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A new care pathway for menstrual health

Discover Nettle, a non-invasive brain stimulation wearable powered by transcranial direct current stimulation (tDCS) clinically proven to reduce symptoms of PMS and menstrual pain. With zero severe side effects reported, Nettle could be a life-changing alternative for your patients.

Our partners are leaders in brain stimulation research

Nettle was developed based on groundbreaking studies led by our research collaborators, Professors Rodrigo Pegado and Maria Micussi, previously of the Federal University of Rio Grande do Norte and now affiliated with Harvard University. Their research demonstrated significant reduction of PMS and pain symptoms via non-invasive brain stimulation. Their expertise has been invaluable in guiding our subsequent trials and conducting clinical research with Nettle.

Our RCT triple blind trial was peer-reviewed in May 2024

We ran an independent clinical trial investigating the short-term (single period intervention) effects of using Nettle for alleviating both PMS and menstrual pain symptoms in women experiencing menstrual pain (primary dysmenorrhea) and premenstrual syndrome (measured with the PSST scale). Results outperformed traditional treatments and are likely to improve with sustained use over a minimum of 3 cycles.

Our NHS Pilot commences in June 2024

We have been given funding and approval to run and Endometriosis-focused study helping to alleviate chronic pelvic pain in endometriosis patients (double-blind, sham-controlled) in collaboration with the NHS commencing in June 2024. This will be our first clinical trial that investigates the effects of Nettle on endometriosis patients.

Empower your patients with choice

Treatments for women’s health conditions frequently entail side effects or inconsistent effectiveness, often due to inadequate testing or a lack of consideration for female physiology. Many women are actively seeking natural and non-invasive remedies for common issues like PMS and menstrual pain. Healthcare providers play a crucial role in educating and offering these solutions to your patients, enabling them to access and confidently utilise them.


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.

How does Nettle work?

During the 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 menstrual cramps.


Nettle uses a type of non-invasive brain stimulation called transcranial direct current stimulation (tDCS) to adminster safe and small electrical pulses to the brain regions where these fluctuations occur. It is able to target these regions via the placement of the electrodes on the headband, one targeting the dorsolateral preftontal cortext (DLPFC) and the other targeting the insula via your motor cortex (M1).

Increases neuronal excitability

Regenerates neural pathways

Rebalances activity in the brain

Three landmark studies that built Nettle

Nettle is founded on over 30 years of clinical research into its underlying technology transcranial direct current stimulation (tDCS) in the areas of chronic pain and depression treatment. In 2020, our research collaborators applied this technology to address menstrual symptoms related to pain and mood. Since then, we have conducted our own clinical trials, which examine the impact of targeted tDCS on both pain and mood symptoms.

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

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

The purpose of this trial was to examine the impact of transcranial direct current stimulation (tDCS) targeting the dorsolateral prefrontal cortex (DLPFC) on anxiety and functionality in patients with primary dysmenorrhea. The study demonstrated significant improvement in mood for 84% of users, concluding that tDCS appears to be an effective therapeutic approach for improving anxiety and functionality in women with primary dysmenorrhea.

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

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

The purpose of this trial was to explore the impact of transcranial direct current stimulation (tDCS) targeting the motor cortex (M1) on pain, mood, and physical performance in patients with primary dysmenorrhea (PDM). Over the course of one week, non-invasive brain stimulation (tDCS) reduced pain symptoms in 89% of participants, offering preliminary evidence of tDCS's potential in managing menstrual pain.

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

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

Our study with Nettle measured the impact of brain stimulation on both pain and mood symptoms by targeting both the M1 and DLPFC during the five sessions our users underwent. In just one month’s use Nettle, results showed a 53% reduction in pain, a 34% improvement in mood, and an 11% improvement in function. This lays the groundwork for further research into Nettle, particularly  over a three-month period, during which we anticipate further  improvements in symptoms due to neuroplasticity effects.

Our science validates that Nettle is a safe and highly effective alternative, offering numerous advantages over traditional treatments.

Below are the results from our clinical trial, a Triple-Blind, Randomised Sham-Controlled Trial, that focused on three metrics: pain, mood, and function or the ability to perform everyday tasks. In just one month’s of use each symptom improved by:

53%

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.

34%

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.

11%

Function

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.

Zero severe side effects reported.

While Nettle may take time to reach it’s full effect (most users will feel its full effect after 3 months of consistent use), this natural approach is proven to not only yield longer-term results but also come with zero severe side effects.

Nettle Data

In real-life data with our early users the most commonly reported side effect was mild tingling during sessions which subsided shortly after.

Historical Data

A 2020 study that is a review of over 2,000 tDCS sessions found side effects to be mild, transient and well-tolerated.

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)

Get our guide

Request a copy of our detailed guide for healthcare practitioners and get in touch with us to learn more about our partnership program.

FAQs

Can Nettle be used as an in-clinic treatment?

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.

Have you tested Nettle on women with PMDD/PCOS?

We have not run trials specifically including only women with a diagnosis of PMDD and/or PCOS. However, 38% 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.

Can I recommend Nettle for depression that is not of menstrual origin?

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.

Can I recommend Nettle for chronic pain that is not of menstrual origin to patients?

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. 

Can I recommend Nettle to my patients with PMDD?

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 and that 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 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.

How is Nettle different from Flow Neuroscience?

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.

Still have questions?

Get in touch with us to learn more about Nettle and our partnership programme.

Join our waitlist to get early access to Nettle

Nettle launches summer 2024. Waitlist members will receive early access to our releases and exclusive offers. Keep an eye on our newsletter for the latest updates on our clinical trials and neuroscience content.

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