The Green Herbalist Clinic

16/06/2026

Can a simple tea-derived combination ease period pain? A new placebo-controlled pilot study suggests that chamomile extract paired with L-theanine may dramatically reduce menstrual pain and several associated symptoms, producing improvement.

Prior clinical research suggests chamomile may reduce menstrual pain and associated symptoms in primary dysmenorrhoea, while L-theanine has separately shown potential benefits for mood regulation, relaxation and aspects of sleep quality. However, the advantages of a combination of these two agents have not been studied until now.

This randomised, double blind, placebo-controlled pilot study evaluated a ready-to-drink beverage containing chamomile extract plus L-theanine for primary dysmenorrhoea in 30 young women (15 active, 15 placebo). The active beverage delivered 480 mg chamomile extract and 200 mg L-theanine per 240 mL serving, with participants consuming two servings daily for five consecutive days spanning the menstrual period (two days before menstruation onset and then the next three days). The placebo was not inert, but rather a chamomile-flavoured beverage matched for appearance, volume and sugar content, designed to mimic the sensory characteristics of the extract without containing chamomile extract or L-theanine.

The magnitude of analgesic benefit reported was substantial. Mean visual analogue scale (VAS) pain scores fell from 6.07 to 2.60 in the active group, representing a 57.2% reduction, while numerical rating scale (NRS) pain scores fell from 6.13 to 2.73, a 55.5% reduction. In contrast, placebo produced only a modest VAS reduction from 5.47 to 4.60 (approximately 16%) with no statistically significant change in NRS scores. The intervention also reduced multiple associated symptoms, including lower abdominal pain (−52.9%), back pain (−56.3%), loss of appetite (−47.2%), stomachache (−43.1%), body pain (−42.5%), irritability (−45.1%) and depressive symptoms (−49.5%). Interestingly, the placebo beverage also improved some psychological variables suggesting either expectancy effects or a possible psychophysiological influence of the chamomile aroma/flavour itself. The authors themselves acknowledged that olfactory and flavour effects from the placebo may have confounded mood outcomes.

Surprisingly, given the reputation of L-theanine, sleep findings were more modest and nuanced than the pain outcomes. Total Pittsburgh Sleep Quality Index (PSQI) scores did not significantly improve, nor did sleep duration, sleep efficiency, sleep disturbances or subjective sleep quality. The only sleep parameter significantly improved was daytime dysfunction, which decreased by approximately 32%.

Mechanistically, this could plausibly relate more to reductions in menstrual pain and mood disturbance than to direct hypnotic effects. The L-theanine dose used here (400 mg/day total) was substantial and similar to doses used in some stress and sleep studies, while the chamomile dose was considerably higher than in many trials, although the extract concentration was unfortunately not reported. No phytochemical analysis was provided.

Overall, this was a promising study. However, it was underpowered, relied almost entirely on subjective outcomes, lasted for only a single menstrual cycle, and did not include a chamomile-only arm to determine whether L-theanine added anything meaningful. The placebo was also arguably active from a sensory perspective. Nonetheless, the size of the analgesic effect relative to placebo was notable and aligns with previous evidence that chamomile may exert clinically meaningful anti-prostaglandin and antispasmodic effects in primary dysmenorrhoea.

For more information see: https://pubmed.ncbi.nlm.nih.gov/41525193/

10/06/2026

Tossing and turning because your legs just won’t settle? Restless Legs Syndrome (RLS) affects millions of people and can have a major impact on sleep and quality of life. Emerging research suggests that supporting healthy circulation may help ease symptoms. Could improving microvascular blood flow be part of the solution?

Restless Legs Syndrome (RLS), also known as Willis-Ekbom Disease, is a condition associated with abnormal sensations in the legs that mainly impacts sleep. It is estimated that 5% of the general population and as many as 10% of those over the age of 65 have this disorder. One school of thought is that an impairment of venous and microvascular blood flow contributes to the problem, suggesting a role for herbs that can improve this pathophysiology, such as pine bark and grape seed extracts. In a recent clinical trial, 21 people took a proprietary French maritime pine bark standardised extract (PB) at 150 mg/day and 24 received standard management (SM) for 4 weeks.

