Hericium erinaceus (Bull.) Pers. (Hericiaceae; Engl,: Lion’s Mane mushroom), is a toothed fungus endemic to the Northern Hemisphere. This unique looking fungus has garnered significant attention in recent years for its potential cognitive and mood-enhancing properties. Traditionally used in East Asian cuisine and medicine, this distinctive fungus has seen a surge in popularity as both a culinary ingredient and dietary supplement in Western countries.

While much research has focused on the effects of H. erinaceus in populations with cognitive impairment or mood disorders, there is growing interest in its potential benefits for healthy individuals. Preclinical studies have demonstrated that bioactive compounds in lion’s mane, such as hericenones and erinacines, can promote nerve growth factor (NGF) synthesis and potentially support neuroplasticity (1). These findings suggest that consuming Lion’s mane may have cognitive benefits even in the absence of pathology.

Addressing cognitive and mood impairments is increasingly important for public health. Neurological diseases contribute significantly to physical and cognitive decline, affecting 15% of the global population (2). The prevalence of mood disorders, such as anxiety and depression, is also rising. In 2019, anxiety disorders affected 4.05% of the global population, a 55% increase from 1990, with rates rising during the COVID-19 pandemic (3, 4).

Due to the increasing prevalence of neurodegenerative and mood disorders, it is more vital than ever to discover treatments that may help to alleviate these ailments. Hericium erinaceus has shown potential in treating a wide range of Central Nervous System (CNS) disorders. H. erinaceus contains a range of different compounds with a variety of biological activities (1) including erinacines and hericenones, which enhance growth factor (NGF) release (5).

Tsai-Teng et al. (6) demonstrated that erinacine A-enriched H. erinaceus supplementation significantly attenuated amyloid β plaque deposition in transgenic mice, indicating potential therapeutic effects for Alzheimer’s disease. Additionally, H. erinaceus extracts have shown antidepressant-like effects in mice, acting through mechanisms such as hippocampal neurogenesis (7) and induction of the brain-derived neurotrophic factor (BDNF) pathway, which is critical for neuronal survival and neurogenesis (8). Another murine study found that H. erinaceus increased levels of serotonin, dopamine, and noradrenaline, neurotransmitters that are often decreased in depression (9).

Human studies on H. erinaceus and depression are limited. One study by Vigna et al. (10) found that 8 weeks of H. erinaceus supplementation improved anxiety and depression measures in overweight or obese participants, also increasing circulating pro-BDNF levels. H. erinaceus has also shown potential in improving cognitive functions in individuals with mild cognitive impairment. Mori et al. (11) found cognitive improvement after 16 weeks of 250 mg daily H. erinaceus supplementation in older adults. Saitsu et al. (12) demonstrated cognitive improvements in participants consuming 2.4 g of H. erinaceus daily for 12 weeks. Docherty et al. (13) found an increase in performance on the Stroop task (a cognitive test measuring response inhibition) following a single 1.8 g dose of H. erinaceus in a young, healthy population indicating acute cognitive-benefits of H. erinaceus. This study also indicated an improvement in reported stress following 28-days chronic supplementation with H. erinaceus.

Our study extends recent research by Docherty et al. (13) by focusing solely on the immediate effects of a higher, more concentrated dose derived exclusively from the fruiting body of H. erinaceus. This approach addresses the fact that within the EU and UK, mycelial extracts or preparations of lion’s mane mycelia are not allowed to be consumed within food products or nutritional supplements however fruiting body extracts are permitted (14). The distinction between fruiting body and mycelial extracts is significant due to the differing profiles of bioactive compounds. Fruiting bodies are rich in hericenones, which have been shown to enhance cognitive function and mood (1). In contrast, mycelia contain higher concentrations of erinacines, known for their neurotrophic effects.

The effects of Hericium erinaceus on cognition (15, 16) and mood have received considerable attention, with research primarily focusing on its benefits for individuals with nervous system diseases. However, the potential cognitive and mood benefits of H. erinaceus in healthy individuals are also of significant interest. Our study investigates these acute effects in a young, healthy population, which is a less commonly studied demographic. By using an extract derived specifically from the fruiting body of H. erinaceus, our research aims to provide unique insights into its efficacy for cognitive enhancement in healthy adults.

