conditions
Recent laboratory results, if available
Information about previous IV reactions
Information about difficult venous access
Questions you would like to discuss
You do not need to arrive knowing exactly which IV formulation you want.
Determining whether IV therapy is appropriate—and which ingredients, fluid volume, dosage, and infusion rate make sense—is part of the medical decision-making process.
What Should I Avoid Before IV Therapy?
Unless your physician has given you specific restrictions, preparation does not usually require an extensive list of things to avoid.
The most important things not to do on your own are:
Do not stop prescription medications without medical guidance.
Do not intentionally fast unless instructed.
Do not dramatically increase fluid intake if you have a fluid restriction or condition affecting fluid balance.
Do not hide medications, supplements, allergies, or medical conditions from your clinician.
Do not assume a previous IV formulation remains appropriate if your health has changed.
Do not receive an elective IV when concerning new symptoms require another form of medical evaluation first.
IV therapy should be approached as a medical treatment rather than simply a wellness product.
What If I Am Nervous About the IV?
It is normal to have questions about IV placement, particularly if you have never received an infusion before.
A peripheral IV is typically placed using a needle to enter the vein. Once the catheter is positioned, the needle is removed and the small flexible catheter remains during the infusion.
Tell your clinician if you are particularly anxious, have fainted with needles in the past, or have experienced difficult IV placement.
During the infusion, promptly report increasing pain, burning, swelling, redness, leaking, or significant tenderness around the IV site. Peripheral IV sites should be evaluated when symptoms suggest phlebitis, infection, or catheter malfunction.
The Most Important Preparation Happens Before the IV Is Started
Preparing for IV therapy is not primarily about drinking a certain amount of water or following a special diet.
The most important preparation is making sure your healthcare professional has enough information to determine whether the treatment is appropriate for you.
That includes your medical history, medications, supplements, allergies, recent health changes, laboratory findings when relevant, and the reason you are considering treatment.
At Ask Dr. Hu, IV therapy begins with individualized medical evaluation and treatment selection rather than a one-size-fits-all infusion.
If you are considering treatment, explore our IV Therapy services or our complete collection of IV Therapy Resources.
Frequently Asked Questions About Preparing for IV Therapy
Should I drink a lot of water before IV therapy?
Not necessarily. For many patients, normal hydration is appropriate and may make peripheral venous access easier. However, patients with kidney disease, heart conditions, edema, or fluid restrictions should follow individualized recommendations rather than deliberately drinking large amounts of water.
Should I eat before an IV infusion?
Unless you have specifically been instructed to fast, most routine elective IV nutrient or hydration appointments do not require fasting. Follow the instructions provided for your particular appointment.
Can I take my normal medications before IV therapy?
In general, do not stop prescribed medications unless your healthcare professional specifically tells you to do so. Bring an accurate medication list so potential treatment considerations can be reviewed.
Do I need blood work before IV therapy?
Not everyone does. Whether laboratory testing is appropriate depends on your medical history, symptoms, and the ingredients and doses being considered. Read more about laboratory testing before IV therapy.
What should I wear to an IV appointment?
Comfortable clothing with easy access to your arm is ideal. Short sleeves or loose sleeves that can roll comfortably above the elbow usually make IV placement and monitoring easier.
What happens after the infusion?
Post-treatment recommendations depend on the formulation and how you respond. Our IV Therapy Aftercare and Monitoring Guide explains IV-site care, monitoring, and symptoms that should be reported.
How This Article Was Developed
This article was written and medically reviewed to provide practical, medically responsible guidance for patients preparing for intravenous therapy.
The recommendations reflect established principles of patient screening, medication and medical-history review, peripheral IV safety, ingredient-specific precautions, hydration and fluid-balance considerations, and appropriate clinical monitoring.
Medical and safety information was reviewed alongside resources from organizations including:
Medical information can change as clinical evidence, safety recommendations, medications, and treatment practices evolve. This page should be reviewed periodically and updated when appropriate.
This information is intended for general education and does not replace individualized medical advice or establish a physician-patient relationship.
About the Author
YiQiu Hu, NMD is an Arizona-licensed naturopathic physician and founder of Ask Dr. Hu. He provides concierge medicine, preventive healthcare, health optimization, laboratory evaluation, IV therapy, and individualized medical care for patients throughout Arizona.
Dr. Hu’s approach emphasizes careful medical evaluation, clear patient education, evidence-informed treatment selection, and appropriate consideration of both the potential benefits and limitations of medical and naturopathic therapies.
Learn more about Dr. Hu and the Ask Dr. Hu medical team, explore IV Therapy services, or contact Ask Dr. Hu with questions about becoming a patient.