By proceeding, you agree to the storing of cookies on your device to enhance site navigation, analyse site usage, and assist in our marketing efforts. View our Privacy Policy for more information, or manage your preferences.

The power to transform your cycle lies in your brain

Nettle, the world's first medical-grade neuromodulation wearable for PMS and menstrual pain. Nettle reprograms how your brain perceives pain and mood symptoms.

The Future of Menstrual Care

Using advanced neurotechnology, Nettle improves your menstrual cycle health by transforming your brain’s neural networks. Experience results in one cycle, regain control over your life in three.

The world’s first medical-grade, drug and hormone-free solution for managing PMS and menstrual pain.

Non-invasively targets the most common and severe mood and pain symptoms at their source in the brain.

Backed by over 30 years of clinical research, outperforming traditional treatments in our trials.*

Built to fit into your routine with sessions for just 20 minutes a day, 5 days a month.

* At-home Treatment of Primary Dysmenorrhea using a Wearable IoT Neuromodulation Device: A Triple Blind, Randomised Sham-Controlled Trial). See the results here.

Get Nettle

Nettle is now live for pre-orders in the European Union and United Kingdom. All pre-orders ship in August. Early adopters get exclusive perks.

“What if there was a drug-free and effective way to manage both menstrual pain and mood disorders?”


Throughout our communications, we use the word women to include all people experiencing menstrual-related issues, including but not limited to all people assigned female at birth.


Nettle uses brain stimulation to target brain regions responsible for pain perception and mood regulation.

Its underlying technology has been clinically validated in managing pain, depression, anxiety, cognitive function and performance through over 30 years of research.

What does Nettle do?

Modulates neuronal excitability

Neuronal excitability is the ability of brain cells (neurons) to respond to stimuli and convert these into electrical impulses, crucial for everything from motor responses to complex thinking and memory. Proper regulation of neuronal excitability is essential for brain health. Abnormal levels can lead to neurological disorders, such as depression, where certain brain areas become underactive. Nettle employs low-current electrical pulses to adjust neuronal excitability, helping adjust these imbalances.

Rebalances activity in your brain

During the luteal phase of your menstrual cycle, rising progesterone levels lead to changes in brain activity. These hormonal fluctuations are associated with alterations in mood, increased irritability, and cognitive shifts. Targeted brain stimulation, particularly applied to the dorsolateral prefrontal cortex (DLPFC), has been shown to mitigate these changes by normalising brain activity to levels observed during the pre-luteal phase.

Regenerates neural pathways

By applying a low-intensity electrical current to the brain, Nettle enhances neuroplasticity—the brain's ability to form and reorganize synaptic connections. This promotion of neuroplasticity ensures that Nettle's effects are lasting, leading to improvements in the brain's processing of pain and mood. These improvements can yield long-term benefits and reduce reliance on medications.

By targeting the brain, Nettle reprograms how you perceive pain and regulate mood.

After just one month’s use, our clinical trial users reported:

Reduction in menstrual pain

The average reduction in menstrual pain was 53%. This decrease continued over time, suggesting that the most significant reduction could be expected after 3 months of consistent use. Remarkably, over 44% of women reported minimal period pain (rated under 2 out of 10) after just one month of using Nettle. For comparison, painkillers typically only reduce pain by 45-53% on average¹, and it's estimated that at least 18% of women obtain no relief from NSAIDs².

Improvements in low mood

During the PMS period, the average symptoms of low mood improved by 34%. Impressively, 100% of users with extremely severe low mood symptoms (PANAS score above 25) reported a shift to moderate or mild symptoms after just one month of using Nettle. Furthermore, the relief from low mood symptoms extended for an additional month after discontinuation of Nettle, indicating potential long-term improvements with continued use.

Boosts in functionality

The average functionality, or fitness status, improved by 11%. This improvement is primarily attributed to reductions in pain and anxiety, as well as enhancements in mood, which collectively lead to increased activity levels. These benefits were directly associated with the use of Nettle and tended to diminish during the follow-up period, suggesting they are not directly brain-based effects but rather secondary effects of improvements in overall brain health and plasticity.

What parts of the brain influence PMS and pain symptoms?


Responsible for emotional regulation

Nettle specifically targets the dorsolateral prefrontal cortex (DLPFC), a region crucial for regulating emotions and cognitive functions. It plays a critical role in modulating responses to emotional stimuli and stress, essential for maintaining emotional stability. In individuals suffering from PMS, the DLPFC may be underactive or functioning suboptimally. By targeting and supporting this area, Nettle helps regulate the intense emotional responses often experienced by those with PMS.