A total of twenty adults were initially recruited, however two participants failed to attend the familiarisation/practise day, therefore eighteen participants of which 10 were male and 8 were female (see Table 3 for demographic information of the sample) were randomised and all completed the study (see Figure 2). Only main effects and interactions related to Intervention are reported as these are the most pertinent to establishing the acute effects of H. erinaceus on cognition.

There was no significant main effect of Intervention (active drink vs. control drink), or an Intervention x Time interaction for the composite measure of global cognitive function (all p > 0.05) and the composite measure of mood (all p > 0.05), see Table 4 for means and standard deviations. The higher the value, the better the cognitive performance or mood.

However, the MANOVA of the individual cognitive and mood measures revealed a main effect of Intervention (V = 0.81, F (10.8) = 3.30, p = 0.05, η_p² = 0.81) as well as an Intervention x Time interaction (V = 0.79, F (10.8) = 2.94, p = 0.07, η_p² = 0.79) that approached significance.

In relation to the trend for a main effect of Intervention, examination of the Univariate tests suggest this could be due to effects for the Pegboard – Dominant (F (1.17) = 10.41, p = 0.01, η_p² = 0.38) and Flanker (F (1.17) = 4.50, p = 0.049, η_p² = 0.21) tasks, with pairwise comparisons showing better performance in the active drink compared with the control drink condition for the Pegboard - Dominant task (mean difference = −0.40, SE = 0.12, p = 0.01; active drink M = 0.20, SE = 0.23; control drink M = −0.20, SE = 0.19) but a trend for worse performance in the active drink condition compared to control drink for the Flanker task (mean difference = 0.38, SE = 0.18, p = 0.05; active drink M = −0.19, SE = 0.13; control drink M = 0.19, SE = 0.21).

However, perhaps of most interest and relevance is the trend toward an Intervention x Time interaction, with Univariate tests revealing this could be due to effects for the Pegboard – Dominant (F (1.17) = 15.75, p < 0.001, η_p² = 0.48), Pegboard – Non-dominant (F (1.17) = 19.31, p < 0.001, η_p² = 0.53), and Flanker (F (1.17) = 4.87, p = 0.04, η_p² = 0.22) cognitive tasks and possibly the Trails B (F (1.17) = 4.42, p = 0.05, η_p² = 0.21) task and PANAS-positive mood measure (F (1.17) = 3.59, p = 0.08, η_p² = 0.17), although notably the effects for the latter two measures were only trends.

Pairwise comparisons showed significantly better performance in the active drink condition compared to control drink at the post-drink timepoint for the Pegboard – Dominant task (mean difference = −0.83, SE = 0.14, p < 0.001; active drink M = 0.49, SE =0.21; control drink M = −0.34, SE = 0.24) with no significant difference at baseline (p > 0.05). Furthermore, there was significant improvement in performance following the active drink compared to baseline (mean difference = −0.58, SE = 0.12, p < 0.001; Baseline M = −0.09, SE = 0.25; Post-drink M = 0.49, SE = 0.21), which was not observed for the control drink (Figure 3).

For the Pegboard – Non-dominant task, although performance was significantly better in the control drink compared with the active drink condition at baseline (mean difference = 0.72, SE = 0.28, p = 0.02; active drink M = −0.35, SE = 0.20; control drink M = 0.37, SE = 0.31), performance significantly increased following the active drink compared to baseline for this task (mean difference = −0.52, SE = 0.12, p < 0.001; Baseline M = −0.35, SE = 0.20; Post-drink M = 0.17, SE = 0.23), whereas there was a significant decline in performance following the control drink (mean difference = 0.55, SE = 0.23, p = 0.03; Baseline M = 0.37, SE = 0.31; Post-drink M = −0.18, SE = 0.16).

Furthermore, for the Trails A task, performance significantly decreased following the control drink compared to baseline (mean difference = 0.35, SE = 0.12, p = 0.01; Baseline M = 0.11, SE = 0.22; Post-drink M = −0.24, SE = 0.16).

Conversely, for the Flanker task, performance was significantly worse for the active drink condition compared with control drink (mean difference = 0.84, SE = 0.20, p < 0.001; active drink M = −0.37, SE = 0.16; control drink M = 0.47, SE = 0.09) at the post-drink timepoint (no significant difference at baseline, p > 0.05).

Also, for the Trails B task, a significant decline in performance was evident following the active drink compared to baseline (mean difference = 0.42, SE = 0.13, p = 0.01; Baseline M = 0.13, SE = 0.20; Post-drink M = −0.28, SE = 0.21).

