Can a TENS Unit Help With Scar Tissue?

A TENS unit can help with scar tissue, though the strongest evidence is for relieving scar-related pain and itching rather than physically reshaping the scar itself. In clinical studies, electrical stimulation applied to abnormal scars has reduced pain and itch scores dramatically within weeks. The question of whether TENS can actually soften, flatten, or remodel scar tissue is more complicated, and the honest answer involves understanding what TENS does well and where broader forms of electrical stimulation pick up where TENS leaves off.

What Happens When a Scar Forms

When skin is injured, the body repairs it through overlapping stages: bleeding stops, new tissue fills the wound, the surface re-covers itself, and then the underlying scaffold of proteins gets reorganized over months or even years.¹ That protein scaffold is mostly collagen, and the way collagen fibers line up determines whether you end up with a flat, pale scar or a thick, raised, uncomfortable one. In normal healing, collagen gradually reorganizes into a pattern that resembles the original skin, though never perfectly. In abnormal healing, collagen gets overproduced or poorly organized, leading to hypertrophic scars (raised but staying within the wound’s boundaries) or keloids (which grow beyond the original wound area).

Scar tissue that has already matured can be stiff, tight, and sometimes painful or itchy for years. This is where people start looking for solutions, and where TENS enters the picture.

How TENS Interacts With Scarred Tissue

TENS works by sending mild electrical currents through the skin to activate peripheral nerves.² It was originally developed as a pain management tool, and that remains its primary clinical use. The electrical pulses interfere with pain signals traveling to the brain and prompt the release of the body’s natural painkillers. But the effects go beyond pain relief.

One well-documented effect is increased local blood flow. When TENS is applied above the motor threshold, blood flow in the skin beneath the electrodes rises significantly compared to sham stimulation or no stimulation at all.³ This increase appears to be driven partly by the release of signaling molecules like substance P and calcitonin gene-related peptide, both of which dilate blood vessels and can accelerate tissue repair processes.⁴ The blood flow effect has also been measured at a distance from the electrode site when stimulation targets specific nerve pathways.⁵

Better blood flow to scarred skin matters because scar tissue is inherently less vascular than normal skin. Improved circulation can bring more oxygen and nutrients to the area, and that improved supply may help ongoing remodeling processes, even in older scars.

Where TENS Shines: Pain and Itch Relief

The most compelling clinical evidence for TENS and scar tissue is in symptom control. Scars, particularly burn scars and surgical scars, can be chronically painful and maddeningly itchy. These symptoms persist because nerves in and around scar tissue get trapped, compressed, or sensitized during the healing process.

In a study of patients with symptomatic abnormal scars, an electrical stimulation device produced significant drops in both pain and itch. Pain scores fell from a baseline of 7 to 0 within two months, and itch scores dropped from 6 to 0 over the same period. Overall scar scores also improved, falling from 14 to 11.⁶ Those are substantial improvements for symptoms that often resist conventional treatment.

Burn patients seem to benefit particularly. In a case report of a burn patient using TENS for itch relief, there was a 50 percent improvement in itching before TENS application and complete relief four hours after application within the first 16 days of use.⁷ A pilot study of patients with second- and third-degree burns found that TENS administered three times weekly for four weeks reduced average pain scores from 8.0 down to 1.0, with no adverse events.⁸ The frequency and intensity of the TENS signal matters: higher frequencies (around 80 to 100 Hz) raise both heat and mechanical pain thresholds, meaning the treatment can make scarred skin less sensitive to the kinds of stimuli that normally trigger discomfort.⁸

If your main frustration with a scar is that it hurts or itches, TENS has a reasonably strong track record. The relief tends to build over sessions rather than being a one-and-done fix, and most studies describe protocols lasting several weeks.

Can Electrical Stimulation Actually Remodel Scar Tissue?

Here is where things get more nuanced, and where an important distinction matters. TENS is one type of electrical stimulation, designed mainly to target nerves. But researchers studying scar remodeling often use other forms of electrical stimulation, including direct current, microcurrent, and biphasic alternating current, that target the cells responsible for building and breaking down collagen. The findings are promising but apply more to electrical stimulation as a category than to a standard consumer TENS unit specifically.