There was a statistically non-significant improvement in the SM group. In contrast, improvement with PB supplementation was significant (p < 0.05) for all assessed parameters and had important clinical relevance, since 19 out of 21 people in the PB group reported a clear benefit from supplementation. The veno-arteriolar response was improved with PB, indicating a better axon-axon reflex response and a lower level of subclinical neural alteration. The need for pain management was significantly reduced (p < 0.05) with supplementation after 4 weeks, as only 4/21 PB subjects versus 16/24 in the SM-only group had to use analgesics. Minimal oedema, measured with the oedema tester, was significantly decreased by PB.

In terms of the characteristic symptoms of RLS, improvements in the PB group (compared to SM) included:

• 33 percent decrease in crawling (versus 3 percent decrease in control group)
• 30 percent decrease in creeping (vs. 7 percent decrease in control group)
• 41 percent decrease in pulling (vs. 7 percent decrease in control group)
• 63 percent decrease in throbbing (vs. 6 percent decrease in control group)
• 72 percent decrease in aching (vs. 3 percent decrease in control group)
• 48 percent decrease in itching (vs. 10 percent decrease in control group)
• 52 percent decrease in electric shocks (vs. 17 percent decrease in control group)
• 61 percent decrease in sleep problems (vs. 16 percent decrease in control group)
For more information see https://pubmed.ncbi.nlm.nih.gov/35815767/

06/06/2026

Contact dermatitis is a common skin condition that can impair the skin barrier, causing dryness, irritation, and discomfort. Emerging research suggests that Calendula officinalis may help support skin recovery.

Contact dermatitis, either allergic or irritant, is a common skin disease associated with disruption in the skin barrier, which affects patients’ quality of life and impacts their work capacity. A recent clinical trial evaluated whether adding a special Calendula extract to a standard emollient cream could improve recovery of the skin barrier after experimentally induced irritant dermatitis. Calendula was studied because of its longstanding traditional dermatological use and growing experimental evidence suggesting that its topical use may support skin barrier repair via wound-healing and anti-inflammatory mechanisms.

The study included 20 healthy volunteers aged 22 to 35 years, of whom 17 were women and 3 were men. On each participant’s forearm, three separate test sites were created: one received no treatment (control), one received the emollient base alone (placebo), and one received the same emollient cream containing Calendula extract.

The active cream contained 1% of a supercritical CO₂ extract of Calendula officinalis, applied at approximately 5 mg/cm² twice daily for 8 days following experimentally induced irritant dermatitis. The base cream contained petrolatum, paraffin, cetearyl alcohol and propylene glycol, all recognised barrier-supportive ingredients.

After sodium lauryl sulfate-induced irritation (a synthetic detergent), all skin sites showed reduced hydration and increased trans-epidermal water loss (TEWL), confirming disruption of the skin barrier. However, the Calendula-treated sites recovered more rapidly than both the untreated control and placebo-cream sites. By day 4, skin hydration at the Calendula site was significantly higher (35.1 AU) than both the placebo site (27.5 AU; p = 0.035) and untreated control site (24.5 AU; p = 0.017), with the superiority over control persisting to day 8 (30.5 vs 25.6 AU; p = 0.043). TEWL, a marker of skin barrier dysfunction, was also significantly lower at the Calendula site on day 3 compared with the untreated control site (30.7 vs 36.7 g/m²/h; p = 0.022), suggesting faster barrier repair. However, there was no significant improvement in erythema/redness, indicating that the primary effect appeared to involve barrier recovery and hydration support rather than any strong anti-inflammatory activity.

The Calendula extract, produced using supercritical CO₂ extraction at 30 MPa and 40 °C, preferentially concentrated volatile lipophilic (fat-loving) constituents rather than polar flavonoids. The result was a resinous, sticky and highly lipophilic extract. Analysis showed a terpene-rich phytochemical profile dominated by sesquiterpenes including γ-cadinene (13.8%), δ-cadinene (13.6%), α-muurolene (7.1%), α-cadinol (6.6%) and t-muurolol (5.5%). This type of Calendula preparation is therefore quite different from a traditional low-alcohol tincture or aqueous extract and is chemically much closer to a very high-strength ethanolic (say 90% ethanol) galenical preparation.

Overall, the study provides preliminary clinical support for the use of a lipophilic Calendula extract in cream form in contact dermatitis. The findings suggest it may function as a barrier-supportive topical that enhances skin hydration and accelerates recovery of impaired skin function. It also aligns with my clinical experience using a high-strength 90% ethanolic Calendula liquid in dermatological practice, especially diluted 1:20 with water for healing of stubborn wounds.

