Samphire Neuroscience is building a brain stimulating wearable for period pain

It’s a horrible truth that many women simply endure period pain every month — perhaps relying on painkillers or a hot water bottle to relieve stomach cramps. For others, menstrual pain can be inescapably debilitating — to the point where they have to stay in bed for days each month and wait the pain out, as over-the-counter painkillers don’t provide relief.

People who menstruate may also suffer from PMS, the mood swings and emotional sensitivity that can occur in the days leading up to a period. Or from an even more severe mood disorder, PMDD. Beyond the usual advice of trying to have a healthy lifestyle, treatment options for mood swings are pretty limited — and serious sufferers may feel they have no choice but to go on hormonal birth control. (If, indeed they can, given there can be medical risks associated with taking the pill.)

What if there was a drug-free and effective way to manage both menstrual pain and mood disorders? One that doesn’t involve popping any pills, let alone resorting to the irreversible treatments sometimes offered for extremely severe pain, such as the surgical removal of a woman’s womb.

UK medtech startup Samphire Neuroscience is taking an alternative and, it claims “science-backed” approach, to tackling these age-old women’s health issues. It’s developed a head-mounted “therapeutic” wearable that applies a non-invasive, low electrical current type of brain stimulation, called tDCS (transcranial direct current stimulation). The wearable targets regions of the brain associated with pain perception and mood regulation to, essentially, reduce sensitivity and block pain signals — applying (non-pharmaceutical) neuromodulation as a targeted treatment for period pain and PMS.

How does neurostimulation actually work? The theory behind tDCS is that applying a constant electrical current increases “neuroplasticity”, or the brain’s ability to change and adapt by forming and reorganising synaptic connections. In this women’s health use case, Samphire contends there’s a clear and linear link between hormonal levels and brain “structure and activity” — meaning the menstrual cycle enacts changes in the brain, which can affect “mood, energy, sensitivity and more”. It says this effect can be especially pronounced during the luteal phase, before a woman’s period starts, when hormone levels can be changing a lot — so its brain stimulation device is also designed to be used during this phase of the woman’s cycle.

The battery-operated wearable, which it’s calling Nettle, resembles a chunky black headband. The user wears it for treatment sessions over a period of several days (five) before their period starts — which the startup says will alleviate pain and mood symptoms associated with (and around) their next bleed. The device works by targeting electrical current at two regions of the brain Samphire says are associated with menstrual pain and PMS, respectively: Namely, the motor cortex, which it says plays a role in pain perception, and the prefrontal cortex which is associated with mood regulation. So it’s designed to address both physical and psychological symptoms.

While brain stimulation has been investigated as an experimental medical treatment for centuries — it’s fair to say with varying degrees of success — the technology has become more established as a treatment for issues like chronic pain. In more recent decades there has also been a surge of interest, and some evidence, in tDCS’ potential for treating depression especially.

Here Samphire points, by way of validated commercial example, to a fellow neuro tech UK startup as a bit of a pioneer: Flow Neuroscience — which already sells a head-mounted device it claims is clinically proven as more effective for treating depression than antidepressants. But where Flow’s product focuses on using neurostimulation to treat low mood regardless of the person’s sex, Nettle is designed specifically for women, and targets both mood symptoms and period pain.

This combination is important as Samphire argues these two symptoms — sensitive mood and pain — are intertwined when it comes to determining how women feel on their period.

Hitting the right spots

“One thing that we were surprised by is usually [neurostimulation] technology is known, in other conditions, to be highly effective but the reduction that we have seen in pain within a single period’s use is actually very unusual. It’s extremely high,” co-founder and CEO Emilé Radytė tells TechCrunch, noting too that the startup’s technology has been tested on a sample that’s disproportionately female vs the industry. “So it seems that, for women, if you stimulate in the right phase — which in our case is right before your period — that actually really matters. Because instead of needing to stimulate every single day, there seems to be some connection between the way that we perceive pain in different [menstrual] phases.”