There were no other significant main effects, interactions or pairwise comparisons.

Z score data (means and standard deviations), for each cognitive and mood measure are shown in Table 5. The higher the value, the better the cognitive performance or mood.

This is one of the few studies to investigate the acute effects of H. erinaceus extracts on cognition and mood in healthy younger adults. Whilst there was no overall effect on cognition as determined by the global composite measure, when cognitive tasks were analysed individually, acute consumption of H. erinaceus resulted in improved psychomotor skill. However, there was no evidence for a beneficial effect of the extract on mood in this study.

Interestingly, our investigation unveils the potential advantages of a single H. erinaceus dose on psychomotor skill/manual dexterity in a young and healthy cohort, as evidenced by improved performance on the pegboard test (dominant and non-dominant forms). The pegboard task is a widely used measure of psychomotor performance and manual dexterity. In this task, participants are required to insert pegs into holes on a board as quickly and accurately as possible. It assesses hand-eye coordination, fine motor skills, and the speed of information processing. The primary outcome measure for this task is the total number of pegs correctly placed within a specified time limit. Including the pegboard task in our study aimed to capture any potential acute effects of H. erinaceus on these specific cognitive and motor abilities.

The nuanced nature of acute cognitive effects seen with H. erinaceus extract in the current trial are in agreement with those of a recent trial in a similar population by Docherty et al. (13) who also observed an acute benefit to cognition only for a specific test measuring a particular cognitive ability. However, whilst in this acute trial we did not observe any beneficial effects on mood, Docherty et al. (13) reported a trend toward reduced subjective stress following chronic supplementation, suggesting that whilst specific cognitive effects can occur acutely in healthy younger adults, mood effects may only be evident following chronic supplementation.

Conversely, acute consumption of the H. erinaceus extract appeared to impair performance on the Flanker and Trail making B tests, both of which assess aspects of executive function (34, 35). Taken together, these conflicting results suggest that the effects of H. erinaceus extract on cognitive function in a young population 90 min after a single (3 g) dose are inconclusive based on this study. The lack of conclusive evidence on the beneficial cognitive effects of H. erinaceus extract is in alignment with the findings of a study conducted by Grozier et al. (36), who also measured cognitive changes in a young, healthy adult population after 4 weeks of H. erinaceus extract consumption and found no significant changes in cognition. However, considering this was a trial with a relatively small sample size, all cognitive results should be interpreted with caution and require replication in future studies to validate the findings. Furthermore, the mechanisms that underlie potential acute cognitive benefits of H. erinaceus are largely unknown and establishing these could be an aim of future research.

Previous studies demonstrating positive effects of H. erinaceus on depression and anxiety, such as those by Okamura et al. (37) and Vigna et al. (10), took place over 4 and 8 weeks, respectively. In the 2019 study by Vigna et al., participants were supplemented with a 500-milligram capsule, using an 80:20 mycelium to fruiting body ratio with each individual ingesting 84 grams of H. erinaceus over an eight-week period. These findings may be attributed to its role in impacting monoaminergic pathways, promoting neurogenesis and neurotrophic factors expression (including nerve growth factor), and/or exhibiting anti-inflammatory effects by modulating expression levels of IL-6, TNF-α, and NF-κB (38). Our acute study showed no statistically significant improvements in positive and negative mood as measured by the PANAS after H. erinaceus consumption when compared to the control. Our findings align with those of a study in a population of healthy adults where a single dose of H. erinaceus did not result in a reduction in stress. However, when supplemented for 28-days, a trend toward reduced subjective stress was observed (13). Most previous studies were conducted on populations that were depressed, whereas our study only included individuals without any clinician diagnosed mood disorders. It may be the case that H. erinaceus only confers positive mood changes in those experiencing mood disorders. Another possibility is that there is less measurable variance post-intervention in those with stable mood patterns such as the population we tested in this study.

A notable aspect of this study is that neither the H. erinaceus extract beverage nor the control contained additional active ingredients. Thus, any cognitive improvements are likely due to H. erinaceus metabolites. The study used a dosage of 3 grams of extract, equivalent to 30 grams of fresh lion’s mane fruiting body, which is higher than previous trials that typically used lower dosages. Furthermore, this study focused solely on the fruiting body, while culinary consumption of lion’s mane can be tenfold this amount. The 5% maltodextrin content, incidental from the spray drying process, is unlikely to significantly affect cognitive tests. It is possible the positive changes in mood and cognition that occurred in previous studies take longer than 90 min or are only evident following chronic supplementation. Due to the difficulty in observing measurable change in healthy individuals compared to those with cognitive decline, should benefits in such a population be evident, a longer period of supplementation may be necessary in order to observe them.

