Boots Maternity TENS Machines. Do they work?

TENS MachineSo, in a few weeks, Quackometer Manor will have a new arrival, and like all good middle class parents-to-be, we are currently attending compulsory NCT classes, to learn all the mystical secrets of giving birth and looking after a little one.

It’s all a bit candles and crystals, and when we are not sat on the floor with the tips of our tongues sticking out, using crayons to express our feelings about various aspects of parenthood, we occasionally discuss facts.

At our last meeting, we were given a task. Go away and each couple should research and summarise one of the pain relief options available to women. Epidurals, gas and air, etc.

We were given TENS machines.

Oh joy.

Here is what we found out. TENS machines (Transcutaneous Electrical Nerve Stimulation) are small devices that deliver mild electrical shocks to the skin, which according to the Boots Maternity site, “stimulates your body’s own natural defences against pain.” The idea is that when contractions start you can attach the electrical pads to your body and the small shocks will either “block the pain signal travelling up the spine” or “promote the release of endorphins – your body’s own natural pain killer”.

Boots Maternity TENS RentalThe machines are quite expensive to buy, so Boots offer a handy rental service. For about £30, you can rent one for the four weeks around your due date, take it to the hospital, and often, the midwife will help you strap it on.

We are told:

Large reusable pads go each side of your spine in two positions to intercept the nerves carrying pain from all over the abdomen.

Boots Maternity TENS has different programs that you select with one button press to cope with the changing pattern of pain as labour progresses.

Press the built-in boost button to increase the effect during contractions

Boots claim that the TENS machine is “safe and easy to use, puts you in controls and offers significant reduction of pain.”

Are these things true? Let’s explore the origins of these devices and look at the evidence.

One of the first advocates of electrocution as a cure was an unlikely character: John Wesley, the founder of Methodism. His biggest selling book was not a religious text, but an 18th Century self-help book promoting natural cures for all illnesses. He believed physicians and apothecaries conspired to keep people ill with worthless and dangerous chemical medicines and saw nature as the source of remedies – available to all. In many ways, he offers us a prototype of the advocate of ‘natural health’, the modern day vitamin sales person and homeopath, convinced of their own findings and hostile to science.

Most of Wesley’s cures consist of cold bathing and consuming turnips. But in a act of contradiction to his themes of naturalness and availability to the common man, he advocates the use of electrical devices to administer electrical shocks. All sorts of illnesses and complaints can be cured and alleviated by shocking. His list includes blindness, burns, deafness, fits, headache, lameness, leprosy, pains in the stomach, sciatica, toothache and ulcers. His instructions for using the electrical devices were to,

give fifty, or even hundred small shocks, each time; but let them be so gentle as not to terrify the patient in the least.

Over the next two centuries a huge industry would build up in quack electrical devices designed for personal and family use. Mass production in Victorian times allowed manufacturers to sell boxed electric shock machines to those who believed in electricity’s curative properties.


Thousands of these devices were made, often in very fine an elaborate wooden cases designed to impress. Some used rotating magnets and others batteries to produce a current capable of creating tingling in the skin. Quack doctors made extravagant claims about the healing properties of their devices.

These devices can still be bought on auction sites although prices can be quite high as there is strong demand from people who belong to something called the BDSM community.

And so to the modern day and such devices have been given a modern medical sounding name and are widely promoted and sold as pain relieving devices. But, just because their origins are in quackery and charlatanism does not mean that they might not be valuable. What is the evidence for these devices effectiveness?

The Cochrane Collaboration, a group of independent, volunteer researchers, has conducted a review of the available evidence. It is quite interesting reading. They looked over 19 reviews that considered the experiences of 1671 women giving birth. The results are pretty clear: women using TENS gave similar scores to their experienced level of pain as those in control groups – those not using TENS. This, to me, is quite surprising as, even if TENS were ineffective, it is hard to conduct fair trails as it is quite obvious if you are in the test or control groups. How do you administer placebo electric shocks? The failure to consistently show benefit would strongly suggest the TENS device was not creating a lower level of pain in women. The vast majority of women using TENS go on to use additional analgesic pain reduction methods.

The results are pretty clear: women using TENS gave similar scores to their experienced level of pain as those in control groups.

But, what is interesting is that “many women said they would be willing to use TENS again in a future labour”. So, whilst TENS does not reduce experienced pain, it appears to create the illusion that it has.

This is fascinating stuff. Like so much quackery, the claims do not stand up to scrutiny and yet there may well be some side benefits that are rarely discussed. But is this side benefit of a sense of control over pain sufficient to recommend TENS? Obviously, people may not hand over hard cash if they know that all they are going to get is an illusory sense that pain has been reduced rather than a real one. Nonetheless, a feeling of control over what is happening may be important to many women.