“Historically, when people tried to improve pain in fibromyalgia using a similar technology — and there’s early promising evidence of that but not yet that much — they struggled to see a huge reduction in pain. Our explanation [for getting opposite results] is that because we also stimulate the mood bit, so essentially, we improve your mood and therefore we improve your way of managing pain in the first place — and then on when on top of that we reduce the pain — that actually makes the biggest difference,” she suggests. 

“That makes even our product design quite differentiated — and that we almost figured out by chance, down the line. But it obviously leans into the fact that menstruation is both a physical and physiological but also an emotional and kind of psychological process. And [the high pain reduction we’ve seen derives from] being able to stimulate both — improving mood improves your ability to manage pain; and when you’re not in pain, you’re able to better manage your mood — and I think that bi-directionality seems pretty straightforward but it seems to be in our data as well, which is cool.”

Radytė is on familiar ground here, bringing a background in neuroscience to attack the problem. She studied at Harvard and Oxford, where she obtained a PhD in neuropsychiatry — which included researching depression treatments (including brain stimulation) and looking at why treatments can work differently for different people.

Her co-founder, Alex Cook, meanwhile, trained as an IP lawyer and has prior startup experience leading a product team — both obviously useful skills to have on tap if you’re commercializing academic research that involves proprietary hardware.

Samphire is also drawing on work done by two research labs focused on brain stimulation and women’s health — one in Australia and one in Brazil — which Radytė explains had looked, separately, at menstrual pain and PMDD, and found strong effects for using this type of technology in both cases. The startup’s idea for advancing their work was to combine the targeted treatments and see if it would compound the benefits.

They’ve been backed, since starting work on the problem back in late 2021, by a number of early investors which have contributed to a $2.3 million pre-seed round (and the startup’s first priced equity round). Investors include SOSV, Firstpick, Afterwork, Seaside, Ayuh, and CVX Ventures. A number of angels also chipped in, including Russell Buckley, ex-chairman of Touch Surgery, founder of Kindred Capital; Dr Pamela Walker, founder of Thena Capital; and Rowena Ironside, founder of Women on Boards UK.

“There’s often a misconception that pain is always a physical symptom. But to me, it’s very much a mental symptom. So it does make sense to treat it in the brain,” argues Radytė, delving more into the theory underpinning Samphire’s approach. “Because — with painkillers — you always need to take more painkillers, the more pain you have. Because painkillers are trying to block the receptors that precede the pain. Whereas if you’ve blocked pain sensitivity altogether, it actually doesn’t matter how strong your pain is. That means that we can handle much higher extremes of pain as well — because we’ve changed the perception of the pain in the first place.”

“To me brain stimulation devices are the future,” she adds. “Because for any long term condition… no one wants to constantly take medication. So if we can change that status quo — where women can be dependent on other things [than drugs] to manage their cognitive and physical symptoms — then that has to be the future. Especially because women need to live with these conditions for all of their lives.”

As femtech startups often do, Radytė points to how the bulk of medical research has failed to pay proper attention to sex difference, including — in this period-focused context — not considering how hormonal changes in women could lead to distinct responses to treatments. This has created a situation where women’s health needs are under-researched and even overlooked. And where ‘standard’ treatments women get offered are often suboptimal, since fewer innovations have been developed that cater to them. Hence Samphire Neuroscience is on a mission to close this innovation gap. The Nettle headband is intended as the first in a series of products targeting women’s health, with future therapeutics set to focus on female insomnia and the perimenopause.

Its first wearable is not yet available to buy. Indeed, the Nettle headband won’t be available unless/until it obtains a CE mark from European medical device regulators — which Radytė says it’s hoping to gain later this year. (RRP will be €409/£359/$449, per an FAQ on its website.)

