Common (>10%):

• Mild GI upset on empty stomach — take with food, particularly with KSM-66 600 mg dosing.
• Drowsiness/sedation, particularly with Sensoril or evening dosing of any extract; some users find this beneficial, others find it interferes with afternoon training.
• Initial 1-2 week "settling in" period with mild fatigue or grogginess; usually self-resolves.

Less common (1-10%):

• Headache (usually first week, dose-related, resolves with continued use or food co-administration).
• Vivid dreams or increased dream recall — mechanistic basis unclear; community-data consistent.
• Emotional blunting at >600 mg/day — dose-related, reversible on discontinuation. Users describe it as "less anxious AND less excited" — relevant for athletes whose competition mindset depends on accessible adrenergic activation.
• Mild libido shifts in either direction — community-data shows both ↑ (presumably via cortisol blunting + T-bump) and ↓ (presumably via sedation/SHBG shifts) reports.
• Loose stools or mild diarrhea (Sensoril more than KSM-66, dose-dependent).
• Mild rise in resting HR or BP — rare and small; opposite direction from what stress reduction would predict.

Rare-serious (<1%):

• Hepatotoxicity (DILI). Björnsson 2020 + Philips 2023 + multiple isolated case reports document ashwagandha-induced liver injury — predominantly cholestatic hepatitis pattern, onset 2-12 wk after starting, ages 21-75. LiverTox assigns likelihood category B (likely cause of clinically apparent injury). In Philips's series, 3 of 8 single-ingredient cases died — all had pre-existing chronic liver disease and developed acute-on-chronic failure. Background rate from global supplement use is very low (~30 published case reports against billions of doses consumed), but the asymmetric downside makes baseline ALT/AST + week-8 recheck mandatory. Stop immediately for jaundice, dark urine, RUQ pain, pale stools, pruritus, or fatigue-plus-anorexia constellation.
• Thyrotoxicosis trigger. Multiple case reports of hyperthyroid crisis when ashwagandha given to undiagnosed Graves or subclinical hyperthyroid patients. T3/T4 elevation is documented at 600 mg/day; in a euthyroid person this is biologically minor, in a Graves patient it can be the tipping push.
• Pregnancy abortifacient. Withanolides cross placenta and have documented embryotoxic effect in animal models; traditional Ayurveda historically used Withania for "labor induction." Hard contraindication in pregnancy and active conception attempts in women. Not Dylan-relevant but matters for partner-context if applicable.
• Autoimmune flare. Theoretical from withaferin A's NF-κB and Th1/Th2 modulation; case reports in Hashimoto's, lupus, RA contexts. Avoid in active autoimmune flares or in patients on biologics/immunosuppressants.
• Anesthesia interaction. Theoretical risk of prolonged GABAergic depression in surgical anesthesia; conservative practice is to discontinue 1-2 weeks before elective surgery.
• Sedation-impairment. Driving and operating heavy machinery — rare at standard doses but possible at high evening doses; assess individual response.

Specific watch periods: ALT/AST + TSH + free T3/T4 at baseline → week 4 (optional) → week 8 → end of cycle. Stop drug immediately for any jaundice, dark urine, RUQ pain, pruritus, or thyrotoxicosis symptoms (palpitations, heat intolerance, weight loss, anxiety surge). For Dylan: bake liver enzymes into the June 2026 bloodwork window — they may already be ordered.