In the age of selfies and social media, everyone seems a little obsessed with their looks. Don’t worry, you are not alone: everyone wants to get that “beach body” fast!  And buying an abs stimulator before you share your pictures with others or appear in public at the beach might sound like a good option, especially if you don’t have time for the gym.

But let’s see if any of those devices can live up to their promises. In this article, you’ll learn how ab stimulators work, and the scientific evidence on their effectiveness, things personal trainers and medical experts say, as well as myths and half-truths surrounding these gadgets. 

What is the best ab stimulator? There are two most trusted brands of ab stimulators: the Flex Belt and the Slendertone. Both models are manufactured by Bio-Medical Research Ltd., an Irish company that has been known for its reliable and high-quality abdominal toning products for many years. Both brands employ electric muscle stimulation (EMS) technology that works by causing muscle contraction and relaxation.

While both are equipped with rechargeable batteries, the Flex Belt comes with an external battery, which is a clear advantage over the Slendertone made with a battery in the belt. External batteries make the belt much safer and more comfortable to wear.

The Flex Belt features medical-grade pads, unlike the Slendertone, which includes regular adhesive gel pads. The Flex Belt offers better adjustability — 150 intensity levels against only 100 options in the Slendertone. That said, the Slendertone seems to be a great option for beginners as it costs less money and is simpler to use.

Ab Stimulators Compared

1. The Flex Belt Abdominal Muscle Toner
Three medical-grade gel pads cover the central abs and external obliques, 10 toning programs and 150 intensity levels. External rechargeable battery.


2. Slendertone Evolve Abs
With 3 gel pads, the device tones 4 ab muscle groups. It has improved compression, 12 toning programs and 150 intensity levels. Rechargeable battery.


Do Ab Stimulators Work?

The principle behind ab stimulators is electrical stimulation of the muscles that causes them to contract, and thus, presumably, help them grow and strengthen, substituting regular exercise. Usually, electrodes in abs stimulators press against bare skin and send electrical pulses intermittently to the abdomen (or other parts of the body, if there are more detachable EMS pads that can come with the abs belt).

At lower levels, you may feel a slight tingling sensation, whereas at higher levels, your muscles start to contract. Typical descriptions for such devices promise results after 6 to 8 weeks of continuous use for 10 to 30 minutes per day.

Few people know that electrical muscle stimulators are regulated by the FDA, meaning that companies advertising or selling such devices must fully comply with the FDA requirements. Unfortunately, in reality, not all firms play by the book. Over the years, the Federal Trade Commission has filed numerous complaints against multiple electronic abdominal exercise belts for false advertisements and misleading claims. Electrical muscle stimulators (EMS) are cleared by the FDA for use in physical therapy and rehabilitation under medical supervision. 

Scientific Evidence: Effectiveness of Ab Trainers

One of the most well-known studies on the effects of electrical stimulation training on abdominal strength and endurance was published in the Journal of Sports Science and Medicine back in 2005, and was specifically conducted with the Slendertone FLEXTM belt (approved by the FDA). The researchers found that the use of the Slendertone significantly increased abdominal strength and endurance, as well as improved self-perceived abdominal firmness and tone.

The study suggested that the results could be attributed to the quality of the electrodes used in the Slendertone. The study was funded by Compex Technologies Inc., which engages in the design and manufacture of electrical stimulation products. 

Another earlier published study (2002) in the Journal of Strength and Conditioning Research sought to test some of the statements made by EMS manufacturers, such as decreasing body weight and fat, increasing muscle strength, and improving firmness and toning of the muscles. The study concluded that EMS had no significant effect on the muscles of a healthy individual. Unfortunately, the abstract of the study offered at PubMed doesn’t state the duration of the research, except that the people assigned to the EMS group underwent stimulation three times per week. Thus, it would be wrong to assume the complete ineffectiveness of abs stimulators given the limited data.

Study from as early as 1987 showed that electrical stimulation could be a valuable treatment in the early care of low-back pain in patients for maintaining strength and endurance of back muscles when a more active exercise programs were too painful to perform.

A more recent study published in Critical Care and Research Practice in 2012 concluded that using electrical muscle stimulation induced beneficial effects in muscle strength and early mobilization of critically ill patients. This is exactly what the FDA cleared many EMS devices for: treating various medical conditions, including re-education, relaxation of muscle spasms, prevention of muscle atrophy, complications resulting from a stroke, serious injury or rehabilitation from surgery.