They intend to sell the device direct to consumers and via retailer partners. Per Radytė, research the startup conducted into women’s attitudes to traditional healthcare providers suggest they continue to have very low trust in doctors to handle these sorts of sex-specific health issues — and people more likely to trust a recommendation from a friend. This is why they didn’t want to gate access to the product behind a prescription, so no doctor’s sign off is needed to buy it. But the team is hoping the hardware will be reimbursable, via health insurers, in future. (She also says the startup is working with doctors, and has clinical advisors, as it continues to develop the product. And intends to sell Nettle through hospitals it’s collaborating with too.)

Clinical trial

So what proof can it show that Nettle really does work? Samphire has undertaken a clinical trial that Radytė says shows “really promising results” for treating period pain and PMS. The study underpins its EU application for medical device certification — where it’s seeking a Class 2A CE marking. The regulatory process entails comparing Nettle’s efficacy for pain relief vs the performance of painkillers, while for mood symptoms it’s compared to antidepressants. So the assessment is comparative vs existing treatment options.

“The actual indications for use of our device will be for managing pain associated with menstruation and managing mood symptoms associated with premenstrual syndrome,” she notes. “So, specifically, what we claim is an improvement in low mood in the pre-menstrual period. But we expect to extend that, over time, to also things like irritability and mood swings. But those are just a little bit difficult to test in the way that the EU likes them.”

Radytė says the clinical trial it conducted last year as part of the certification application involved collecting pain and mood scores from around 50 people across a menstrual cycle when they did not use its device; and again across a cycle when they used the wearable to deliver brain stimulation for five days before their period (or they were given a sham device which, initially, mimics the sensation of electrical current but does not administer the treatment to correct for any placebo effect).

The study also collected scores for the participants’ pain and mood on the subsequent cycle after they had stopped using the headband to see whether there were any lingering effects.

“We expect the best kind of use will come out of our device if you use it for at least three months. But here we just wanted to show that even within a very quick amount of time you can see a difference. And what we showed is that, on average, people’s pain decreased by 52% when they were using the active device — and it kept decreasing the month afterwards,” she says, adding: “Those who had the active intervention [i.e. not the sham headband] actually had a much lighter period the following month as well.”

While around 50 clinical trial participants might sound low, Radytė argues the size of the trial is appropriate for neurostimulation technology studies — and statistically significant. “Because there’s historical studies on this technology, we could tell how many people you need in order to find statistical significance if there is some and that’s essentially how you define sample sizes,” she explains, adding: “In the field of brain stimulation, everything above 20 is a good sample size — which is why we went for the number we did.”

(For the record, Flow Neuroscience’s rival device for depression bases its claims of clinical efficacy on a double blinded placebo controlled clinical trial which it said showed the product to be twice as effective as antidepressants on a study involving around 170 participants.)

“What is new, and I think what is really interesting about a product like ours, is we are spending quite a bit of time educating the regulators about where really to put neurotechnology for women’s health,” Radytė continues. “Because at the moment we are categorized very much in the field of neurotechnology and very much in that kind of lump of regulation which is extremely high [in terms of the level of proof required to get certification as a medical device].

“But if you look at the state of the art for women [i.e. for treating period pain and mood] it’s extremely low. And that overlap hasn’t yet been categorized well — which is why we’re almost pushed through much higher regulatory and clinical burdens because we’re evaluated in the technical product category, rather than a kind of public health need category.”

While the UK is no longer in the EU, as a consequence of Brexit, the country has not rolled out its own alternative system for regulating medical devices. So Samphire expects, once it has obtained the bloc’s CE mark, that it won’t have to repeat the whole application in order to access the UK market — but will instead be able to notify the equivalent national body (the UK’s MHRA) and get permission to sell Nettle.

However, the usual complexities of applying and obtaining clearance from medical regulators apply elsewhere. So Samphire will be focused on selling its wearable across Europe in the first instance, producing an initial run of 1,000 devices to test the water. It does have plans to target the US market in the future — estimating it’s 1.5-2 years away from a US launch. (It plans to apply for a “breakthrough device” designation from the FDA — which will require it to run fresh clinical trials in the US to meet the regulator’s bar, per Radytė.)