For more information see: https://pubmed.ncbi.nlm.nih.gov/41527980/

23/05/2026

First cold water swim of the year!!
Cold Water Swimming: More Than a Wake-Up Call

Cold water swimming may help improve mood, reduce stress, increase alertness, and support circulation. Regular exposure has also been linked to better stress resilience, reduced inflammation markers, and a stronger sense of well-being. Start gradually and use caution, as sudden exposure to cold can place stress on the heart and nervous system. Always swim with experienced people, take lessons, and swim at locations which provide lifeguards.

20/05/2026

Leg ulcers. Gotu Kola has a long history of use in traditional medicine for supporting wound healing, connective tissue repair, and venous health. Modern research suggests its active compounds, particularly asiaticoside and madecassoside, help strengthen capillaries, support collagen production, and improve microcirculation.

Recent research from Italy further highlights its potential in leg ulcer healing. In a three-month study of 160 patients with chronic venous insufficiency and leg ulcers, those receiving Gotu kola extract (675 mg daily) alongside standard care experienced faster and greater healing than standard care alone. After one month, 65% of ulcers had healed completely compared with 18.8% in controls, and by the end of the study, healing exceeded 96%.

These findings reinforce Gotu kola’s role as an important herb where circulation is compromised and tissue repair is delayed.

Gotu cola (Centella asiatica) leaf has a long and distinguished history in traditional medicine systems across India, Sri Lanka and Southeast Asia, where it has been valued as a restorative herb for both the mind and body. In Ayurvedic and traditional Chinese medicine it is closely associated with h

19/05/2026

Leg ulcers. Gotu Kola has a long history of use in traditional medicine for supporting wound healing, connective tissue repair, and venous health. Modern research suggests its active compounds, particularly asiaticoside and madecassoside, help strengthen capillaries, support collagen production, and improve microcirculation.

The research findings reinforce Gotu kola’s role as an important herb for use when circulation is compromised and tissue repair is delayed.
To find out more or to book an appointment.
https://www.thegreenherbalistclinic.com/

Gotu cola (Centella asiatica) leaf has a long and distinguished history in traditional medicine systems across India, Sri Lanka and Southeast Asia, where it has been valued as a restorative herb for both the mind and body. In Ayurvedic and traditional Chinese medicine it is closely associated with h

18/05/2026

Macular degeneration. Another recent finding is making my fascination with gotu kola even harder to ignore. After emerging evidence suggesting it may help reshape vascular plaque biology toward a more stable, lower-risk state, new research now points to something equally intriguing: this humble herb may also enhance macular resilience and potentially open an entirely new pathway in protecting ageing eyes.
To find out more or to book an appointment.
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For several years now I have been emphasising the importance of improving microvascular health in patients with, or at risk of, age-related macular degeneration (AMD), using Centella asiatica (gotu kola) as a central component of this strategy.

Now a recent randomised, double blind, placebo-controlled trial from Korea has evaluated a standardised extract of gotu kola (300 mg/day, standardised to asiaticoside at 14.1 mg/g) over 6 months in 80 adults aged 45 to 65 years with low baseline macular pigment optical density (MPOD). The study was methodologically sound, with good blinding, balanced baseline characteristics, low attrition, and both per-protocol and intention-to-treat (ITT) analyses reported.

The primary finding was a significant and progressive increase in MPOD compared to placebo. By Day 180, changes from baseline showed large between-group effect sizes: right eye (+0.06 vs 0.00; d = 1.26), left eye (+0.02 vs −0.02; d = 1.00), and average MPOD (+0.04 vs −0.01; d = 1.96), all highly statistically significant. The letter d above refers to Cohen’s d, a standardised measure of effect size. A value of 1.00 or higher, as seen in this study, represents an extraordinarily large clinical effect.

Benefits were already evident by Day 120. A responder analysis (defined rather permissively as any increase in MPOD) showed 94.7% responders in the treatment group versus 32.4% in placebo. Safety was reassuring, with no serious adverse events and no clinically meaningful changes in laboratory or vital parameters.
MPOD is a clinically useful surrogate marker of macular resilience, reflecting the concentration of lutein, zeaxanthin, and meso-zeaxanthin in the central retina. Higher MPOD is consistently associated with better visual performance (particularly contrast sensitivity, glare recovery) and a lower risk or slower progression of AMD. However, it is a surrogate marker rather than a direct measure of vision.

In a field where meaningful interventions are scarce, these findings signal a compelling new advance, showing that a non-carotenoid containing herb can measurably enhance macular resilience and potentially open an entirely new therapeutic pathway for AMD prevention and treatment.