In 2015, FDA issued a warning on the misrepresentation of EMS devices, alerting that none of them can be used for girth reduction, weight loss, cellulite removal, and bust or body shaping. However, there is still conflicting data among scientific studies, suggesting that EMS or so-called ab belts can in fact contribute to weight loss (although insignificant), especially if used in combination with regular exercise.

The 2011 study suggests that EMS can increase energy expenditure depending on stimulation intensity; thus, devices such as these can serve as an additional measure for weight loss. The study, though, was conducted outside of the US, and was funded by the National Science Council of the Republic of China, Taiwan, which, yet again, might imply that some of the research methods can be different to those used and accepted in the USA.

Irrespective of these rather discouraging findings, people still use ab belts as complementary devices in their regular exercise routines. The more important aspect in this kind of application is the purpose and expectations of the users of such devices.

Here’s what my husband, a certified personal trainer, says regarding the use of abdominal stimulators:

“It all depends on what goals the buyers of such devices pursue: to pump the muscles of the press, to lose weight, or to get fit with minimum time and effort? I believe that ab stimulators can be effectively used if there are no opportunities for training or as an important component of physical therapy at the initial stages of rehabilitation after injuries.

The abs stimulator will be ineffective for overweight people, individuals with a sedentary lifestyles, or those who never trained their muscles. The muscles of the press are usually synergists in physical training and daily activities, and thus, ab stimulators, which only forcefully contract the muscles, won’t help in the development of a neuromuscular connection.

If your goal is to lose weight, then the abs stimulator alone won’t help much either: EMS devices cause a calorie burning that is marginal at best. Weight loss is primarily a question of diet and calorie deficit, and only secondly - muscle training (especially large muscle groups). If you think that your stomach is your problem area, then your belly fat will most probably be the last thing to go.

If you need to work on your press muscles, then the so-called “Big Three” exercises, such as squats, deadlifts, and bench press, will do a great job. If you still would like to target your press muscles specifically, then you’d better find a certified instructor who can help you find the right exercises, even if you have certain restrictions or medical conditions.

You might be tempted to use ab-belts to reduce the time and effort spent on physical training, but the effectiveness of such devices is questionable.

However, there is an exception to the rule: EMS power suits for a full body workout. In addition to electrical impulses, people perform real exercises: twists, sit-ups, among others. This is not a solution for at-home workouts: this training should be supervised and directed by a certified instructor.”

UPD May 24 2021. Slendertone products are actually among the best ab belt toners on the market. The Slendertone CoreFit Abdominal Toning Belt uses clinically proven muscle stimulation technology, features 10 programs and 150 intensity levels. The device does the job well but the problem was with the way it was advertised.

Late in 2020, Lead plaintiff Jane Loomis of San Diego brought several causes of action against Slendertone Distribution, Inc., claiming that the company had been using false advertising and misleading statements regarding its product. These advertisements allegedly suggested that the Flex Belt would give benefits comparable to traditional exercise. In particular, the product was perceived as a tool that helped lose weight and create a “six-pack ab”. Buyers were allegedly tricked into thinking that the ab stimulator could give them well-defined abs without the need for exercise. According to the class-action lawsuit, there was little if any scientific evidence to support these claims.

 “Aside from some limited science showing some strength and endurance improvements to the abdominal muscle tissue as a result of extended [electrical muscle stimulator] use, no science supports the conclusion that use will rid belly fat, provide more attractive abs, contour the body, provide visible ‘six-pack’ abs, or that use can ever be a replacement for traditional exercise,” the class action complaint said.

In 2021 Slendertone Distribution Inc. agreed to pay $175,000 to settle a class-action lawsuit. Besides, the company will also stop advertising the Flex Belt in ways that mislead consumers. More importantly, the deal covers anyone in California who purchased the Slendertone Flex Belt in the period between May 7, 2015, and the date of the settlement approval. Buyers who fall within this criterion will get a refund ranging from 9.5% to 28% of the purchase price.

TOP Abs Stimulators Reviews

If you are not totally convinced yet that it’s better to go to the gym to pump up your press muscles, or you just want to give it a try, then here’s a brief overview of the ultimately popular ab stimulators.

1. The Flex Belt Abdominal Muscle Toner

Personally, I have picked this model and there is a number of reasons for that. Let’s start off with the fact that this is the first FDA-cleared and medical-grade ab stimulator designed for strengthening and toning abdominal muscles, something that says a lot about its quality. What I particularly like about this product is that it is was manufactured by Bio Medical Research Ltd, an Ireland-based international company that boasts 50-year experience in R&D of medical-grade devices.