While brain stimulation might sound a pretty drastic treatment for period pain, safety concerns shouldn’t cause too much pause for thought given the device will only be sold when/if it has satisfied the EU regulator that it doesn’t pose any risk of harm. Asked about safety Radytė also points back to what she says is over 30 years of research into similar technologies, primarily used to treat psychiatric disorders, adding: “There has never been a serious adverse event reported.”

What about possible side effects of applying low current neurostimulation? “Mild” side-effects are very common, per Radytė — including itching and tingling the first time treatment is applied (related to the person’s skin reacting to the current). But she suggests most people get accustomed to the treatment and any skin sensitivity goes away. A more serious side-effect she mentions is that some women may get what she calls “transient migraines” — transient because she says they “seem to always dissipate within 30 minutes”.

Whether the risk of a fairly brief migraine is a good trade off for the chance of having a better period will depend on a woman’s own experience of their menstrual cycle and any symptoms they regularly suffer. For some, the risk of a short headache once a month might sound a lot more manageable than what they usually have to go through. For others, a hot water bottle and bed rest might still be all they need.

Those who suffer the worst levels of period pain should be aware that Nettle’s website stipulates the device is not intended as a treatment for people who’ve had a specific diagnosis of endometriosis — a condition that can cause extremely painful periods — but the startup still suggests the device may help alleviate some of the pain they experience.

Product design & fit

Some practical considerations: As Nettle is worn on the head it will typically have to function through hair. The user needs to spray a saline solution onto conductive sponges on the underside of the band to ensure the current flows properly during the 20 minute treatment session.

However — currently — it does not work if the users has Afro hair that’s worn in “thick braids”, according to Radytė. But she says it will work through loosely braided or finely braided Afro hair. (She also notes that well over half (67%) of its sample of testers for the clinical trial were non-white, adding: “That was really important to us from a diversity of hair perspective and hair product perspective.”)

The headband itself is designed to be extremely simple to put on and use, to avoid the risk of a person incorrectly applying the treatment. So it has no wires and just a single button to activate the neurostimulation treatment.  While the shape of the band is designed to target the correct brain regions, regardless of a person’s head size and shape.

Radytė says the team spent a long time on the hardware design — trying to achieve someting that looks pretty enough the user could wear the band to work or out and about without feeling self conscious. So while it’s fairly nondescript and minimal looking, that was really the goal. In the field of neuro tech making a device that doesn’t stick out and look ugly is innovative in and of itself, she argues.

Samphire is also developing an app to work with the wearable — powering notifications to remind the user when it’s time to apply their treatment. The app will also include a period tracking function and offer users the ability to participate in future research projects the startup wants to undertake out to boost understanding of period issues and “give back the community”, as she puts it.

One interesting question will be the scale of demand for Samphire’s product. Therapeutic wearables are still fairly novel (tracking wearables are far more common). And while, across Europe, millions of women are of menstruating age and many of them will suffer some sort of period pain, it’s less clear what proportion regularly experience periods so horribly miserable that they’d be willing to invest this much in a treatment device.

Samphire cites stats suggesting 90% of women suffer some form of PMS (acute to mild) and 91% suffer pain (period cramps or dysmenorrhea) during menstruation itself. It also notes endometriosis affects 10% of women globally and PMDD between 5% and 8%. But, again, these sort of general statistics don’t provide a detailed picture of how much pain and misery women routinely suffer through — and whether, therefore, there might be mass or niche demand for a period-pain wearable.

If the startup gains regulatory certification and is able to prove the worth of its approach, there could be potential for scaling sales via a b2b2c model, though. As well as getting health insurers to reimburse the product, it could — for example — pitch employers on subsidizing Nettle to offer female employees as a support measure which could also help reduce the need for staff to take menstrual sick days.