Future research might benefit from encapsulating the extract, as olfactory stimuli can influence mood and cognition (39). Positive changes in mood and cognition might take longer than 90 min to manifest or require chronic supplementation. Observing measurable changes in healthy individuals can be challenging; hence, a longer supplementation period may be necessary to detect benefits.

As this was an investigation with 18 participants, larger randomised controlled trials with a wide range of doses are warranted in order to demonstrate the potential beneficial effects of a single dose of H. erinaceus on mood and cognition. In addition, when designing acute trials, researchers could also consider increasing the delay between consumption of the test interventions and the post-intervention cognitive test session to more than 8 h. Previous studies have indicated that erinacine S, thought to be one of the bioactive compounds in H. erinaceus, can be detected in rats 2 h after administration, reaching peak concentration 8 h after oral administration in rats (40). However, this was not considered to be practical for the present human intervention study and due to the limited research of H. erinaceus in humans, the time it takes for erinacine S to reach peak concentration in human plasma is currently unknown, therefore post-intervention testing after a delay of 90 min was considered appropriate for this study. Furthermore, it is important to note that different organisms have different metabolism rates, therefore a study to determine bioavailability in humans would be warranted. It may also be prudent to test at more than one post-intervention timepoint to increase the likelihood of detecting any cognitive and mood effects and to determine changes over time.

Lion’s Mane mushroom (LMM) extracts may yield varying benefits due to differences in active ingredients. Not all LMM extracts contain equal proportions of purported bioactives. Variability arises from factors such as the source of raw material, extraction methods, and extract constituents. For example, extracts derived from the fruiting body of Hericium erinaceus, as regulated by the EU Novel Foods Catalogue (14), differ from those utilising both fruiting body and mycelium. These differences are underscored by research showing distinct bioactive profiles between the fruiting body and mycelium (1, 41). Moreover, the use of solvents such as ethanol, methanol, or water significantly impacts bioactive yield and consumer acceptance. While water extraction aligns with preferences for natural and safe products, ethanol extraction is more favoured in extraction of terpenoids including hericenones, as highlighted by Chang et al. (42).

Aqueous extractions have been used traditionally in foods, extensively, such as in soups and mushroom teas made from the fruiting body, remain traditional and widely accepted, whereas using organic solvents or supercritical CO2 extraction methods (43) —which may enhance yield and stability— require more consumer awareness. Historically tinctures using mushrooms as a traditional medical product were extracted by ethanol, but there is no evidence it has been used for food. Additionally, techniques like spray drying improve extract stability and ease of use (20), addressing consumer and regulatory expectations.

While this study utilised a H. erinaceus extract derived from the fruiting body, future research could delve deeper into analysing factors affecting efficacy. This highlights the importance of considering Hericium erinaceus extract variability in future studies. Future research should also consider including clinical and biochemical parameters, as well as quantifying bioactives within the administrative extract to help elucidate the potential mechanisms of action behind any beneficial effects of H. erinaceus on cognition and mood.

In conclusion, this study investigating the effect of H. erinaceus on cognition and mood in healthy younger adults was inconclusive. Whilst improved scores on certain cognitive measures suggest potential benefits to motor dexterity, this finding was contradicted by negative results in other tests. Furthermore, no beneficial effects on mood were detected, possibly due to the research being conducted on healthy participants, the dosage of H. erinaceus administered and the acute design of the study with only a single dose consumed. To date there are still a limited number of studies looking at the effects of H. erinaceus in humans. Future studies looking at the acute effects after a single dose of H. erinaceus should consider appropriate dosing for the population of interest, as well as the time between consumption and testing, or potentially testing at several time points following consumption. Further studies in healthy populations could clarify the mixed results of this study and expand our knowledge of the therapeutic potential of H. erinaceus for the wider population. It would also be interesting to investigate acute supplementation with H. erinaceus in compromised populations where there may be a greater opportunity to observe cognitive and mood benefits. Finally, understanding of the potential mechanisms of action related to effects of H. erinaceus on cognition and mood is currently limited and should be a focus of future research.