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Many brands offer transcutaneous electrical nerve stimulation (TENS) units that can help reduce pain. They are suitable for people with sciatica, arthritis, and fibromyalgia. However, they may not be safe for people who are pregnant or have other conditions.

This article describes what TENS units are and explores some products available to buy online. It also lists some considerations a person should make before purchasing and answers frequently asked questions about TENS units.

A quick look at the best TENS units

TENS is a noninvasive pain relief management device. It sends a mild electrical current through electrodes attached to the skin.

Electrical muscle stimulation (EMS) is a physical therapy and fitness technique that also uses electrodes to transmit electrical impulses.

A TENS unit comes with:

  • a battery-powered generator
  • a single or dual channel
  • lead cables
  • sticky patches, or electrodes

A person places the electrodes on or around the painful area. The TENS device stimulates the nerve endings to produce endorphins to reduce pain. Endorphins block the brain’s transmission of pain signals.

Doctors may recommend using a TENS unit for acute and chronic pain that results from surgery and other health conditions, including:

A 2020 study reviewed the effects of a 4-week TENS treatment in women with fibromyalgia. Researchers found significant improvements in movement-evoked pain and fatigue.

A 2021 study also noted that TENS therapy provided immediate pain relief in people with chronic low back pain.

According to another 2021 study, TENS units are safe for people who have endometriosis and menstrual cramps, as they can alleviate pain and manage primary dysmenorrhea.

Also, one 2020 review of 26 studies found that TENS can significantly reduce pain during labor.

Learn more about TENS.

Using TENS is generally safe and does not have side effects. However, the adhesive pads can cause allergic reactions, but special nonallergic pads are available.

TENS can also cause metallic or electronic implants, such as defibrillators and cardiac pacemakers, to malfunction.

A person should not use TENS machines while driving, operating machinery, or while in contact with water, such as bathing, showering, or swimming.

A person should never place TENS pads on the following areas:

  • temples
  • front or sides of the neck
  • mouth
  • eyes
  • numb skin
  • irritated or broken skin
  • varicose veins
  • the chest and upper back simultaneously

Also, people with any of the following conditions should not use TENS units:

TENS is safe during pregnancy, but a person with a history of early miscarriage or a previous abortion should not use TENS while pregnant.

If a person has had complications in their current pregnancy, they should not use TENS.

A person should be careful when placing the TENS electrodes during pregnancy. Putting them in certain locations can cause labor contractions. These areas include:

  • web space between thumb
  • lower half of the leg or ankle
  • top of the shoulders

If a person develops labor contractions while using TENS, they should immediately turn off the machine and speak with a doctor.

A person must always follow the manufacturer’s instructions and stop using a TENS machine that is faulty, makes pain worse, or causes skin reactions.

People should consult a doctor or physical therapist to determine how and when to use a TENS unit.

Medical News Today chooses TENS units based on the following criteria where possible:

  • Price: MNT chooses products available for a wide range of budgets.
  • Brand reputation: MNT chooses brands that adhere to industry best practices and that offer reliable customer service and support.
  • Safety: MNT selects products from brands that do not make unsupported health claims. Products will include safety features, clear instructions, and information about side effects.

Below are seven of the best TENS units available online.

Please note that the writer of this article has not tried these products. All information presented is purely research-based and correct at the time of publication.

Medical News Today follows a strict product selection and vetting process. Learn more here.

Best for personalized settings suggestions: Therabody PowerDot 2.0 Duo

  • Advantages: discreet, app-controlled settings, personalized to user’s information
  • Disadvantage: pricier than other options
  • Who it is best for: people who want app support during use
  • Price: $349

The PowerDot 2.0 Duo connects to a person’s smart device via Bluetooth. It uses TENS and neuromuscular electrical stimulation (NMES).

It comes with a Therabody app that serves as an intensity controller and guides a person through program selection and pad placement.

The app also offers personalized adjustments based on the data the user provides as well as access to its community.

The company recommends it for period pain and muscle recovery.

In addition, the product features 12 stimulation modes and 20 intensity settings. It also comes with:

  • a lightweight design
  • a rechargeable battery
  • a protective carrying case
  • a single channel
  • 1-year warranty

A person can use the company’s 60-day trial to test the product before committing to a purchase.

Positive reviews mention it is easy to use and helpful for recovery after exercise. Negative reviews focus on problems connecting to smart devices.

A person can order this TENS unit online for $349.

Best for a range of massage simulations: HealthmateForever YK15AB TENS Unit

  • Advantages: offers multiple massage simulations, lifetime warranty
  • Disadvantages: more expensive than other brands, not rechargeable
  • Who it is best for: people looking to simulate massage
  • Price: around $100

This device comes with 15 modes, nine auto-stimulation programs, and 20 levels of intensity. It uses TENS and EMS.

