Wish you could make pain go away with the click of a button? A product promising to do just that is being advertised on television and it can be yours for a mere $160.

Ads for the Pain Erazor pen claim it offers drug-free pain relief through “the science of electro-analgesia”. “Say goodbye to the suffering you experience when pain or discomfort strikes,” boasts the marketing material. “Fast, affordable, convenient & extremely effective!” it trumpets.

Eliminating your aches and pains with no pills or costly visits to a doctor sounds appealing, even too good to be true.

What is it? The Pain Erazor website offers a less-than exhaustive explanation of how this pocket-sized device delivers results. It claims the pen works by exerting pressure on a quartz crystal, which produces a tiny electric charge. This, according to the website, stimulates the body’s endorphins to act as a natural pain killer.

It’s true when some solid materials are put under mechanical stress, they produce an electric charge, known as piezoelectricity. These materials include quartz crystals.

But how could that treat your tennis elbow or aching back?

Electric currents can be used for pain relief – a process called transcutaneous electrical nerve stimulation (TENS). This type of treatment uses a small, battery-operated device that’s connected to electrodes placed on the skin. The device delivers small electrical impulses to activate opioid receptors in the spinal cord and brainstem.

University of Otago clinical senior lecturer Dr Bronwyn Thompson says a TENS current essentially “confuses” the information being sent from nerves to the central nervous system (spinal cord and brain) to activate the natural pain relief the body can produce.

The jury’s still out on whether TENS is a reliable method of pain relief. A 2015 review by the well-respected Cochrane Collaboration concluded there’s still a lack of good quality evidence and more studies are needed.

Brand Developers, the company marketing the Pain Erazor, claims the analgesia it provides is similar to TENS but has a “more effective, longer-lasting pain killing effect than a regular TENS unit”. It also says it “has been tested and deemed safe and effective for both acute and chronic pain”.

However, there’s no trial data in the 116-page book that comes with the pen or on the company’s website, which instead features a testimonial by a motorcycle stuntman.

Evidence required Marketing of the Pain Erazor illustrates how little regulatory scrutiny these types of medical devices are given before being sold in New Zealand.

There’s no required pre-market assessment or approval process before a product hits shop shelves. The company supplying the product just has to register it on Medsafe’s online database, which isn’t open to the public. No studies have to be filed to support a product’s claims or prove its efficacy.

There’s no trial data in the 116-page book that comes with the pen.

Companies selling medical devices that claim to operate by inducing an electric force are required to tell customers in writing how much power the device puts out. This information wasn’t provided with the Pain Erazor we bought. Brand Developers initially refused to say how large the electric charge is, stating the information was “sensitive” intellectual property.

In 2015, the company was told to pull a TV ad for the pen after a complaint to the Advertising Standards Authority (ASA). The ASA decided the ad, which touted the pen as providing “fast, natural, effective relief for pain”, was misleading and the product claims hadn’t been adequately substantiated.

According to the ASA decision, the evidence Brand Developers submitted to support its pain claim was a literature review by a chiropractor. No double-blind, randomised clinical trials of the Pain Erazor were provided – the minimum we think could reasonably be expected to substantiate claims the product is “extremely effective”.

When we asked Brand Developers for evidence to back its claims, the company originally declined to provide any clinical studies. It then said it would only release the information if we signed a non-disclosure agreement. We declined to do so.

The report the company subsequently provided was an unpublished 2015 review by a Canadian chiropractor, which appears to be the same report provided to the ASA.