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20/08/2026

A recent randomised, double blind, placebo-controlled, parallel-group trial provides one of the stronger recent clinical evaluations of orally administered gotu kola (Centella asiatica) for skin ageing, although several limitations should be considered when interpreting its clinical significance. The study enrolled 112 Korean women aged 30 to 60 years with visible facial wrinkles and relatively dry skin. After exclusions, the per-protocol analysis included 53 participants receiving gotu kola and 52 receiving placebo. The intervention lasted 12 weeks and compliance exceeded 94%.

Participants received 200 mg daily of a spray-dried hydroethanolic extract of gotu kola leaves, taken as a single oral tablet 30 minutes after a meal. The extract was prepared using 70% ethanol and standardised to contain 7% asiaticoside (70 mg/g). Although the authors acknowledged the presence of other important triterpenes, including madecassoside, asiatic acid and madecassic acid, their concentrations were not reported. The publication did not provide the extraction yield or drug-to-extract ratio, so the equivalent amount of starting dried leaf material cannot be determined. However, typical hydroethanolic extraction results suggest that 200 mg of extract could correspond to approximately 0.8 to 1.3 g of starting leaf.

After 12 weeks, participants receiving the gotu kola experienced statistically significant improvements in several objective wrinkle parameters compared with placebo. Average wrinkle depth decreased by 11.1%, largest wrinkle depth by 14.4%, maximum wrinkle depth by 13.3%, total wrinkle volume by 13.7%, and surface roughness by 10.4%. Skin barrier function also improved, as demonstrated by a significant reduction in cheek transepidermal water loss, indicating enhanced barrier integrity. Cheek skin hydration increased significantly relative to placebo, although improvements at other body sites were smaller and inconsistent.

Statistically significant improvements were also observed in skin elasticity and skin brightness, but these changes were very small, approximately 0.7%, making their clinical relevance uncertain. The intervention was well tolerated, with no serious adverse events reported, and liver function, renal markers and haematological parameters remained within normal limits throughout the study.

The study has several notable strengths. It employed a rigorous randomised, double blind, placebo-controlled design, which was adequately powered for its primary endpoint, achieved high compliance with low dropout rates, and relied on objective instrumental assessments, rather than the subjective cosmetic evaluations that are mostly used in such trials.

However, important limitations temper confidence in the findings. The study was funded and conducted by the manufacturer of the commercial extract, introducing the possibility of sponsorship bias. The primary analysis was conducted on a per-protocol rather than an intention-to-treat basis, which may overestimate treatment effects. Apart from the wrinkle measurements, most statistically significant improvements were numerically small.

While no one should confuse an oral herbal extract with injectable cosmetic procedures, these findings do tempt one to describe gotu kola as "Botox in a bottle"—a tongue-in-cheek nickname from a colleague that is now reflected in its measurable ability to soften wrinkles naturally. The dose used in the trial was relatively low, implying that even better results might be obtained from prescribing normal doses of this herb.

For more information see: https://pubmed.ncbi.nlm.nih.gov/42196964/

15/08/2026

15/08/2026

15/08/2026

A randomised, double blind, parallel-group clinical trial compared a proprietary Dan Shen (Salvia miltiorrhiza) root extract (SAGX) with standardised liposterolic saw palmetto extract in men aged 40 to 80 years with mild-to-moderate lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH). Thirty participants were randomised (15 per group), with 25 completing the 12-week study (13 SAGX, 12 saw palmetto).

Participants received two soft gel capsules daily containing either SAGX (400 mg/day of an ethanol root extract standardised to contain at least 10% cryptotanshinone) or saw palmetto extract (320 mg/day of berry extract standardised to a fatty acid profile containing a minimum of 220 mg/g lauric acid).

Unfortunately, the paper does not report the drug:extract ratio of the Dan Shen extract. Consequently, the amount of starting crude root cannot be calculated from the published information, but it would probably be between 2 and 4 g/day.
Compared with saw palmetto, SAGX (Dan Shen) produced significantly greater improvements in lower urinary tract symptoms. Total International Prostate Symptom Score (IPSS) decreased by 4.6 points compared with 0.6 points for saw palmetto (p=0.031), while bladder storage symptoms improved by 2.7 points versus 0.2 points (p=0.003). SAGX also produced significantly greater improvements in reducing urinary frequency (p=0.006), lower urinary tract symptom-related quality of life (p=0.035) and improving erectile function, with the total International Index of Erectile Function (IIEF) score increasing by 8.2 points compared with 1.1 points for saw palmetto (p=0.005). Importantly, the 4.6-point reduction in IPSS exceeded the accepted minimum clinically important target of 3 points change, indicating that the benefits were clinically meaningful as well as statistically significant. Both treatments were generally well tolerated.