One thing that is clear is that Boots are clearly misleading women when they state on their web site that TENS can offer “significant reduction of pain”. But we have learned recently that Boots, and the pharmacists who work for them, cannot be trusted to provide clear and truthful statements of the effectiveness of their products.

Where I would stand is that a sense of empowerment over what happens to you during labour need not come from hiring expensive and worthless kit from a large pharmaceutical company like Boots. The NCT classes, to their credit, do discuss the various techniques that women find helpful, from breathing to relaxation methods, attention to position and roles of partners.

Whilst these methods may well too have large limitations, at least they are honest and claim little more than a sense of control. For that reason, I think we will be saving our £30 and spending it on some nice candles and crystals.

25 Comments on Boots Maternity TENS Machines. Do they work?

  1. I had a tens machine when I was in labour, it didn’t come out of the box…I had a couple of contractions asked for epidural which didn’t work so then had a spinal block which did.
    I also did NCT classes and they were very “anti intervention” and pro natural birth but my 4yr old son would not have survived had I not had intervention from the midwife and eventually a C section.

    Best of luck….

  2. My personal highlights from nct classes were
    – the repeated statements that the cottage hospital was a much safer place to give birth than the local maternity ward. Ignoring the fact that if it all went wrong you would have to endure a 30 minute ambulance ride to medical expertise.

    However, this was topped by the demonstration, with around 20 playmobil figures, of how public a ceasarean was in comparison to given birth in the comfort of your own home with your personal, friendly midwife.

    • Asdf: the ‘playmobil’ demonstration is a standard of NCT classes. Aim is to prepare the one in four class members who will end up with a section, to explain who the various personnel are likely to be… there is either no time or inclination for introductions in real life. It’s a good exercise – and of course a section is different from a home birth, but that’s not the purpose of the demo.

      A cottage hospital? Not many of them about these days, but those that do exist normally have excellent maternity stats with fewer interventions and iatrogenic problems, and greater maternal satisfaction, than district general hospital maternity units. It’s something people can check for themselves, anyway, as these figures are in the public domain, alongside factors such as the proportion of high risk pregnancies booked at each (which will skew the stats).

  3. We were feeling very poor when the registration form for the NCT classes came through and decided not to fork out the £150 plus (at least) so went to the NHS classes instead. They were free imformative. I would say fairly empowering and happily free of woo.

    When one the midwives was asked about Tens machines she said not to waste your money.

    I had an emergancy c section and quite frankly as far as I was concerned the more the merrier if it meant the safe delivery of my baby. Mind you I was off my tits on Gas and Air so didn’t give a monkeys.

    Great stuff gas and air it didnt stop me from feeling the pain when the contractions got really bad but it stopped me from feeling miserable about them. I had an epidural in the end which worked well but I did have post natal headaches cos of it I think.

  4. My experience is similar to the first comment. I was supplied with a TENS machine (this was abroad) but it never came out of the box. I think it “worked” in the way that doing balance poses in yoga is easier if I am standing near a wall. I never actually touch the wall, but knowing the wall is there helps me to balance. In the same way, believing that the possibility for pain relief was there (I didn’t know at the time it had such a poor foundation in science) made it easier to tolerate the pain. In the end it was a relatively straightforward, fast labour and I didn’t need any pain relief.

  5. The only use I’d have found for a candle was throwing it at somebody.

    I never came across TENs rental here in Italy, although it got rave reviews by the woman running my birth classes, but the cables would have come in handy to strangle the doctor with when she cheerfully announced that the Sesto SG hospital operated a “no pain relief” policy, it all had to be “natural”, like it or lump it, right after I lost the ability to be able to walk out and go to another hospital due to my legs buckling with the the pain.

    I ended up with a c-sec because after 20 hours of induced, agonizing, unmediated labour I was a limp rag and couldn’t have pushed out a marble let along a 4 kilo baby. That now nine year old baby is an only child for a reason.

    For the lay woman trawling through and sorting the wheat from the chaff in terms of studies and results is an huge task many don’t feel equipped to take on. So we get fed the interpretation of interested parties. Since the “natural labour and birth” movement has spawned an industry based on what to me looks like a tarted up, god-lite, new age version of “women must suffer in childbirth cos of what Eve did”, I’d love it if you did a piece (or ten) on the studies relating to “what is safe for baby” with regards to various medical/surgical interventions and the efficacy of the alternatives. Women are vulnerable, particularly during their first pregnancy and they end up believing that any “non natural” intervention is playing Russian roulette with their baby’s well being, given what I suspect to be a statistical slant offered by many birth classes. From my own experience I think hospitals may well be under PR pressure to try to get their epidural/c-sec figures down and place greater emphasis on that end rather than on the needs of the individual women in front of them.

