IV therapy is generally considered safe when administered by qualified medical professionals using sterile equipment and appropriate protocols. Millions of IV infusions are performed every year in both clinical and wellness settings without incident. However, like any medical procedure that involves inserting a needle into a vein, IV therapy does carry risks and potential side effects that you should understand before booking a session.
This guide covers the full spectrum of possible side effects — from common and minor to rare and serious — so you can make a fully informed decision.
Common and Minor Side Effects
These side effects occur in a meaningful percentage of IV therapy sessions and are generally not cause for concern. They typically resolve on their own within minutes to hours.
Bruising at the Injection Site
Small bruises around the IV insertion point are the most common side effect. They occur when the needle nicks a small blood vessel during insertion or removal. Bruising is more common in people with thin skin, those taking blood thinners, or when the provider needs multiple attempts to find a vein. The bruise typically fades within a few days to a week.
Discomfort or Soreness
Some people experience mild soreness, a feeling of pressure, or a cool sensation in the arm during the infusion. This is usually caused by the temperature of the IV fluid or the rate at which it is being delivered. Let your provider know if you feel discomfort — they can adjust the drip rate or warm the fluid to improve comfort.
A Metallic Taste
Certain IV nutrients, particularly magnesium and some B vitamins, can cause a temporary metallic or mineral taste in your mouth during the infusion. This is harmless and fades once the infusion is complete.
Lightheadedness or Warmth
Some people feel briefly lightheaded, warm, or flushed during certain infusions. This is most common with IV magnesium, which causes blood vessels to dilate. The sensation usually passes within a few minutes. If it persists, the drip rate can be slowed.
Mild Nausea
A small number of people experience mild nausea during or shortly after infusions, especially with higher-dose treatments like NAD+ therapy. Eating a light snack before your session and staying well-hydrated can help reduce this.
Less Common Side Effects
These side effects happen less frequently but are important to be aware of:
Vein Irritation (Phlebitis)
Phlebitis is inflammation of the vein at or near the insertion site. Symptoms include redness, swelling, warmth, and tenderness along the vein. It is more likely with certain nutrients that are irritating to vein walls, particularly at higher concentrations. A warm compress and over-the-counter anti-inflammatory medication usually resolve mild phlebitis within a few days. If symptoms worsen or persist, contact your healthcare provider.
Infiltration
This occurs when the IV fluid leaks out of the vein into the surrounding tissue, causing swelling, tightness, and discomfort near the injection site. A skilled provider will monitor for this during your infusion and reposition the IV if needed. If infiltration occurs, the area typically returns to normal within a few hours as the fluid is absorbed.
Headache
Some people develop a headache during or after certain IV treatments. This can be related to the speed of the infusion, the specific nutrient combination, or a response to rapid changes in hydration status. Slowing the drip rate and ensuring adequate hydration before the session can help prevent this.
Rare but Serious Risks
Serious complications from IV therapy in a wellness setting are uncommon, but they do exist. Understanding these risks is part of making an informed decision.
Infection
Any time a needle breaks the skin, there is a risk of infection. In professional IV therapy settings using proper sterile technique, this risk is very low. Signs of infection include increasing redness, swelling, warmth, pain at the site, or fever in the days following treatment. If you notice these symptoms, seek medical attention promptly.
Air Embolism
An air embolism occurs when air enters the vein through the IV line. This is extremely rare with modern IV equipment, which includes safeguards to prevent air from entering the tubing. Trained professionals are also taught to prime IV lines to remove all air before connecting them. While a small amount of air is generally harmless, large volumes can be dangerous.
Electrolyte Imbalance
Receiving high doses of certain minerals — particularly potassium, magnesium, or calcium — can theoretically shift your electrolyte balance. This is most relevant for people with kidney disease or heart conditions, whose bodies may not regulate these minerals normally. Reputable providers will ask about your medical history and may require blood work before administering certain formulations.
Allergic Reactions
While rare, allergic reactions to IV nutrients or additives can occur. Symptoms range from mild (hives, itching, rash) to severe (difficulty breathing, swelling of the face or throat). Qualified providers should have emergency medications available and be trained to recognize and respond to allergic reactions immediately.
Fluid Overload
Receiving too much IV fluid too quickly can strain the cardiovascular system, particularly in people with heart failure or kidney disease. This is why reputable providers assess your medical history before treatment and monitor you throughout the session. Healthy adults with normal heart and kidney function are at very low risk.
Who Should Be Extra Cautious
Certain groups should consult their physician before receiving IV therapy or may need modified protocols:
- People with kidney disease — The kidneys regulate fluid balance and mineral excretion. Impaired kidney function changes how your body handles IV fluids and nutrients.
- People with heart failure — Extra fluid volume can worsen heart failure symptoms. IV therapy may need to be administered more slowly and in smaller volumes.
- Pregnant or breastfeeding women — Not all IV formulations are appropriate during pregnancy. Read our guide on IV therapy during pregnancy for more detail on what is and is not considered safe.
- People on blood thinners — Higher risk of bruising at the injection site and potential interactions with certain IV nutrients.
- People with allergies to specific vitamins or preservatives — Always disclose all known allergies before treatment.
How to Minimize Your Risk
The most important thing you can do to reduce side effects is choose a reputable provider. Here are specific steps:
- Verify credentials — Ensure the person administering your IV is a licensed medical professional (RN, NP, PA, or paramedic) and that the practice operates under a physician medical director. Our guide to choosing a provider covers what to look for.
- Disclose your full medical history — Do not skip the health intake form. Include all medications, supplements, allergies, and medical conditions.
- Eat before your session — Having food in your stomach reduces the chance of nausea and lightheadedness.
- Stay hydrated — Ironically, being well-hydrated before your IV session makes the process smoother. Hydrated veins are easier to access, reducing the chance of bruising and multiple insertion attempts.
- Speak up during the session — If you feel anything unusual — pain, burning, tightness, dizziness, or nausea — tell your provider immediately. Most side effects can be managed by adjusting the drip rate or stopping the infusion.
If you are ready to find a provider who prioritizes safety and professionalism, search our directory to compare options in your area.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare professional before starting any IV therapy treatment.