Does Flex Belt work? The product was clinically tested, with the results showing the increased firmness of the ab muscles in almost 100% of the test users. The clinical trials lasted for 6 weeks and were conducted by scientists from the University of Wisconsin-La Crosse. I suppose that this is ample proof of high performance of the Flex Belt, unlike many other products that are being advertised by manufacturers without any substantial evidence of their efficacy. The key to success is the technology used, which has been applied by health care professionals for over 50 years.

 I would advise you to try this model not just because it worked for me, but also because it helped many other people as well. More importantly, the Flex Belt is the choice of celebrities. Many know model and reality TV star, Adrianne Curry. You may be curious to learn that this device has significantly contributed to her good physical condition. “It has taken my abs to a whole other level,” Adrianne says, highlighting the unit’s portability as one of its major benefits. Actress Denise Richards notes that with the Flex Belt she does not have to do multiple exercises to get all of her abs since the stimulator works all of them simultaneously.

I’d like to draw your attention to the fact that this device both stimulates the main stomach muscles and provides the user with the contraction of the upper and lower abs as well as the obliques. You will not have long to wait as the first results will be visible as soon as within several weeks. Just make sure that you follow the product label and do everything right. In particular, it is important to place the gel pads properly and replace them after 20 sessions of stimulation. I think this video explaining how to use it the right way will be helpful for you.

What do buyers say?

No wonder this product has gained a lot of positive reviews. The customers note that it was thoughtfully designed and comes with multiple programs and settings. They say that the stimulator is really effective and is able to considerably improve the abdominal muscle tone after several weeks of use.

For example, one elderly lady purchased it upon the advice of her brother after she noticed her abdominal fat being built up. Not only did she manage to improve her posture, but she also had most of her back pain relieved. To achieve these results, she has been using the device twice a day for over a month. Blogger #JaaackJack says that first she was skeptical about this product but eventually really liked using it as she felt like a little bit firmer after each session. “This is not going to give you six packs or anything like that, but it will help you tone and firm your muscles a little bit more,” the blogger stressed.

Last update on 2022-12-15 / Affiliate links / Images from Amazon Product Advertising API

Flex Belt: Check the current price

Slendertone Abs Abdominal Muscle Toner Review

If you think that the product mentioned above is too expensive for you, try this one. Slendertone is produced by the same manufacturer but is significantly cheaper and will cost you less than $100. Why? It comes with fewer toning programs (seven) and has 99 levels of intensity, whereas the Flex Belt comes with 150 ones. Is it that important? Well, some people believe that this makes no difference, and so do I. In my opinion, it is the technology and quality that makes the device efficient, while other features just add to the comfort and make the unit easier to use.

The thing is that Slendertone is also FDA-cleared and has been successfully tested by the company as well. Both models are high-quality products with the difference that the former is more feature-packed. This model is used in more than 5,000 clinics worldwide and has even been applied by astronauts.

Look at the results of a trial conducted by scientists of the University of Wisconsin-La Crosse in 2005. The study involved 24 persons who were stimulating their abs over the course of 8 weeks, turning on the device 5 days per week for about half an hour per session. An important condition was not to engage in any physical exercise during the trial.

The study has shown that those who used Slendertone had a 58-percent increase in abdominal strength and a 100-percent increase in abdominal endurance while their waist circumference decreased by more than 1.3 inches. The researchers have concluded that the product helps to improve the ab’s muscular strength and endurance but does not affect the body weight and the thickness of skinfolds.

Customer Reviews

I have analyzed the feedback and found out that half of the reviews are positive, with customers saying that the device works as advertised. However, some users complain that the belt size is not large enough for oversized people. Some customers have been using Slendertone units for years and report stable results. Some people are so enthusiastic about the device that they treat not only their abs but also their back and hips to tone up the muscles.

A 31-year-old Joanne says that the strength in her belly and back increased when she started using it. “All the vibrations are going down my legs, it is really pulling me on the sides and right down in the center,” Joanne explained, adding that it was not painful at all.

Advantages of Flex Belt & Slendertone Over Cheap Muscle Toners Under $40

Perhaps you have come across cheaper alternatives for under $40. Such products typically have a cheap-looking design and do not have much science behind them. The manufacturers would promise immediate results, positioning their products as “fat-burning” devices, whereas both Flex Belt and Slendertone stress that their stimulators are not weight-reduction products. Indeed, in order to shed extra pounds, you need to follow a diet and exercise regularly. What abs toning belts do is help you to achieve this goal.