At the cellular level, electrical fields do remarkable things to fibroblasts, the cells that produce collagen. When fibroblasts are exposed to electrical stimulation in laboratory settings, they become more active, migrate faster, and produce more of the contractile fibers that pull wound edges together.⁹ The intensity and duration of stimulation influence how much the cells respond, with staining for contractile fibers increasing proportionally with both exposure time and electrical intensity.⁹

Electrical fields also push fibroblasts to transform into myofibroblasts, the specialized cells that contract wounds and reorganize the collagen matrix. Research has confirmed that key markers of this transformation increase significantly when fibroblasts are exposed to electric fields, along with increased production of both type I and type III collagen.¹⁰ In 3D hydrogel experiments designed to mimic actual wound environments, electrically stimulated cells showed the highest density, the most elongation, and the best network formation.¹¹

During the later remodeling phase of healing, biphasic currents can modulate TGF-beta signaling, a key molecular pathway that controls how much collagen gets deposited. By dialing down excessive TGF-beta activity, electrical stimulation may reduce abnormal collagen buildup and improve the mechanical properties of the resulting scar.¹² A related finding involves a protein called Cavin-2: when fibroblasts were stimulated with alternating current, Cavin-2 expression decreased, which altered the cellular membrane in ways that changed collagen production and the expression of enzymes that break collagen down.¹³ That balance between collagen production and collagen breakdown is exactly what determines whether a scar stays thick and stiff or gradually softens over time.

Raised and Keloid Scars

Hypertrophic scars and keloids are among the most stubborn types of scar tissue, and they are the ones most people are hoping to treat when they search for solutions. The evidence here is early but intriguing.

An animal study using positive-polarity electrical stimulation on surgically induced wounds reported that the treatment reduced scar thickness and hypertrophic scar formation.¹⁴ This suggests that electrical stimulation applied during or shortly after wound healing could prevent the overproduction of collagen that leads to raised scars in the first place.

For keloids specifically, a scoping review found that electrical stimulation counters several features of keloid biology. It reduces mast cell counts (mast cells drive inflammation and fibrosis in keloids), shifts the immune cell balance in ways that favor normal healing, promotes new blood vessel formation, and controls both the orientation and location of fibroblasts within the tissue. An alternating current orients fibroblasts perpendicular to the current direction without causing them to migrate in unwanted ways.¹⁵ Fibroblast orientation matters because one hallmark of abnormal scars is disorganized collagen. Getting the cells to line up in an orderly fashion could theoretically produce more normal-looking tissue.

A systematic review of microcurrent electrical stimulation for tissue healing and scar modulation examined eleven studies from 2012 to 2024 and concluded that the technique may enhance wound healing and improve scar outcomes, but also flagged that results are inconsistent because of wide variability in treatment protocols, patient populations, and how scars were assessed.¹⁶ That inconsistency is the honest state of the science right now. The biological mechanisms are plausible and increasingly well understood, but standardized clinical protocols do not yet exist.

TENS Versus Other Electrical Stimulation Devices

If you own a TENS unit and are hoping it will do everything the research describes, it is worth understanding where TENS fits among the broader family of electrical stimulation devices. They are not interchangeable.

A standard consumer TENS unit delivers relatively high-frequency, low-intensity pulses designed to stimulate sensory nerves. It works well for pain and itch because it essentially overwhelms pain signals and triggers endorphin release. But many of the scar-remodeling effects described in the research involve different types of electrical stimulation: microcurrent devices that deliver currents below the level you can feel, direct current devices that create polarity effects, or specific biphasic waveforms tuned to influence cellular behavior.

The body’s own wound-healing process actually generates small electrical currents. When skin is injured, a voltage difference develops between the wound and surrounding healthy tissue, and cells migrate along these electrical gradients. Researchers studying scar remodeling are essentially trying to mimic or enhance these endogenous electrical signals, and that requires precise control over current type, intensity, and duration.¹⁷ A consumer TENS unit gives you control over frequency and intensity but was not designed with scar remodeling in mind.

That said, the lines blur more than you might expect. TENS units do increase local blood flow and do trigger the release of neuropeptides that participate in tissue repair.⁴ So while a TENS unit probably will not reproduce the specific cellular effects seen in laboratory electrical stimulation studies, it is not doing nothing to the scar beyond pain relief. It is just unlikely to be the optimal tool for structural remodeling.

Practical Considerations for Using TENS on Scars

If you decide to try TENS on scar tissue, a few practical points are worth knowing. First, electrode placement matters. You generally want the electrodes placed on or flanking the scar, not directly on open or freshly healing wounds. TENS is for closed, healed scars. Most practitioners recommend waiting until the wound has fully closed and any sutures have been removed.

For pain and itch, the clinical protocols that have shown results typically use sessions of 20 to 30 minutes, repeated several times per week over a period of weeks. The burn study that achieved dramatic pain reductions used 30-minute sessions three times weekly for four weeks.⁸ Consistency seems to matter more than session length.

Intensity is another variable. For pain relief, you want the stimulation strong enough to feel clearly but not painful, often described as a strong but comfortable tingling. The blood flow benefits appear to require intensities above the motor threshold, meaning strong enough to cause a slight visible muscle twitch.³ Many people use TENS at intensities well below this, which may limit the tissue-level effects.