A person can choose which area of the body they wish to target with visual diagrams on the screen. Settings are labeled according to the area of the body for which they are suitable.

The EMS settings aim to mimic the feeling of massage. Users can choose their preferred method of massages, such as kneading, acupuncture, and cupping. As a result, this TENS machine may be best suited to people who wish to simulate the feeling of massage while they use the machine to relieve pain.

This device has four outputs that allow a person to use eight pads simultaneously. It also comes with a built-in belt clip.

Other features include:

  • adjustable speed and intensity
  • auto shut-off
  • a dual channel
  • a lifetime warranty

Positive reviews comment that it is effective at relaxing muscles and relieving pain. However, critical reviews state it did not help with sciatic pain. Some users felt it was not cost-effective to use disposable batteries over a long period of time.

The HealthmateForever YK15AB TENS Unit costs around $100.

Best wireless design: iReliev TENS + EMS Therapeutic Wearable System

  • Advantage: longer warranty than other brands
  • Disadvantage: unsuitable for small budgets
  • Who it is best for: people who need pain relief on the go
  • Price: around $190

The iReliev has a wireless, low profile design for discreet, convenient use. A person can wear the pods on the go.

The unit comes with two pods that can be programmed as an isolated channel or paired together.

It uses TENS and EMS.

The hand control can support up to four channels, allowing people to upgrade their devices for expanded coverage.

The device also has other features, such as:

  • 14 stimulation modes
  • an EMS system
  • a rechargeable power source
  • wireless technology
  • a 2-year arranty

Reviews on the brand’s website mention it is convenient, effectively relieves pain, and the pads adhere well to the skin.

Critical reviews mention problems with pairing pods with the control unit. Some users received faulty products.

A person can order the iReliev TENS + EMS Therapeutic Wearable System for around $190.

Best for short-term pain relief: HiDow Spot

  • Advantage: rechargeable, wireless, portable, covers large surface area
  • Disadvantage: has a maximum of four modes
  • Who it is best for: people needing short-term pain relief
  • Price: around $119

This wireless TENS machine has four modes. The manufacturer describes it as lightweight, portable, and suitable for people to use on the go.

The manufacturers claim it is suitable for muscle recovery for short-term pain. Buyers can use it on their back, hips, abdomen, and joints.

This TENS machine may suit people who would like to support their muscle recovery and reduce short-term post-workout pain.

There are no reviews of this TENS machine on the company website.

A person can order the HiDow Spot online for around $119.

Best affordable option: TENKER TENS Unit

  • Advantage: affordable, rechargeable, 24 modes
  • Disadvantage: users report poor electrode quality
  • Who it is best for: people with smaller budgets
  • Price: about $39

This TENS machine is an affordable, rechargeable option.

It has 24 TENS modes and 20 levels of intensity. It also has a timer that people can set for between 10–60 minutes.

This machine features dual output, meaning a person can use different settings for different areas of the body simultaneously.

The manufacturer writes that the battery lasts for 10 hours.

This machine is significantly more affordable than other options, making it suitable for people working with smaller budgets.

Positive reviews mention the pack includes a storage device for the electrodes, which some buyers found useful. Others write that it helps loosen muscle tension and is powerful enough for people needing more intense pain relief.

However, critical reviews frequently state that the pads are not sticky enough.

A person can order the TENKER TENS machine online for around $39.

Best for foot pain: Omron Electrotherapy TENS

  • Advantage: preset programs for targeted pain relief, affordable, portable, discreet size
  • Disadvantage: fewer modes than other units, comes with one pair of electrodes
  • Who it is best for: people with foot pain
  • Price: around $47

This TENS machine from Omron may be best suited to a person with foot pain, as it has a preset program to ease pain in the legs and feet.

It also has preset programs for arm and shoulder pain and for the lower back. There is a knead and steady massage mode available and 10 intensity levels.

Its design is small and discreet, and it is designed for people to use on the go.

The TENS unit comes with one pair of long-life electrode pads that the manufacturer claims can be used up to 150 times.

Positive reviews write that it is practical and easy to use.

Negative reviews mention the wiring is not durable and it may not be powerful enough for some.

A person can order the Omron Electrotherapy TENS machine online for around $47.

Best for period pain: Ovira Period Pain Relief Device

  • Advantage: suitable for period pain, discreet, portable, health insurance covered, all-day battery life
  • Disadvantage: has one massage or vibration mode
  • Who it is best for: those with period pain
  • Price: around $139

This TENS machine is specifically designed to ease period pain.