Unlike cheap alternatives, Flex Belt and Slendertone are FDA-cleared to improve abdominal muscle tone, strengthen ab muscles, and develop a firmer abdomen. FDA clearance shows that the company is a serious manufacturer complying with all industry standards. More importantly, it indicates that the device works. Just like with watches. It might seem that they all work the same way, however, the technologies and components used make a huge difference. Well-made watches last for years to come while cheap models can break the next day of use.

As for the cheap ab stimulators, there is no information about any trials and tests that would indicate the effectiveness of the product. If you compare features, you can see that they have only 6 modes and 10 intensity levels compared to 10 programs and 100 intensity levels of the Slendertone. The Flex Belt abdominal trainer belt has even more levels of strength. Abs toners from these two trusted brands have been tested by independent scientists from the University of Wisconsin-La Crosse, and have proved to be effective.

Last update on 2022-12-15 / Affiliate links / Images from Amazon Product Advertising API

How to Use Ab Stimulators?

Fix the ab stimulator where you want to strengthen your muscles. For example, if you want to work on your abdominal muscles, then center the large middle pad over your belly button, ensuring the smaller pads lay on other abdominal muscles between your ribs and hipbones. Fasten the belt and make sure it fits perfectly on your skin. Follow the instructions for your belt closely and always start from a low-intensity level. Also start small: allow the ab belt to work no more than 10 minutes for the first time and then gradually increase the amount of time spent using the stimulator. If you feel something is not right, turn off your device immediately.

Please make sure that you understand that using products not cleared by the FDA can be dangerous. Over the years, there have been multiple reports of shocks, burns, and interference with other medical devices (like pacemakers) associated with the use of abdominal stimulators. So, if you think your product is malfunctioning, you should report it directly to the manufacturer or otherwise contact the FDA.

Ab Trainers Under $40

3. OSITO EMS Muscle Toner with 10 Gel Pads

The manufacturer guarantees results after 8 weeks of continuous use for 20 minutes, 1-2 times per day every day. There are 10 modes and 25 levels of intensity available. 3 in 1 means the device can be used for the abdomen, arms and legs. The product is lightweight and can be used anywhere, anytime. 

4. DOMAS Ab Belt Abdominal Muscle Toner | Best Budget Choice

The manufacturer guarantees results after using the ab belt for 4 weeks consecutive use for 12 minutes per day, 2-4 times per day every day. The gel pads should be changed after 15-20 times of continuing use. The ab pads can be used for abdomen, waist, arm and leg muscle training. There are 8 exercise modes and 20 intensity levels.

Suspiciously, there are many 5-star reviews that promise miracle results and cures for any type of problem, and all are very recent. It could be, though, that this abs stimulator really works well, but comments that it helps lose weight or pump up muscles as early as two weeks in continuous use, are certainly alarming and of questionable sincerity.

5.  BEN BELLE ABS Stimulator Muscle Toner

The manufacturer guarantees the results in toning, tightening, and strengthening of the body muscles after 6 to 8 weeks of consecutive use for 20 minutes per day, 5 days per week. The dark blue version has 9 exercise modes and 20 intensity levels: from warm-up to high-intensity levels. The gel sheets need to be replaced after the 30th consecutive use.

Expert Opinion: Dr. Arash Moradzadeh, Plastic Surgeon, K and B Surgical Center

Dr. Arash Moradzadeh, Plastic Surgeon, K and B Surgical Center

Arash Moradzadeh, MD, is trained in head and neck surgery as well as facial plastic and reconstructive surgery. He graduated from Washington University, where he received training in facial, sinus and neck procedures. Dr. Moradzadeh has published multiple scientific articles.

“We are using bioelectrical stimulation of your muscles with these paddles that go right into a gel pad. They have different modes, so depending on your fitness goals, we can change modes. And then it is gonna help build muscle sculpt out your body, increase your metabolism, which can aid in losing weight and also causes some improvement in the skin quality. This is working directly on your actual muscles. The idea is kind of like when you do a sit-up, your brain sends electrical signals to your muscles and causes them to contract. What we are doing now is a machine sending a very large signal to your muscle and making it contract. It is doing that in multiple different ways and directions… Ab belts are useful if you have a low back injury and you just want to deliver a little bit of energy to your muscle to tone it. But if you wanna get sculpted abs, ab belts are not going to work because it is only 10 milliamps of energy. That is not enough for the energy to deliver into the belly. The device that uses 30 milliamps of energy, penetrates all the way through to your muscle”.