For more information see: https://pubmed.ncbi.nlm.nih.gov/41901080/

18/05/2026

Atherosclerosis
Ever wondered whether a humble garden w**d could influence one of the most important drivers of cardiovascular disease? Gotu kola has long been valued for its effects on circulation and tissue repair, but emerging research suggests its potential may reach much further. New findings indicate this understated herb may not simply affect arterial plaque size — it may actually help transform plaque biology itself.
To find out more or to book an appointment.
https://www.thegreenherbalistclinic.com/

In case you haven’t already guessed, one of my favourite herbs is gotu kola (Centella asiatica). This unassuming w**d is a quiet testament to the profound power sometimes concealed within humble origins. Gotu kola bridges traditional wisdom and modern validation, demonstrating clinically proven capacities to restore microcirculatory integrity, enhance collagen architecture and regeneration, and refine connective tissue function. My next two posts reveal how this herb’s therapeutic potential has just been taken to an entirely new level, underpinned by some truly remarkable clinical findings.

Atherosclerotic plaques are fatty build-ups in our artery walls. But more than that, they can be thought of as chronic wounds in the arterial lining, driving the entire cascade of arterial disease, from impaired flow through to heart attacks and strokes. They differ not just in size, but in structure and composition and this strongly influences their risk profile. Using high-resolution ultrasound (including grey-scale imaging), clinicians can assess plaque volume, shape, density and uniformity. On this imaging, denser, more fibrous plaques appear brighter or “white” (echogenic) and tend to be more stable. Softer, lipid-rich plaques appear darker or “black” (echolucent) and are more prone to rupture, thrombosis and embolisation, leading to hard cardiovascular events. This difference is reflected in the underlying biology. Unstable plaque is typically richer in lipids, inflammatory cells, and fragile microvessels, while more stable plaque contains more collagen and organised structure. Rather than viewing plaques as simple obstructions to blood flow, this new understanding treats them as dynamic biological lesions, where vulnerability depends on multiple interacting factors.

A small presurgical study in 40 patients with advanced carotid plaques scheduled for carotid endarterectomy (a surgical procedure to remove atherosclerotic plaque from the carotid artery) compared six months of pine bark extract (150 mg/day) plus gotu kola extract (450 mg/day) against standard care. When the plaques were removed and examined, the differences were striking and consistent across multiple risk features. For example, calcification was present in 32% of treated plaques vs 100% of controls (7/22 vs 18/18), lipid-rich atheroma in 36% vs 89% (8/22 vs 16/18), and inflammatory cell infiltration in 35% vs 100% (7/20 vs 18/18). Markers of vascular instability were also reduced: VCAM-1 (36% vs 72%), ICAM-1 (32% vs 89%), intraplaque thrombosis (23% vs 67%), and haemorrhage (45% vs 78%). Even features linked to plaque fragility, such as neovessel formation and inflammation around thin-walled vessels, were roughly halved in the treatment group. Alongside this, plaque growth over the 6 months was +1.5% vs +4.8% in controls, indicating a meaningful slowing of progression.

Taken together, the gotu kola and pine bark therapy delivered a broad, system-wide shift in plaque phenotype. Specifically, the herbal intervention appears to move plaques away from a “vulnerable” state (lipid-rich, inflamed, angiogenic, thrombosis-prone) toward more stable, organised, and less reactive structures. Moreover, this clinical effect spans multiple biological domains simultaneously: inflammation, endothelial activation, microvascular instability, thrombosis and structural composition. In other words, rather than just shrinking plaques, the herbal combination seems to beneficially change what the plaque is made of and how it behaves.

This discovery has the potential to reframe the discussion around cardiovascular risk. Much of conventional thinking still emphasises plaque burden and lipid levels, but this study highlights that impacting plaque quality—its biology and stability—may be just as important. From a clinical perspective, it raises the possibility that interventions (especially phytotherapy) that act across multiple pathways could meaningfully reduce cardiovascular risk, not by dramatically reducing plaque size and development, but by making plaque less likely to rupture, thrombose and cause events. While the study is small and not outcome-driven, the magnitude and consistency of these morphological changes are intriguing, and they support a more rational true risk-based approach to cardiovascular intervention.

For more information see: https://pubmed.ncbi.nlm.nih.gov/36789998/

30/04/2026

Worth a read! Look after your gut health.

04/04/2026

Happy