The pack includes two pads, a TENS machine, charging cables, and a storage pouch. It has a very discreet, small design so that people can wear it all day under their clothes. The machine clips onto underwear.

The company writes that a person sticks the electrodes onto their stomach or back. The machine sends electrical pulses to redirect pain signals.

According to Ovira, the battery lasts all day. Positive reviews mention that the device offers immediate relief from period pain.

However, other reviewers note that it was not effective for intense period pain.

The company offers a 100-day free trial, and a person may be able to claim this purchase on their health insurance. The device also comes with a 2-year warranty.

A person can order the Ovira Period Pain Relief Device online for around $139.

The table below compares each of the TENS machines for price, the number of settings, and their advantages and disadvantages.

Price Who it is best forNumber of modesAdvantagesDisadvantages
Therabody$349people who want support during use12• personalized setting suggestions
• comes with app
• discreet
expensive
Healthmate Foreveraround $100people who want massage simulation15• includes range of massage types
• lifetime warranty
• not rechargeable
• more expensive
iRelievaround $190people needing pain relief on the go14long warrantyexpensive
HiDowaround $119people needing short-term pain relief4• rechargeable
• wireless
• portable
• large surface area
maximum of 4 modes
TENKERaround $39people on a budget24• affordable
• rechargeable
• 24 modes
users report poor electrode quality
Omronaround $47people with foot pain10• preset programs for targeted pain relief
• affordable
• portable
• discreet size
• fewer modes than other units
• comes with one pair of electrodes
Oviraaround $139people with period painnot stated• discreet
• suitable for period pain
• portable
• health insurance covered
• all-day battery life
has one massage or vibration mode

TENS units can be used daily. A person should start on a low setting and gradually increase it to find the right intensity.

A person can use them to help ease pain from a wide range of conditions, including:

Generally, a person will place the pads at least 1 inch apart on the painful area.

If a person experiences side effects from using a TENS machine, they should stop using it and contact a doctor.

TENS units can provide pain relief with few to no side effects.

However, a person should speak with a doctor before using a TENS unit. A doctor will be able to diagnose the cause of a person’s pain. They can advise on whether a TENS machine will be a safe and suitable method of pain relief.

TENS machines are not safe for everyone. People should not use TENS machines without speaking with a doctor first if they:

Learn more about TENS for overactive bladder.

If a person develops skin irritation from the pads, they should stop using the TENS machine and speak with a doctor. There may be hypoallergenic pads available.

Features to consider when choosing a TENS unit include:

  • Treatment modes: Units with various treatment modes allow a person to choose a mode that offers relief for a specific body area.
  • Intensity levels: These allow the user to adjust the unit’s power based on their tolerance. Digital adjustments offer more graded control than dials or knobs.
  • Portability: Some devices have a small and lightweight design. These might suit people who wish to use the product while working.
  • Timer: Many devices come with preset timers, while others feature an adjustable timer. Most machines also come with an auto shut-off feature.
  • Channels: TENS units with dual channels allow people to use each channel with different modes and intensities.
  • Power source: Some devices use rechargeable batteries, while others use disposable ones. A person should consider how long a full charge can last if they use it continuously, and how cost-effective units will be if they need to regularly replace batteries.
  • EMS: Some TENS units have EMS functions as well. EMS may help strengthen and stimulate muscles and may be ideal for rehabilitation and improving sports performance. A 2020 study found EMS effective in improving the quality of life and physical outcomes in people with advanced stages of cancer.

Below, we answer some of the top frequently asked questions about TENS units.

What is the difference between TENS and EMS?

While both TENS and EMS apply electrical currents in the body, TENS aims to relieve pain. EMS contracts the muscles and is suitable for rehabilitation and strength performance.

Does TENS hurt?

Typically, TENS does not hurt. However, people will have different thresholds regarding how comfortable they find higher intensity TENS settings.

A person should start using lower settings and gradually work up, only using an intensity level with which they are comfortable.

Does TENS help sciatica?

TENS may relieve a person’s discomfort from sciatica pain and help them regain mobility to perform daily activities.

Is TENS safe?

TENS is a noninvasive, nonaddictive pain relief option that does not cause any side effects.

Are TENS units worth it?

TENS units can be an effective and affordable method of pain relief, depending on the TENS machine a person chooses. Additionally, research has found TENS to have few to no side effects.

A person should speak with a doctor to determine whether a TENS machine will be effective for their pain.

TENS units can help reduce pain in people with arthritis, sciatica, period pain, and other conditions.

They are available without a prescription.

However, people should first consult a medical professional to diagnose their pain and help them find the best TENS unit that suits their needs.