Best-Selling Ab Stimulators Comparative Table

Most Popular

Products with 5-star rating


Product5 Stars Votes
MarCoolTrip MZ ABS Stimulator1578(15.2%)
Tabbic ABS Stimulator831(8%)
DOMAS Ab Belt483(4.7%)

Testing & Customers Reviews

We found reviews from real YouTube bloggers about the products from our article.

alpha m.: "I have seen abdominal toning super products for years. I've seen them and I have never tried them because I have immediately chalked them up to BS. So this was my chance to take it for a test drive and see if my assumptions were correct or hey maybe I've been missing out. I got abs. I got strong abs. I've been working with them for years. I'm the guy that should be testing Flex Belt.

Essentially you have an adjustable black neoprene belt on the flipside. You have three electrodes. You also have gel packs or pads that are replaceable, and you also have a remote control slash battery pack. There are ten different programs: and one is beginner, two is intermediate and from 3 up it's advanced. I got abs so the first time I set it on level 5. Then I started increasing the intensity. The intensity on this thing goes from 1 to 150. I didn't actually start feeling anything until about 30-40. When I got to around a hundred, it was like I was sitting on my damn. Now and then it relaxes, so it basically comes on the contraction it holds for about two to three seconds, then it relaxes for about five seconds, and then it comes back on. It does this for thirty minutes.

So I've been using the Flex Belt for the past week and I have been really sore, more specifically, my obliques on the side of my abs. I think it's probably because I don't do anything specifically targeting my obliques. They get work when I'm doing my other ab exercises in the gym, but as far as like targeting like contractions, it doesn't happen. So I've been incredibly sore. Does the belt work? Absolutely. This belt causes your abdominal muscles to contract. When you're exercising, when you do a crunch, what do you think you're doing? You're causing that muscle to engage and contract. The more you do that the more you're actually going to tone and firm.

So does the Flex Belt work? Will it strengthen and tone your abs? Absolutely. But will that mean that you can see them? No. To get your abs to show you need to reduce your body fat. There are two ways you're going to do that: a healthy diet and cardio. Without that, you can have the strongest sexiest abs in the world but if they're covered by a layer of fat you're never going to see them. It's a great product. It works your abs, but guys, like I said, it's not a shortcut. It's something to actually add. Is it going to eliminate my ab workouts in the gym? No. I'm going to supplement it. But it definitely is working things in a way that I apparently am not because I am crazy sore, and it hurts to laugh."

Last update on 2022-12-15 / Affiliate links / Images from Amazon Product Advertising API


Does an ab stimulator work if you have body hair?
Unfortunately, you will have to shave your body hair for the abs stimulators to work effectively.

What are the precautions I need to be aware of before using ab stimulators?
You cannot use any kind of EMS devices if you have an electronic implant (defibrillator, pacemaker, etc.) or suffer from a heart condition; you are pregnant; suffer from cancer, epilepsy, or have any other serious mental or physical dysfunction. Make sure you trust the supplier and/or manufacturer of the product. If in doubt, discontinue use immediately. Talk to a certified fitness instructor or medical professional to ensure you can use any such devices.

Can I use an ab belt while doing exercises like sit-ups?
Yes, you can. This combined approach will highly likely bring you more positive results than using the ab belt alone.

Will the ab stimulator give me muscle soreness?
Yes, it may. If your muscles are sore, try to switch to lower intensity next time you try your ab belt on. Also, you may as well expect redness of skin, which is natural, since the ab belt increases blood-flow to the stimulated areas. All these symptoms should fade away after some time. But if they persist, discontinue use, report to the manufacturer or talk to your doctor.


While promises of a beach body as early as 6 weeks after you start using the ab stimulator are certainly tempting, we advise you to speak to a healthcare professional and/or your fitness instructor and seek their professional advice before buying one.

A general rule goes as follows: if you want to lose weight, then you’d better start with a well-balanced diet and exercise; if you want to pump up your press muscles, then go to the gym and start exercising regularly; if you have medical conditions that require using an EMS device, then you will be prescribed one. Simple as that.

You can lose weight or work on your abs for your health or self-esteem, but you won’t be able to force nature to stop giving you some of these beautiful curves and folds that adorn and grace your body. So maybe it’s high time you learnt to love those folds back.

Read more: Compex Review — Best professional trusted Swiss brand — Muscle stimulator for pain treatment, back pain, muscle growth & strength.

Add comment