Iontophoresis: delivering active ingredients directly to the painful area
Have you ever wondered what happens when you take a medicine? How much of a tablet or capsule remains “untouched” by your digestion? How much is absorbed in the intestinal villi and reaches your bloodstream? And ultimately, how much gets to exactly the place where it is needed? In some cases — for example when treating sports injuries or joint problems — it can be advantageous to deliver the active ingredient directly to the area of complaint. Iontophoresis is such a method. It bypasses digestion and “carries” the active ingredient directly to where it is needed. Get acquainted with the method!
Iontophoresis – where does the name come from?
Using direct current, a dissolved active ingredient can be delivered through the skin into your body by the movement of the ions in the solution under the influence of the electric current – hence the terms “ion migration” and “iontophoresis”.
In solution, active substances dissociate into positively and negatively charged ions, that is, electrically charged particles. Positively charged ones are called cations, negatively charged ones are called anions.
Iontophoresis is based on the principle that under direct current these ions begin to migrate toward the pole opposite to their own charge: a positively charged ion moves toward the negative electrode, and a negatively charged ion toward the positive electrode.
How does iontophoresis work?
Iontophoresis treatment has both local and systemic effects.¹ The active ingredient accumulates at the site of application, forming a so‑called depot, which allows a concentrated and long‑lasting effect. In addition, the locally applied preparation can enter the skin capillaries and from there the bloodstream. Alongside a strong local effect it may also have a weaker systemic effect.
Possible benefits of the treatment include:
Avoiding the digestive tract. This avoids oral administration of preparations, so part of the active ingredient is not broken down in the digestive tract and a larger proportion can act where it is needed.
Targeted delivery of active ingredients. It can deliver the active ingredient directly to the painful area, which can reduce the risk of systemic side effects.²
Circulation‑enhancing effect. Effects induced by direct current can also increase local blood circulation, which may support tissue regeneration.
What can iontophoresis be used for?
Research suggests iontophoresis can help reduce pain, decrease inflammatory symptoms, cause vasodilation, relieve muscle spasm (cramps, stiffness) and soften tissues.³⁻⁴ For these reasons the treatment is often used for:
- treating sports injuries (tendinitis, strains)
- joint pain (knee, elbow, shoulder)
- myofascial pain syndrome⁵
- enhancing the effect of cosmetic preparations
Clinical trials have shown that iontophoresis can help treat tennis elbow (lateral epicondylitis), with reported decreases in pain and improvements in function.⁶
Before you start treatment
For safe use it is important to know the contraindications. If any of the conditions below apply to you, consult your physician before using the device.
When NOT to use it?
Do NOT use an iontophoresis device if you have:
- An implanted pacemaker or defibrillator
- An implanted electronic device (e.g. insulin pump)
- A history of epilepsy or seizure disorders
- Pregnancy (especially over the abdomen and lower back)
- Active thrombosis or thrombophlebitis
- An open wound, skin lesion or infected skin on the treatment area
- A malignant tumor in the area to be treated
- An allergy to the product you intend to use
- A metal implant located directly in the treatment area
Use with caution
Seek medical advice if you have:
- Heart disease
- Diabetes
- Reduced sensation in the treated area (neuropathy)
- Skin disease (e.g. eczema, psoriasis at the treatment site)
Important: Iontophoresis is intended as an adjunct to medical treatment, not as a replacement. Consult your doctor first if you have complaints!
Possible side effects
With correct use the device is generally well tolerated, but the following may occur:
Common, transient reactions:
- Mild redness at the treated area (this is natural because the current causes increased blood flow – it usually subsides within minutes)
- Mild stinging or tingling sensation during treatment
Less common reactions:
- Skin irritation under the electrodes
- Allergic reaction to the preparation used
- Minor burns (with excessively high current)
If redness persists for a long time or you have any lasting symptoms, consult your doctor — it may be a sign of an allergic reaction.
The iontophoresis treatment procedure
Preparation
Before starting the treatment moisten the electrodes. The preparation to be used may have positive, negative or dual polarity:
- Positively polarized active ingredients should be placed on the electrode connected to the positive pole
- Negatively polarized ingredients on the electrode connected to the negative pole
- Dual‑polarity ingredients can be applied to either electrode pole
Electrode placement
Place the electrode soaked with the active ingredient over the painful area, and the other electrode on the opposite side of the area (e.g. right and left of the knee).
Commonly used preparations
Can be delivered from the positive electrode — examples include lidocaine, procaine, calcium chloratum, histamine, tolazoline and vitamin B1.
Can be delivered from the negative electrode — examples include sodium salicylate, potassium iodide, phenylbutazone ointment, Voltaren emulgel, diclofenac gel, Flector gel and Fastum gel.
My advice: Before using any preparation with iontophoresis, make sure you are not allergic to it! Test on a small area the first time.
During the treatment
During treatment set the intensity to a level that produces a pleasant “tickling” feeling in the treated area. Excessive current can be painful and cause skin burns, while too low current will be ineffective.
The amount of active ingredient delivered depends on several factors:
- Duration of current application – adjustable during treatment
- Current strength – depends on your tolerance
- Surface area of the electrode
- Mobility of the ions – determined by the molecular weight of the substance
Treatment protocol
Perform iontophoresis daily; a typical course is 10–15 sessions (in more severe cases up to 20). Start treatments with a low‑frequency iontophoresis program — although lower frequencies have lower delivery capacity, they cause milder skin redness.