This was a small pilot study, with only 30 participants randomised and 25 completing the trial, making the results vulnerable to random error and potentially exaggerated treatment effects. The authors appropriately described the trial as hypothesis-generating rather than confirmatory, and the primary analysis used a per-protocol rather than a full intention-to-treat approach, increasing the risk of attrition (dropout) bias. The treatment period of only 12 weeks is also relatively short for a BPH/LUTS trial, where the gold standard is 6 months. A further limitation is the absence of a placebo control, which makes it difficult to determine the absolute efficacy of SAGX. However, the use of a standardised saw palmetto extract as the comparator is also potentially a strength, as high-quality liposterolic saw palmetto extracts have demonstrated clinically meaningful benefits for LUTS in several systematic reviews and meta-analyses. On the other hand, if the saw palmetto extract was of poor quality, the trial results would not suggest the superiority of Dan Shen, only that it is clinically effective.

Dan Shen, originally a key heart herb, is developing a surprisingly broad clinical repertoire, and this trial suggests a useful new application for this important medicinal plant.

For more information see: https://pubmed.ncbi.nlm.nih.gov/42280395/

15/08/2026

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07/08/2026

A new 12-week randomised, double blind, placebo-controlled trial has provided the strongest clinical evidence to date supporting saffron as a treatment for low mood and depressive symptoms (subclinical depression). Enrolling 202 adults aged 18 to 70 years, it is the largest clinical trial ever conducted on saffron for mood disorders and probably the most methodologically rigorous saffron study published to date.

The study used a proprietary saffron extract at a dose of 28 mg/day. Subclinical, subthreshold, or minor depression is defined as the presence of depressive symptoms but without fulfilling all the diagnostic criteria for major depressive disorder (MDD). Although participants in the trial did not have formally diagnosed MDD, their baseline DASS-21 (Depression, Anxiety and Stress Scale-21) scores averaged around 22, placing many in the severe symptom range despite being classified as ‘subclinical.’ At the same time, the cohort was relatively medically uncomplicated, with exclusions for major psychiatric diagnoses, significant medical illness, heavy alcohol use, smoking, ongoing psychotherapy and several medication classes, thereby creating a low-mood population largely free of potential confounders.

The primary outcome showed a statistically significant antidepressant effect favouring saffron. DASS-21 scores fell by 11.34 points in the saffron group compared with 8.42 points in the placebo group, producing a modest but clinically meaningful between-group effect size (Cohen’s d = 0.39, P = 0.010). Particularly noteworthy was the responder analysis: 72.3% of saffron-treated participants achieved a clinically meaningful reduction of at least 7 points on the DASS-21 depression scale compared with 54.3% in the placebo group (P = 0.010). However, the study also highlighted the enormous placebo responses that can be seen in low-mood trials. Much of the improvement occurred in both groups during the first 4 weeks, suggesting strong expectancy and nonspecific trial-participation effects.

Importantly though, the placebo response largely plateaued thereafter, whereas the saffron group continued gradual improvement across the full 12 weeks. This temporal divergence arguably strengthens the credibility of the findings because it suggests saffron may exert a progressively accumulating physiological effect rather than simply producing a short-lived expectancy response. Even longer treatment durations may have resulted in a larger separation between saffron and placebo.

Saffron did not significantly outperform placebo on most secondary measures including anxiety, stress and general wellbeing, although favourable trends were observed. The sleep findings were particularly interesting. Overall sleep outcomes were not statistically significant across the entire cohort, but exploratory subgroup analyses revealed meaningful improvements in participants with more substantial baseline sleep disturbance. In these participants, effect sizes for sleep improvement approached or slightly exceeded those seen for depression itself (d = 0.44). This suggests saffron’s sleep effects may be conditional and phenotype-dependent rather than universally sedative. The study also strengthened its methodological credibility by applying several observances: adjusting analyses for treatment expectancy effects, using intention-to-treat and per-protocol analyses, and incorporating daily mood ratings across the study duration.

The safety profile was excellent, with over 95% of participants rating tolerability as good or excellent and only a handful of mild treatment-related adverse events reported, including headache, abdominal pain and itchy skin. Overall, this landmark study substantially strengthens the evidence base supporting saffron as a genuine antidepressant phytomedicine, while simultaneously illustrating the profound challenge of the placebo response in mood research. But to my thinking, the very magnitude of the placebo response may actually enhance the credibility of the trial itself, because it reflects the real world.

In summary, this is arguably the most methodologically credible saffron mood trial yet conducted because of its size, duration, expectancy adjustment and rigorous analyses. The findings support saffron as a modest but clinically meaningful intervention for depressive symptoms, particularly in relatively healthy individuals, while also suggesting that its effects may accumulate progressively over time and potentially extend to sleep benefits in symptom-specific subgroups.

For more information see: https://pubmed.ncbi.nlm.nih.gov/40414301/