Plays a role in pain perception

The motor cortex, specifically the primary motor cortex (M1), plays a role in the modulation of chronic pain, by indirectly modulating the activity of the posterior insula. Studies suggest that disruptions in the motor cortex can contribute to central sensitisation, a condition where the central nervous system is in a heightened state of reactivity, lowering the pain-perception threshold. By stimulating the motor cortex, Nettle can recalibrate the neural pathways that play a role in regulating the perception of chronic pain. This stimulation has shown to increase the pain-perception threshold.


Why should you try brain stimulation?

Brain stimulation for menstrual symptom management offers a non-invasive, drug-free alternative that directly targets the neural pathways involved in pain and mood regulation. This approach can significantly reduce symptoms like cramps and mood swings, improving quality of life without the side effects associated with traditional medications.

Non-invasive and natural

The brain stimulation we employ provides a natural, non-invasive means of targeting pain and mood symptoms via improving brain function and plasticity in relevant regions. Through gentle modulation of neural activity using low-current electrical pulses, which is the neuron’s natural energy, it optimises brain health, and in turn cycle health, without the need for medication.

Zero severe side effects

tDCS has a track record of zero severe side effects historically, due to its non-invasive nature. Some mild side effects are occasionally reported, such as tingling and itching (usually just during the first use) and, rarely, transient headaches and nausea (which subside within 15-30 minutes). This safety focus is crucial, particularly for women who have been notoriously prescribed medications with adverse effects.

Targeted relief

Through precision design, brain stimulation devices can target specific brain regions associated with various mental and physical symptoms, while leaving the rest of the brain and body untouched. In doing so, it addresses symptoms directly at their source, enabling a more efficient and effective treatment process.

Is Nettle for me?

Take our 5-minute eligibility questionnaire to assess if Nettle is right for you.

Your journey is supported by a neuroscience-backed app.

Nettle is managed through the Samphire Neuroscience mobile app, which syncs with your health data for a personalised experience. The app will offer cycle tracking and symptom logging features as well as neuroscientific content to support your journey toward a healthier cycle-brain connection.


Built on verified science

Nettle was built on over 30 years of research in the fields of chronic pain and depression management. Have a look at some of the key papers that validate our technology.

Transcranial direct current stimulation to reduce chronic pelvic pain in endometriosis: Phase II Randomized Controlled Clinical Trial

S Mechsner, et al., Pain Medicine (March, 2023).

Safety of transcranial Direct Current Stimulation: Evidence Based Update 2016

M Bikson, et al., Brain Stimulation ( 2016 ).

Development and testing of a novel IoT consumer tDCS device for the treatment of primary dysmenorrhea

E Radyte, et al., Brain Stimulation Journal (January, 2023).

Depression, anxiety, stress, and dysmenorrhea: a protocol for a systematic review

AH Pakpour et al., Systematic Reviews (March, 2020).

Altered cognitive control network mediates the association between long-term pain and anxiety symptoms in primary dysmenorrhea

Z Yu et al., NeuroReport (January, 2024).

Premenstrual dysphoric disorder and changes in frontal alpha asymmetry

E Baehr et al., International Journal of Psychophysiology (2004).

Modelling and Preliminary Clinical Validation of Home-based Menstrual Neuromodulation Therapy

E Radytė et al., Preprint (February, 2024)

Evidence-Based Guidelines and Secondary Meta-Analysis for the Use of Transcranial Direct Current Stimulation in Neurological and Psychiatric Disorders

F Fregni, et al., International Journal of Neuropsychopharmacology ( April, 2021 )

Effects of Transcranial Direct Current Stimulation for Treatment of Primary Dysmenorrhea: Preliminary Results of a Randomized Sham-Controlled Trial

R Pegado, et al., Pain Medicine (December, 2020)

Modulating Anxiety and Functional Capacity with Anodal tDCS Over the Left Dorsolateral Prefrontal Cortex in Primary Dysmenorrhea

L Dutra et al, International Journal of Women's Health (2020)

Our scientific experts

Dr. Sanjula Dhillon Singh

Neurosurgeon focused on global public health. Also the founder of the podcast called ‘Science with Sanjula’ where she interviews world-leading scientists about big issues in global healthcare. She is helping Samphire translate our science into public impact.

Professor Maria Theresa Micussi
Women’s Health Researcher

Researcher from Universidade Federal do Rio Grande do Norte focused on neglected women's health conditions. Responsible for running Samphire's clinical trials.