Standard safety precautions apply: avoid using TENS if you have a pacemaker or other implanted electrical device, do not place electrodes over the front of the neck or directly over the eyes, and stop if the skin under the electrodes becomes irritated. Scarred skin can sometimes have altered sensation, meaning you might not feel an intensity that would normally be uncomfortable, so start low and increase gradually.

What TENS Cannot Do

Setting realistic expectations helps. TENS is unlikely to flatten a mature keloid that has been present for years. It will not erase a scar or make it invisible. The structural remodeling effects observed in laboratory studies involve precisely controlled electrical parameters that a consumer TENS unit does not replicate. The clinical evidence for TENS changing the actual physical structure of scars is much thinner than the evidence for symptom relief.

If you are dealing with a problematic scar and want to address both symptoms and appearance, TENS is best thought of as one part of a broader approach. Silicone sheeting, pressure therapy, massage, and sometimes corticosteroid injections or laser treatments are the established interventions for scar remodeling. TENS can complement these by making the scar more comfortable and by improving local blood flow, which may enhance the effectiveness of other treatments.

The gap between the laboratory science and the clinical reality is real but likely to narrow. Researchers are actively working on what they call “scar-oriented electroceutical design,” essentially engineering electrical devices specifically tuned to influence scar biology rather than repurposing pain-relief technology.¹⁷ Future devices may combine the nerve-stimulating benefits of TENS with the cellular effects of microcurrent or biphasic stimulation in a single home-use unit.

How Scar Changes Are Measured

One challenge in scar research is that scars are hard to measure objectively. A scar might look better to you but still have the same internal structure, or it might be softening internally while looking the same on the surface. Researchers are developing high-frequency ultrasound techniques that can assess the elastic properties of scar tissue noninvasively, using sound waves to track how stiff or pliable the tissue is at different depths.¹⁸ Surface wave elastography offers another approach, measuring how vibrations travel through scar tissue compared to normal skin.¹⁹

These technologies are not available in most clinics yet, but they are relevant to anyone hoping that TENS or other electrical stimulation will change their scar. Right now, most people assess scar improvement by touch and appearance, which is subjective and can be influenced by wishful thinking. As objective measurement tools become more accessible, it will become much clearer which electrical stimulation protocols actually produce structural changes versus which ones mainly relieve symptoms. For now, if your scar feels less painful and itchy after a few weeks of TENS use, that is a real and meaningful benefit, even if the scar itself has not visibly changed.

1
PubMed Central. Extracellular Matrix Reorganization During Wound Healing and Its Impact on Abnormal Scarring
2
PubMed Central. Transcutaneous Electrical Nerve Stimulation (TENS) A Possible Aid for Pain Relief in Developing Countries?
3
Archives of Physical Medicine and Rehabilitation. Transcutaneous electric nerve stimulation: The effect of intensity on local and distal cutaneous blood flow and skin temperature in healthy subjects
4
PubMed Central. The effects of transcutaneous electrical nerve stimulation on tissue repair: A literature review
5
Journal of Acupuncture and Meridian Studies. The Effect of Transcutaneous Electrical Nerve Stimulation of Sympathetic Ganglions and Acupuncture Points on Distal Blood Flow
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PubMed. Treatment of symptomatic abnormal skin scars with electrical stimulation
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PubMed. The use of TENS for pruritus relief in the burns patient: an individual case report
8
Nature Publishing Group. Neuromodulation strategies in postburn care for pain rehabilitation and scar remodelling
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PLOS ONE. Electrical Stimulation Promotes Wound Healing by Enhancing Dermal Fibroblast Activity and Promoting Myofibroblast Transdifferentiation
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International Journal of Medical Sciences. Electric field promotes dermal fibroblast transdifferentiation through activation of RhoA/ROCK1 pathway
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PubMed Central. The Synergistic Effect of Electrical Stimulation and Dermal Fibroblast Cells-Laden 3D Conductive Hydrogel for Full-Thickness Wound Healing
12
Frontiers in Bioengineering and Biotechnology. Advances in electrical stimulation for wound healing
13
PubMed Central. Electrical Stimulation Using a Low-Frequency and Low-Intensity Alternating Current Modulates Type I Procollagen Production and MMP-1 Expression in Dermal Fibroblasts
14
PubMed. Exogenous electric current can reduce the formation of hypertrophic scars
15
PubMed. Can Electrical Stimulation Prevent Recurrence of Keloid Scars? A Scoping Review
16
PubMed. Role of Microcurrent Electrical Stimulation in Tissue Healing and Scar Modulation: A Systematic Review
17
PubMed Central. Bioelectric modulation of scar fate in wound repair: Mechanisms, dosimetry, and scar-oriented electroceutical design
18
PubMed. High-Frequency Ultrasound Elastography for Assessing Elastic Properties of Skin and Scars
19
The Journal of the Acoustical Society of America. An ultrasound surface wave elastography technique for non-invasive measurement of scar tissue