Detailed guides to painful problems, treatments & more

Zapping period pain: TENS for primary dysmenorrhea

 •  • by Paul Ingraham
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Weekly nuggets of pain science news and insight, usually 100-300 words, with the occasional longer post. The blog is the “director’s commentary” on the core content of a library of major articles and books about common painful problems and popular treatments. See the blog archives or updates for the whole site.

In this short post — 2-min read — I review a negative review of the Noha device for period pain … and the allegedly superior options.

I am a big fan of Dr. Jen Gunter’s work and her advocacy for science-based women’s health, and so I was bit worried when she posted about transcutaneous electrical nerve stimulation (TENS) — a topic I’ve written plenty about over the years. I was afraid she would give it more credit than it probably deserves. I did not want to be disillusioned about someone I greatly respect.

Result? Could be worse, could be better. 🙂

Dr. Gunter’s post is mainly a review of the “Noha” (made by Ovira), describing it as an “inferior” TENS unit priced to gouge women (the “pink tax,” gender-based price discrimination). “I HATE a bait and switch,” she writes. “And I HATE a pink tax even more. And I DESPISE people who take advantage of those with period pain.”

Amen! And so far, so good.

What is this “superior” TENS, though?

I’m a lot less comfortable with the implied claim that other TENS devices are actually “superior.”

However, I don’t have a uterus, and I have never looked at the evidence on TENS for dysmenorrhoea specifically. Maybe it’s different? Maybe TENS is a waste of time for practically everything else it has ever been used for, but manages to shine at this job?

I have my doubts, but I’m not dismissing it out of hand — such exceptions certainly exist. (For instance, there is a very specific physiological reason why NSAIDs are more effective for menstrual cramps than they are for a lot of other common painful problems: see The Science of Pain-Killers.)

Citation needed

Citation needed, obviously, and Dr. Gunter diligently cites a scientific review from a generally credible source (The Cochrane Collaboration). It concludes that TENS was “found to be effective for the treatment of dysmenorrhoea by a number of small trials.” Clearly good news on its face.

Unfortunately, she cited that review uncritically when there’s rather a lot to be critical of. Even the best reviews can have major issues. But this one is a classic example of a “garbage in, garbage out” review, without enough good data for a real conclusion. It’s also more than twenty years old.

Better citation needed

There’s almost no fresh evidence on treating painful periods with electricity — shocker — but what we have is exactly what any good cynic would expect. For example, a 2015 trial by Machado et al compared TENS to heat and placebo for dysmenorrhea in several dozen woman… and heat won. It was modestly better than TENS and placebo, which were both the same.

Nothing promising about that result. If TENS is powerful for periods, it sure has a funny way of showing it.

Stick with a nice heating pad

Even a cursory look at the details here show that there wasn’t enough evidence in 2002, and there’s still not enough today — but what we do have ranges from barely positive to clearly negative.

And then there’s the broader context: the abject failure of TENS to successfully treat any other painful condition.

My advice is to stick to ibuprofen and a nice heating pad. And if you still want to experiment with TENS, at least don’t pay the “pink tax.”