Professor Rodrigo Pegado
Chronic Pain Expert

World-leading chronic pain researcher from Universidade Federal do Rio Grande do Norte. He was the first person in the world to publish a paper on the topic of tDCS to treat pain in dysmenorrhea (menstrual pain).

Dr. Marie Christine Nizzi
Psychologist and Researcher

Pyschologist and world-leading researcher on innovative clinical interventions. Currently the president of Harvard Alumni for Mental Health and is responsible for developing Samphire's cognitive science-based interventions.

Professor David Silbersweig
Professor of Neuropsychiatry

Professor of Neuropsychiatry at Harvard and global PMDD neuroanatomy expert. He worked on one of the first pieces of research that showed that PMDD is a neurobiological condition, which laid the foundation for PMDD being recognised by the International Classification of Diseases.

Dr. Shazia Malik
Chief Medical Advisor

A highly qualified and experienced Consultant Obstetrician and Gynaecologist, with subspecialty accreditation in Reproductive Medicine and Surgery. She brings invaluable expertise in chronic gynaecological conditions like endometriosis and PCOS, and is supporting our clinical efforts to advance medical research in the UK.


If you have a question about Nettle or it’s launch, and we haven’t answered it here on our main FAQ page, please don’t hesitate to get in touch.

Are there any contraindications?

There are important contraindications that apply to using Nettle. If any of the below contraindications apply to you, you should not use Nettle.

  • Persons who are under 18 years old.
  • Persons with a history of seizures or epilepsy.
  • Persons who are pregnant or may be pregnant.
  • Persons experiencing active suicidal thoughts.
  • Persons with a pre-existing neurological or neuropsychiatric condition.
  • Persons with a lesion, tumour or other defect in your skull, cranium or brain.
  • Persons with an implant inside their skull, cochlear implant or implanted hearing aid.
  • Persons with implanted medical devices, such as a cardiac pacemaker or neurostimulation devices, such as spinal cord stimulators, vagal nerve stimulators, auricular stimulators, or deep-brain stimulating electrodes.

If you are unsure about whether any contraindications apply to you, you must consult with your physician before continuing, especially if you are under the care of a physician for any conditions related to the central nervous system (e.g. neurology, psychiatry).

Have you tested Nettle on women of colour?

Yes! 47.1% of participants in our clinical trials self-identified as women of colour, 67.6% of them had wavy, curly or coily hair, and trial participants had a BMI range from 19 to 29. 

How much does Nettle cost?

Nettle will cost £449 in the UK at the time of launch. This price reflects the extensive clinical research and testing Nettle has undergone to be a medically approved and clinically validated health technology device. We will be offering payment plans to all customers and exclusive discounts for waitlist members.

I have PMDD, is Nettle for me?

Premenstrual dysphoric disorder (or PMDD) is a serious condition that - like much of women’s health - has been largely ignored by research, clinicians and solutions for too long. PMDD is a complex condition, with complex symptomatology, and women with PMDD do not necessarily have the same symptoms or experiences.

Nettle has been designed specifically with women in mind who have certain types of PMDD symptoms, especially low mood; and it may be worth exploring as an option alongside other treatment options. However, Nettle has not yet been tested on exclusively PMDD patient populations, and we’re currently investigating such benefits in a separate clinical trial.

If I sign up to the waitlist, am I committed to buy?

No, waitlist members will be given early access to Nettle when it launches and the opportunity to avail exclusive offers including a 10% discount. Once you join the waitlist, you will be notified when Nettle launches in your jurisdiction and how to purchase it.

How does Nettle work?

During your luteal phase, fluctuations occur in certain brain regions which contribute to symptoms of PMS and menstrual pain such as low mood, anxiety, brain fog and cramps.
Your brain runs on electricity, and neurons communicate using electrical signals called action potentials. Nettle uses the natural language of neurons to rearrange and regenerate neural pathways - a process known as neuroplasticity. This is done by administering safe and small electrical pulses to brain regions where these fluctuations occur. We are able to target them via the placement of the electrodes on the headband, one targeting your dorsolateral prefrontal cortex (DLPFC) and the other targeting your insula via your motor cortex (M1).

This stimulation gets neurons firing in a way that is more consistent with follicular phase activity, empowering you to feel your best even during the premenstrual phase. The technology Nettle employs is well-known and validated from the fields of depression and chronic pain treatment.

Have you conducted research with Nettle?

Yes, extensively.

We have run more than two years of tests on Nettle itself, and this builds on decades of research into the underlying neurotechnology and its mechanisms. These tests range across safety, efficacy, ergonomics, and more. The results of our WIND trial are available on our website and demonstrate significant improvement in low mood, pain and function after using Nettle for just 5 days, which is equivalent to one cycle.