    It would be nice to see the conclusions of somebody equipped to arrive at them, who doesn’t have a dog in the race, but is speaking as a “service user”.

  6. Whilst I doubt TENS ability to help with labour pains I do use one every day. I was attacked 30 years ago and left with internal injuries that cause me much pain to this day which fluctuates from a dull ache to excrutiating agony that can leave me faint, sick and sweating. I would recommend that anyone with long term pain like mine seeks medical help to find the cause of the problem. I have had all the help my Doctor can give except for major surgery which I am not willing to undergo. The only alternative is for me to be permanently on painkillers. My TENS machine has enabled me to override the bouts of pain for the last 8 years. So while I agree with most of your (as usual) excellent post I would say that TENs machines have their uses : )

  7. TENS lives on because no-one can design a decent sham control for it – you definitely know when it’s switched on. So then we see the usual marginal effects on the pro-side of the line which most likely represent lack of subject blinding but are interpreted as representing a small but important effect. Wait, haven’t we heard this before elsewhere?

  8. The number one priority is a health mother and healthy child. A “good birth” or “Natural labour and birth” is much less important. Don’t let it get in the way of protecting mother and child. Still births, injured babies, and dead mothers still happen in modern medical care, so do not let the “good birth” / “good start” mantra increase the risk of a terrible outcome. You can bond fine with the baby even after major interventions. Personally my wife’s only post-natal depression was after the baby who had no troubles, not after the ones who were in hospital separately for several weeks.

    As for TENS, I know others who like it for chronic pain like madgestar, but on the midwife’s advice, we never unwrapped it for the labour my wife had – it was reputed to be good for early labour only.

    Possibly useful labour advice: Your wife should not keep talking on the phone during a contraction (just drop the phone and pick it up when its over) – you’ll get poor decisions if she tries to.

  9. “Obviously, people may not hand over hard cash if they know that all they are going to get is an illusory sense that pain has been reduced rather than a real one.”

    I think this goes to the heart of what we mean by placebo effect and tends to make my head hurt if I try to think about it too hard.

    Illusory pain relief and real pain relief are not the same thing. Discuss.

    I think the distinction, you comment on, between semi-objective scoring at the time of pain and the level of efficacy inferred by patients after the event is fascinating.

    Anecdote alert: Mrs Monkey used a TENS machine in pregnancy. It seemed to help with the pains of late pregnancy but appeared fairly irrelevant in the context of actual labour.

    Because of the highly subjective nature of pain, having a device that requires fiddly application and management must reasonably have an effect on perceived pain simply because it distracts the patient, but only if it’s the kind of pain from which you can be distracted.

    • Illusory pain relief? My take on these results is that TENS does not alter the perception of pain, but users are led to believe their pain will have been worse if they did not use it. As such, its pretty much a fraud.

      • An interesting perspective on these non-significant, non-blindable effects, and one that matches many people’s experiences for various sham treatments.

        “users are led to believe their [condition] will have been worse if they did not use it” also probably applies to quite a few of the ineffective Over The Counter pharmacy medicines as well as the non-pharmaceutical quackery.

  10. It is very easy to test the efficacy of this particular machine, my proposed tests should be mandatory for all who sell/rent/make/distribute or design these contraptions.

    Let them be stripped to the waist, let them apply as many of their machines to wherever they feel it best.Let them then be thoroughly whipped. If the machine works it will be painless, if it does not let them admit it for the whipping to stop.

    • YMMD. 🙂

      More seriously, though, since the TENS devices do not only claim “electricity relieves pain” but “electricity in the right places does so”, one could in fact blind a study if one wanted:

      In the control group, simply stick the pads to “meaningless” places (and tell the patients that this makes it especially effective). In the treatment group, do all according to the manual.

      Compare the results.

      Throw the thing away.


  11. I was given a TENS machine by the hospital as due to complications I was in labour for a very long time. In all, I’d say I was on it for maybe 36 hours. I’d say they work by distracting you from the pain – like the effect of rubbing your back when it’s sore.
    I was relieved when I finall said goodbye to the thing. I reached a stage where the TENS was causing me more pain!
    After a few more hours without the TENS I was finally admitted to the delivery suite and given an epidural – now that works!!

  12. “Electrocution as a cure” – electrocution is _killing_ by electric shock, not simply administration of shocks. Nobody ever advocated therapeutic electrocution.

    Girls like pedants.

