Studies suggest Lion's Mane has an effect on both the production and receptor mediated cellular uptake of Serotonin, known as the "feel-good" neurotransmitter. Based on clinical studies, Lion's Mane can enhance serotonin production by promoting the activity of specific enzymes involved in its synthesis. It may also modulate serotonin receptors by increasing their sensitivity. Modulation allows for a more efficient transmission of serotonin signals, leading to improved mood stability and reduced symptoms of anxiety and depression.

Another study explored the effects of Lion's Mane on cognitive impairment induced by chronic mild stress—a common model for studying depression-related cognitive dysfunction. The results showed that administration of Lion's Mane improved memory and learning abilities while reducing anxiety-like behaviors. 

Niacin can indirectly reduce depression by increasing your body’s availability of serotonin. Niacin may cause skin flushing, which is a redness of skin due to vasodilation. It is harmless and subsides quickly.