Different treatment modes
Unipolar treatment: The active solution is delivered from only one pole. It is important to know which pole a given preparation can be delivered from — if you place it on the wrong pole, the active ingredient will remain in place and will not migrate, rendering the treatment ineffective.
Bipolar treatment: You can deliver active solutions from both poles (positive and negative) simultaneously.
Descending treatment: The active pole is placed above the painful area and the other pole below it (the current direction is descending).
Transverse current direction: Most commonly used for joint treatments and in bipolar treatments.
What do studies show?
Scientific research suggests iontophoresis can be an effective method for transdermal drug delivery.¹ The advantage of the method is that it enables targeted delivery of active ingredients while minimizing systemic side effects.²
In a 2019 randomized, double‑blind clinical trial for lateral epicondylitis (tennis elbow), the iontophoresis group showed significant improvements in pain, strength and function.⁶
For myofascial pain syndrome, lidocaine iontophoresis proved effective in treating trigger points with minimal side effects.⁵
Recommended devices
If you want to perform iontophoresis at home, the IontoBravo iontophoresis device can be a suitable choice. The device operates in both continuous and pulsed modes.
If you would like to perform more complex electrotherapy treatments as well, check out the Globus Genesy SII, the Globus Genesy 600 or the Globus Genesy 3000 devices, which also include iontophoresis programs.
Summary – Quick overview
What is this article? A comprehensive guide to iontophoresis, presenting how this method of delivering active ingredients works, its applications, treatment procedure and safety considerations.
Who is it for?
- People with joint pain
- Those recovering from sports injuries
- People with tendinitis
- Those suffering from myofascial pain syndrome
- Anyone interested in physiotherapy
Main message: Iontophoresis is a non‑invasive method that uses electric current to deliver active ingredients through the skin directly to the painful area. The method can help relieve pain and reduce inflammatory symptoms while minimizing systemic side effects. Iontophoresis is an adjunct to medical treatment — consult your doctor first if you have complaints!
Therapeutic options:
| Therapy | What it's good for | Treatment time | Usable at home? |
|---|---|---|---|
| Iontophoresis | Targeted delivery of active ingredients | 15–20 minutes | Yes |
| TENS | Pain relief | 20–30 minutes | Yes |
| EMS | Muscle strengthening | 15–20 minutes | Yes |
| Ultrasond | Treatment of deeper tissues | 5–10 minutes | Yes |
Frequently asked questions:
How often can I use the iontophoresis device? Once daily; a course typically consists of 10–15 treatments. The interval between treatments and the length of the course depend on the severity of the complaint.
Is the treatment painful? No — with correct settings it causes a pleasant “tickling” sensation. If you feel pain, reduce the current!
When can I expect results? Many people notice relief after a few sessions, but lasting results usually require 2–3 weeks of regular treatment.
Can I use it alongside medications? Yes, iontophoresis can be safely used with pharmacological therapy. Consult your doctor for the exact protocol!
How does it differ from TENS? TENS is used for pain relief by stimulating nerves, while iontophoresis is for targeted delivery of active ingredients. Their goals differ, but many devices include both functions.
Sources
- Wang Y, Zeng L, Song W, Liu J. (2022). Influencing factors and drug application of iontophoresis in transdermal drug delivery: an overview of recent progress. Drug Deliv Transl Res, 12(1):15-26. PubMed: 33486687
- Kalia YN, Naik A, Garrison J, Guy RH. (2004). Iontophoretic drug delivery. Adv Drug Deliv Rev, 56(5):619-58. PubMed: 15019750
- Semalty A, Semalty M, Singh R, Saraf SK, Saraf S. (2007). Iontophoretic drug delivery system: a review. Technol Health Care, 15(4):237-45. PubMed: 17673833
- Dixit N, Bali V, Baboota S, Ahuja A, Ali J. (2007). Iontophoresis - an approach for controlled drug delivery: a review. Curr Drug Deliv, 4(1):1-10. PubMed: 17269912
- Kaya A, Güçlü B, Çolakoğlu Z. (2009). Direct current therapy with/without lidocaine iontophoresis in myofascial pain syndrome. Bratisl Lek Listy, 110(3):185-91. PubMed: 19507642
- Macedo LB, et al. (2019). Iontophoresis in lateral epicondylitis: a randomized, double-blind clinical trial. J Shoulder Elbow Surg, 28(9):1743-1749. PubMed: 31447123
- Ibrahim NA, et al. (2024). Transdermal iontophoresis versus high power pain threshold ultrasound in Mechanical Neck Pain: a randomized controlled trial. J Orthop Surg Res, 19(1):658. PubMed: 39407315
- Nirschl RP, et al. (2003). Iontophoretic administration of dexamethasone sodium phosphate for acute epicondylitis: a randomized, double-blind, placebo-controlled study. Am J Sports Med, 31(2):189-95. PubMed: 12642251
The information in this article is for informational purposes only. Iontophoresis serves as a complement to medical treatment and does not replace it. Consult your physician if you have complaints. Individual results may vary.