  13. Hi
    I would say that TENs did not provide any pain relief (as such) but it works in the sense that it is a good distraction and gives you the feeling that you can do something to help yourself. As women who enter labour feeling confident have been shown to have better outcomes than those with a negative outlook, this is not to be underestimated.
    I can’t say that most people who use Gas & Air would say that it actually relieves pain either, not pethidine for that matter. But it doesn’t stop them being doled out in hospital without many lower risk alternatives. Anyone seen an RCT on the benefits of entenox?

  14. I am dissapointed to see so much negativity about TENS here. I had a terribly painful shoulder condition with pain radiating down my arm. The TENS definitely helped me a lot. It has also helped my wife with a number of painful conditions.

    For one thing, the pattern produced by the TENS distracts the mind from the pain of the affliction. If you have knee pain for example, the pulses above and below the pain area distract the brain from the real pain.

    You can leave a TENS on for a long time, and its my experience that after a while the TENS will reduce the perception of pain. Sometimes stopping a pain cycle is enough to bring relief and even an end to the pain of the affliction.

    This has helped me with numerous serious pain conditions and I recommend it all the time to others and they too have had great results. If you are in pain, try it for a few days.

  15. “You can leave a TENS on for a long time, and its my experience that after a while the TENS will reduce the perception of pain.”

    That is precisely what Andy’s post was about. The TENS gives you a feeling of control and the distraction that it provides gives it a certain plausibility. However, “I used it and eventually the pain went away” does not prove at all that the TENS *caused* or even *helped* the pain to go away.

    It is a typically human thing to ascribe expected results to some specific intervention, even though there may not be good evidence for that.


  16. I am mildly disappointed at all the negativity expressed here about TENS machines. My wife has complained for several years of serious pain in her shoulder, so bad that she was frequently unable to sleep without fairly heavy doses of painkiller. Having exhausted all other remedies I bought a TENS machine. She was very sceptical and for some weeks refused to have anything to do with it. Eventually she agreed to try it for a few minutes. Gradually her confidence in the machine strengthened and she began to use it regularly at night with it running gently for hours whilst she slept. She used it nearly every night for about a month or six weeks then her need for it gradually reduced. She has been entirely pain free for about 6 months. For the time being I’d say she is cured. It was without question the Tens machine that did the job, for she has been taking no other medication, her routine has not changed nor have we moved house.

  17. Cochrane review: Pain management for women in labour: an overview of
    systematic reviews (Review) says:

    There is insufficient evidence to make judgements on whether or not hypnosis, biofeedback, sterile water injection, aromatherapy, TENS, or parenteral opioids are more effective than placebo or other interventions for pain management in labour. In comparison with other opioids more women receiving pethidine experienced adverse effects including drowsiness and nausea.

    Authors’ conclusions
    Most methods of non-pharmacological pain management are non-invasive and appear to be safe for mother and baby, however, their efficacy is unclear, due to limited high quality evidence. In many reviews, only one or two trials provided outcome data for analysis and the overall methodological quality of the trials was low. High quality trials are needed.
    There is more evidence to support the efficacy of pharmacological methods, but these have more adverse effects. Thus, epidural analgesia provides effective pain relief but at the cost of increased instrumental vaginal birth.
    It remains important to tailor methods used to each woman’s wishes, needs and circumstances, such as anticipated duration of labour, the infant’s condition, and any augmentation or induction of labour.
    A major challenge in compiling this overview, and the individual systematic reviews on which it is based, has been the variation in use of different process and outcome measures in different trials, particularly assessment of pain and its relief, and effects on the neonate after birth. This made it difficult to pool results from otherwise similar studies, and to derive conclusions from the totality of evidence.
    Other important outcomes have simply not been assessed in trials; thus, despite concerns for 30 years or more about the effects of maternal opioid administration during labour on subsequent neonatal behaviour and its influence on breastfeeding, only two out of 57 trials of opioids reported breastfeeding as an outcome. We therefore strongly recommend that the outcome measures, agreed through wide consultation for this project, are used in all future trials of methods of pain management.”

    There is a huge amount of research on TENS, with many positive results. The problem is that there is no unbiased way of evaluating these results. Reviews of RCTs attempt to do this by looking at methodology and only giving weight to properly designed trials. However this can lead to errors as well . See : “Methodological quality in randomised controlled trials of transcutaneous electric nerve stimulation for pain: Low fidelity may explain negative findings Bennet et al .PAIN 152 (2011) 1226–1232″ This reports that the majority of RCTs on TENS included in reviews had fundamental flaws in understanding the physiology of the effects they were trying to measure.

    Conclusion: its difficult to choose between positive and negative results of RCTs without a good understanding of how the trials were carried out. Almost all reviews of RCTs for non-pharmaceutical treatments end up by saying ” more high quality research is needed”. This does not mean that the treatment is ineffective, just that the resources of the pharmaceutical industry have not been invested in demonstrating it.

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