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).

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.

Yes, extensively. We have run more than three 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.

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.

The physical and psychological symptoms that Nettle is designed to address all manifest as brain activity. Nettle has different modalities that target different brain regions. One, aimed at addressing physical symptoms via the Motor Cortex (M1), is designed to target the way the brain reacts to and processes pain signals. The other, aimed at addressing psychological symptoms via the Dorsolateral Prefrontal Cortex (DLPFC), is designed to modulate the way the brain’s cognitive centres work.

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.

Nettle is not designed to cure PMS, PMDD, dysmenorrhea, or any other women’s health condition. However, Nettle is a therapeutic that improves a range of physical and psychological symptoms that are commonly experienced by people diagnosed with such conditions. In our clinical trials, Nettle was proven to improve low mood, pain and functionality in our users, which are common symptoms of those struggling with menstrual health conditions.

No, Nettle does not have any direct impact on the hormone levels in your body and will not affect your menstrual cycle. The physical and psychological symptoms that Nettle is designed to address all manifest as brain activity in the dorsolateral prefrontal cortex and motor cortex.

Women’s health problems have been misunderstood and ignored for too long. We know how hard it is to receive appropriate diagnoses in this area, and we’re working to make Nettle available to everyone who needs it.

At launch, Nettle will be available for the reduction of pain, improvement of mood and functionality associated with menstruation and PMS, and will not require a formal clinical diagnosis. If you feel cognitive symptoms of PMS on the days leading up to your period, such as low mood, mood changes, irritability, anger, and cravings; and/or you feel menstrual pain that impacts your wellbeing during menstruation - Nettle may be for you. We also encourage you to share our doctor guide with your GP to evaluate if Nettle is the right solution for you.

If you feel cognitive symptoms of PMS that seem to be cyclical, such as low mood, mood changes, irritability, anger, and cravings - Nettle may be for you.

Sometimes, women on hormonal contraception or otherwise experiencing amenorrhea - missing periods - may still get cognitive symptoms associated with hormonal fluctuations, even though it may be more challenging to initially notice that these symptoms were triggered by hormonal fluctuations.

We intend for Nettle, once approved, to help manage those cyclical symptoms. The Samphire App will learn alongside you about your symptoms’ predictability, making management easier over time.

Nettle is controlled through the Samphire mobile application on your phone, using Bluetooth connection. The Samphire application will be available to download on the Apple and Google app stores. It will give you full control over Nettle and help you see your progress over time. The application integrates with cycle tracking, allowing you to create personalised schedules and routines, learn about symptoms over time, and improve predictability.

We have not run trials specifically including only women with a diagnosis of PCOS. However, Nettle has been designed specifically with women in mind who have certain types of PCOS symptoms; and it may be worth exploring as an option alongside other treatment options. However, Nettle has not yet been tested on exclusively PCOS patient populations.

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.

We, like you, are frustrated by the lack of research and effective solutions for chronic women’s health conditions. Endometriosis - experienced by 1 in 10 women - is high up on that list.

One of the landmark symptoms of endometriosis is serious menstrual pain - known as dysmenorrhea. Nettle is not intended to cure any conditions. However, while Nettle does not treat endometriosis, it is intended to help manage one of its most debilitating symptoms - that of menstrual pain, making the life of women with endometriosis easier. So far, women with endometriosis are common among our early testers, and say their lives are much better once they have an option for drug-free pain management, which also helps them with mood management during PMS.

You can see the price of Nettle in your country by going to the checkout page. This price reflects the extensive clinical research and testing Nettle has undergone to be a medically approved and clinically validated health technology device. We offer payment plans to all customers using third party payment providers.

Yes. However, Nettle needs to be applied for 20 minute-sessions daily during the late luteal phase, which makes it a high-intensity in-clinic treatment, so we recommend using Nettle in at-home settings for convenience and flexibility.

We have not run trials specifically including only women with a diagnosis of PMDD and/or PCOS. However, about 40% of women recruited for their PMS symptoms in our WIND clinical trial met the clinical diagnostic criteria for PMDD, as determined by post-hoc analyses. Our clinical trials did not collect data on existing PCOS diagnoses.

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. 

Though Nettle has been verified to offer promising benefits in managing mood symptoms associated with premenstrual syndrome (PMS), its efficacy for the treatment of major depressive disorder (MDD) specifically has not been tested. However, large-scale meta-reviews have determined that there is level A (definitely effective) evidence for the use of tDCS targeting the dorsolateral prefrontal cortex in the treatment of MDD, and more research continues to emerge. The use of Nettle for MDD treatment should be technically similar to the use of any other tDCS equipment targeting the DLPFC, but would be considered to be “off label” in the context of Nettle’s intended use.

Though Nettle has been verified to offer promising benefits in managing menstruation-related pain through its transcranial direct current stimulation (tDCS) technology, its efficacy for chronic pain that is not of menstrual origin has not been clinically validated. Large-scale meta-reviews have determined that there is level B (probably effective) evidence for the use of tDCS targeting the motor cortex in the treatment of neuropathic pain, migraines, fibromyalgia and stroke rehabilitation, and more research continues to emerge. However, chronic pain can arise from various causes and might require different interventions targeting the specific mechanisms involved in each type of pain. At the moment, recommending Nettle for chronic pain unrelated to menstrual conditions is not yet supported by the current scope of clinical evidence. 

Though Nettle has been verified to offer promising benefits in managing mood symptoms associated with premenstrual syndrome (PMS), its specific efficacy in treating premenstrual dysphoric disorder (PMDD) has not been clinically validated. It is worth noting, however, that PMDD is severely under-diagnosed. In Samphire’s clinical trials focused on PMS, post-hoc analyses showed that 38% of women in the sample matched the clinical diagnostic criteria for PMDD even though patients believed to be experiencing only PMS symptoms.

Since Nettle's clinical validation pertains specifically to managing mood symptoms associated with PMS, it may not be appropriate to recommend it as a primary treatment for PMDD. PMDD often requires a comprehensive approach, including psychotherapy, medication, and lifestyle changes. Given that Nettle is not known to have any interactions with other treatments, it may be a suitable option to incorporate into a holistic PMDD treatment plan. Before recommending Nettle or any other treatment to patients with PMDD, it's essential to consider their individual symptoms, medical history, and preferences. Consulting with a healthcare professional who specialises in PMDD management would be prudent to ensure the most appropriate and effective treatment plan for your patients.

From a technical and scientific standpoint, Nettle stimulates two regions of the brain - the DLPFC, associated with mood improvement, and the motor cortex, associated with pain relief, - while Flow Neuroscience’s device only stimulates the DLPFC, associated with mood improvement. 

From an intended use perspective, Flow Neuroscience’s device is approved for the treatment of Major Depressive Disorder (MDD) only. Nettle is approved to assist in the management of pain relating to menstruation and mood symptoms relating to premenstrual syndrome.

Therefore, if your patients are interested in managing mood and pain symptoms, associated with menstruation, Nettle is a better fit. If your patients are interested in managing MDD only, Flow Neuroscience’s device is a better fit.