Quick Comparison

AshwagandhaReishi
Half-Life6-12 hours (withanolides)Bioactive compounds accumulate with daily use
Typical DosageKSM-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.
AdministrationOral (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 Papers9 papers8 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.

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