How to Evaluate a TENS unit?

The Tens unit is a device that makes use of electrical current for nerve stimulation and restores them in the case of inflammability. People aged 25 to 65+ years old utilize these machines with particular relief to affected areas. The electrical nerve stimulation also makes use of low voltage current that relieves pain efficiently. The system is non-invasive too.

Buying a Tens Machine

Before purchasing a suitable TENS machine, one should assess the use of the machine and also the need for oneself. Once you have established the veracity of a TENS machine, one should look forward to evaluating the right model in accordance to pain relief one is expecting from the machine. One should also check for the feature set, the price along with the FDA clearance. Consider the number of electrodes, channels and other attributes before making the investment.

Check the FDA clearance for the Tens Unit as a class II medical device

If you come across a product that is not under regulation, you should avoid using it. Companies are not allowed to market products as medical devices unless they have FDA clearance. An FDA clearance makes sure that the product is well-designed and safe to use for the specific age group.

Check for Relevant Features that you would need

As part of a systematic assessment approach, one should check out for programs and modes in a machine.Not many OTC Tens units include preset programs and some of them are designed to make it simpler for users. When you are checking the basic system, you will want to check with the buttons and then consider if the controls are fine. The buttons, which trigger power surge through the electrodes, may not be handy to use or comfortable enough. The buttons might not alleviate pain as you intend it to. The controls need to be covered to avoid any accidental adjustment of the overall settings.

Top most Factors to be checked before making the purchase

Size of Display:

When investing in a TENS unit, the size of display matters since one needs to easily read the display. Also, the controls need to be well labelled and changes can be affected easily. The battery compartment should be accessible to users while the AC adapter slot will help you set it up near a power source without having to depend on batteries. Some machines have very fewer modes but possess better treatment options. Most users prefer the ones with good preset programs so that they can be easily operated.


Most Tens units in the market are the dual channel and also feature different intensity controls.Some TENS units include spare electrodes or gel and sometimes a spare battery within a case. Do check if one can make changes to the available items. As mentioned above, check if they include a single, dual or four channels and if the intensity control is independent for each of the channels. More channels will help one who is relying on more pads to get oneself treated. Each channel has two pads and the dual channel device will include two or four pads. One can never use a machine with a single channel with more than two pads.

Intensity Levels:

In terms of intensity, one should check out the following criteria:

  • The number of intensity levels although it does not reflect on the overall power capacity of the device. If a machine has 50 levels, it does not indicate it has more power than the Tens unit with 25 levels.A 50-level device works in increments of 2% at any point of time while a machine with 25 levels works with increments of 4%.
  • Check for the overall power of the device and then the intensity levels and its adjustment settings
  • Some manufacturers specify intensity in mA, which isn’t available on all devices. It would be a matter of prudence to assess and take user feedback into consideration along with reviews.

Ease of use Consider how the Tens unit is operated and if it is easy to use for everyone who needs it at home. Check out the primary buttons and controls and the navigation process.


The new portable devices usually feature lithium rechargeable batteries, which make it advantageous and user-friendly in terms of convenience, savings and efficiency. Check the process through which the battery gets charged, and the duration of each battery charge. If the machine uses batteries instead, check the type of batteries, the number of batteries, the price involved and the like. Rechargeable sets might include a higher initial investment, but check out if the systems using replacement batteries actually save money and are convenient enough in the long run.

Size and Portability:

Portability is one of the prime factors before you come to a final decision of selecting a Tens unit. The size of the device along with its weight, the addition of a carrying case and affordability are some factors that will affect your buying decision. Check out the accessories that are packaged with the device and if they are worth the investment compared to similar Tens machine units found in the market?


A majority of machines include a one-year warranty, but some offer a warranty period of 90-days. Check out the length of the warranty period, the coverage factor, the robustness of the machine as well as the reputation of the company from other buyers.


TENS machines come in many shapes and sizes, include a variety of features and also carry different price tags. The prices are way skewed as some are priced at $30 while some go until $300, based on its internal capacity, batteries, channels and the like. It is like buying a smartphone with your money, as some prefer to have loaded devices with better specifications for daily use. The same analogy applies to these machines, which boast of better specifications, build and performance as the price shoot up.

Not all features would be required in this regard, hence those within a budget can invest in affordable Tens machines for their daily personal use. Before buying a product based on price, check whether the product is well priced, their comparison with other units with nearly similar specifications, the accessories included in the kit along with the operational costs involved with respect to other Tens units.


Tens machines do not have to cost you a bomb. Most medium-range machines have received excellent user feedback and the price is usually excellent too. Also, the other factors are important too. Check out for intensity levels, the portability factor, the batteries included in the machine, the types of channels embedded within your device and the basic requirement and reason for you to buy a particular machine. Also, check out for accessories that are being packaged with the Tens unit and you might have a win-win deal altogether.