Ashwagandha

• Stress and anxiety: Research suggests ashwagandha may reduce perceived stress and anxiety and lower cortisol (moderate evidence; multiple RCTs and meta-analyses).
• Sleep quality and insomnia: May improve sleep quality, sleep onset latency, and overall well‑being in people with insomnia or high stress (moderate evidence; meta-analyses of small RCTs; effects are generally modest).
• Physical performance: May increase strength, power, and muscle mass when combined with resistance training, and modestly improve VO2max/endurance (emerging-to-moderate evidence; several small RCTs).
• Male reproductive health: May improve semen quality in men with infertility and slightly raise testosterone in stressed or infertile men (emerging evidence; small RCTs/observational studies; results mixed in healthy men).
• Thyroid function: In subclinical hypothyroidism, small trials indicate increases in T3/T4 and reductions in TSH; case reports describe precipitated hyperthyroidism (emerging evidence; use with caution and medical monitoring).
• Metabolic markers: Some studies report small reductions in fasting glucose, lipids, and CRP (emerging evidence; effects are modest and data heterogeneous).
• Cognitive function: Small trials in mild cognitive impairment and stressed adults report improvements in memory and processing speed (emerging evidence; more robust trials needed).

Common (usually mild, often dose-related):

• Gastrointestinal upset (nausea, diarrhea, abdominal discomfort), decreased appetite (1–10%).
• Drowsiness/sedation, fatigue, headache (1–10%).
• Dizziness, vivid dreams, dry mouth (uncommon).

Allergic reactions:

• Rash, pruritus; rare angioedema in sensitized individuals (rare; nightshade family cross-reactivity possible).

Cardio-metabolic:

• Mild decreases in blood pressure or blood glucose (usually mild; may be clinically relevant if on related medications).

Endocrine/thyroid:

• Increased thyroid hormones in susceptible individuals; rare cases of thyrotoxicosis (rare but potentially serious).

Liver:

• Rare cases of clinically apparent liver injury (often cholestatic or mixed DILI) reported; typically occurs within weeks; usually resolves after discontinuation but can be severe (rare but serious).

Neuro/CNS:

• Additive sedation with other CNS depressants (dose-dependent).

Commonly used ranges in studies (not prescriptive; optimal dose varies by individual and indication):

• Standardized root extract (e.g., ~5% total withanolides, such as some root-only extracts): 240–600 mg/day, often split as 300 mg twice daily for 6–12 weeks in stress/anxiety trials.
• Higher-withanolide root+leaf extracts (e.g., ~10% withanolides in some products): 125–250 mg/day for 8–12 weeks in stress/sleep studies.
• Sleep/insomnia trials: 120–600 mg/day for 6–12 weeks.
• Strength/lean mass trials: ~600 mg/day (often 300 mg twice daily) for 8–12 weeks alongside resistance training.
• Traditional Ayurvedic powders (churna): 3–6 g/day of root powder, typically with milk or ghee; modern trials more often use standardized extracts.
• Note: Product standardization (withanolide content), extract type (root-only vs root+leaf), and individual response vary. Start low, and use medical supervision if you have medical conditions or take medications.

• Pregnancy: Traditionally contraindicated; animal data suggest potential abortifacient effects at high doses; avoid unless specifically prescribed and monitored.
• Breastfeeding: Insufficient safety data; avoid.
• Hyperthyroidism or uncontrolled thyroid disease: May raise T3/T4; avoid or use only with clinician monitoring. Caution when taking levothyroxine.
• Autoimmune disorders (e.g., MS, SLE, RA, autoimmune thyroiditis): Immunomodulatory activity may exacerbate disease; avoid or use only under specialist guidance.
• Liver disease or history of drug-induced liver injury: Rare hepatotoxicity reported; avoid or use with baseline and periodic LFT monitoring.
• Diabetes or hypoglycemia: May lower blood glucose; monitor closely if using antidiabetic drugs/insulin.
• Hypotension or on antihypertensives: May lower BP; monitor.
• Hormone-sensitive conditions (e.g., androgen-sensitive prostate cancer): Possible small increases in testosterone; use caution and seek medical advice.
• Known allergy to plants in the Solanaceae (nightshade) family.
• Surgery: Discontinue at least 2 weeks before elective procedures due to potential sedative, blood pressure, glycemic, and thyroid effects.