Quick Comparison
| Ashwagandha | Reishi | |
|---|---|---|
| Half-Life | 6-12 hours (withanolides) | Bioactive compounds accumulate with daily use |
| Typical Dosage | KSM-66 extract: 300-600 mg daily. Sensoril extract: 125-250 mg daily. Root powder: 3-6 g daily. Best taken with food. Can be taken morning or evening (does not cause drowsiness in most people). | Standard: 1000-3000 mg daily of extract. Dual-extract (water + alcohol extraction) preferred to capture both polysaccharides and triterpenes. Take in the evening due to calming effects. Spore oil: 500-1000 mg daily. Effects build over 2-4 weeks. |
| Administration | Oral (capsules, powder). Standardized extracts (KSM-66 or Sensoril) are preferred over raw root powder for consistent dosing. | Oral (capsules, powder, tincture, tea). Dual-extract preferred. Bitter taste in powder/tea form. |
| Research Papers | 9 papers | 8 papers |
| Categories |
Mechanism of Action
Ashwagandha
Ashwagandha's withanolide compounds (withaferin A, withanolide A, withanone) modulate the hypothalamic-pituitary-adrenal (HPA) axis, reducing corticotropin-releasing hormone (CRH) and adrenocorticotropic hormone (ACTH) signaling, thereby lowering cortisol production by 25-30% in stressed individuals. It acts as a GABA-A receptor positive allosteric modulator at the benzodiazepine site, producing anxiolytic effects without sedation. Ashwagandha inhibits acetylcholinesterase (AChE), raising acetylcholine levels in the hippocampus and cortex. The withanolides have anti-inflammatory properties via inhibition of NF-κB and COX-2, and antioxidant effects that reduce neuroinflammation and oxidative stress. It may support neurogenesis through upregulation of BDNF and its receptor TrkB, and modulation of the PI3K/Akt pathway.
Reishi
Reishi's triterpenes (ganoderic acids A, C, D, H; ganoderenic acids) modulate the HPA axis by reducing CRH and ACTH release, lowering cortisol via glucocorticoid receptor feedback. Ganoderic acids have direct sedative effects through GABA-A receptor modulation (possibly allosteric at the benzodiazepine site) and 5-HT2A/2C serotonergic modulation. Beta-(1,3)-(1,6)-glucan polysaccharides bind Dectin-1 and complement receptor 3 (CR3) on macrophages, natural killer cells, and dendritic cells, activating NF-kB and MAPK signaling for immune modulation. Reishi inhibits histamine release from mast cells via Fc epsilon RI downregulation and stabilizes mast cell membranes (anti-allergic effect). Antioxidant properties involve upregulation of superoxide dismutase (SOD1/SOD2), catalase, and glutathione peroxidase. Ganoderic acids may also inhibit 5-alpha-reductase and ACE.
Risks & Safety
Ashwagandha
Common
Gastrointestinal discomfort, drowsiness at higher doses, thyroid hormone elevation.
Serious
Can cause hyperthyroidism in susceptible individuals — avoid with thyroid conditions without medical oversight. Rare liver injury reports.
Rare
Vertigo, nasal congestion, sexual dysfunction.
Reishi
Common
Digestive discomfort, dry mouth, dizziness.
Serious
Rare hepatotoxicity reported — avoid with liver disease. May interact with blood thinners and immunosuppressants.
Rare
Allergic reaction, nosebleeds.
Full Profiles
Ashwagandha →
An Ayurvedic adaptogen used for over 3,000 years that has become one of the most popular and well-studied supplements for stress, anxiety, and cognitive function. Ashwagandha (Withania somnifera) significantly reduces cortisol levels, improves stress resilience, and enhances memory and reaction time. KSM-66 and Sensoril are the two most studied standardized extracts.
Reishi →
Known as the 'mushroom of immortality' in Chinese medicine, Reishi (Ganoderma lucidum) is an adaptogenic mushroom primarily used for stress reduction, immune support, and sleep improvement. Unlike the stimulating effects of Cordyceps or Lion's Mane, Reishi is calming and is best taken in the evening. Its triterpene compounds modulate the HPA axis and support GABAergic relaxation.