We are in the process of setting up and conducting more trials, including one with the NHS that will test the efficacy of Nettle amongst patients with endometriosis and other trials for PMDD, among other conditions.

What symptoms is Nettle designed to manage?

Nettle is designed to help manage a variety of physical and psychological symptoms. Physical symptoms include menstrual pain and cramping, while psychological symptoms encompass low mood, irritability, anger management, mood instability, and brain fog. There is stronger evidence supporting Nettle's effectiveness for certain symptoms compared to others.

The technology behind Nettle has been rigorously tested in multiple clinical trials and continues to be assessed in ongoing studies to evaluate its effectiveness across various clinical endpoints.

Is Nettle safe?

Yes, Nettle has been rigorously tested for safety, and its underlying technology is supported by over 30 years of evidence demonstrating its safety for both short- and long-term use. However, as with all medical technologies, Nettle may not be suitable for everyone.

The key contraindications for using Nettle are diagnoses and history of epilepsy and/or seizures, and any pre-existing neurological implants, which could interfere with Nettle’s mechanism of action.

At launch, Nettle will be a regulated medical device, meaning that competent authorities in your jurisdiction will have assessed it as having appropriate clinical and safety evidence to be used as a medical device for the amelioration of PMS, PMDD, and menstrual pain symptoms. As part of this process, Nettle undergoes extensive safety testing, including ensuring that the device’s electrical and wireless emissions are well below the required safety limits. For example, the wireless emissions from Nettle are significantly lower than those emitted by your mobile phone. At launch, we’ll provide our exclusive waitlist members the opportunity to confirm that Nettle, as approved, is an appropriate medical treatment for them.

Nettle is currently going through medical certification. What does this mean?

In broad terms, this means we are currently demonstrating to the competent authorities that there is appropriate clinical and safety evidence for Nettle to be used as a medical device for the management of certain symptoms associated with PMS, PMDD and menstrual pain.

Until this process is completed, Nettle remains unavailable to purchase. We expect this process to be completed in June 2024 in the UK. At launch, we'll provide our exclusive waitlist members the opportunity to confirm that Nettle, as approved, is an appropriate medical treatment for them.


Learn more about the cycle brain connection.

Explore our blog where we break down neuroscience, menstrual health, and the cycle-brain connection.

March 20, 2024

The Menstrual Pain-Brain Connection

Pain is not just a symptom. It's a complex experience deeply influenced by biological, psychological, and social factors. Pain is also notoriously difficult to measure - and...
February 26, 2024

Neuroplasticity as a tool for optimising menstrual health

For centuries, the prevailing belief was that the adult brain was immutable to change. The concept of neuroplasticity—the brain's ability to change functionally or structurally...
November 16, 2023

Will Neuroimaging Revolutionise the Diagnosis of PMDD?

Despite its impact, it takes an average of 20 years for women to be accurately diagnosed with PMDD. The diagnosis is fraught with unique challenges, which include...
October 30, 2023

Periods, Productivity, and the Path to Progress

The statistics are glaring: menstrual symptoms undeniably influence productivity. However, while these numbers are revealing, capturing the full spectrum of menstrual symptoms...
October 17, 2023

The Problem with Painkillers: They Weren't Made for Women

Over 90% of women continue to grapple with menstrual cramps using an unevolved, 1980s-era solution: over-the-counter (OTC) painkillers. This makes even less sense when you look...
September 29, 2023

Women with severe PMS and PMDD experience depression-like symptoms every month

An increasing number of clinical studies are examining the brain in relation to the menstrual cycle, with a particular focus on women with severe PMS symptoms or Premenstrual...

Learn more about the cycle brain connection.

Explore our blog where we break down neuroscience, menstrual health, and the cycle-brain connection.


Blog title heading will go here

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

Blog title heading will go here

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

Women with severe PMS and PMDD experience depression-like symptoms every month

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

The Problem with Painkillers: They Weren't Made for Women

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

Periods, Productivity, and the Path to Progress

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

Will Neuroimaging Revolutionise the Diagnosis of PMDD?

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

Neuroplasticity as a tool for optimising menstrual health

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

The Menstrual Pain-Brain Connection

Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse varius enim in eros.
Full name
11 Jan 2022
5 min read

Join our family

You'll receive all the latest information on Nettle, it's underlying science and the cycle-brain connection.

By clicking Sign Up you're confirming that you agree with our Terms and Conditions.
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.