Common (>10% users):

• At typical doses (500-1500 mg/day Meriva-equivalent): minimal. Bright yellow stools (the curcumin pigment) — harmless and dose-dependent.
• Mild bloating or soft stools, especially when starting. Taking with food eliminates this in most users.

Less common (1-10%):

• Mild nausea (especially with high-dose unformulated powders on empty stomach).
• Headache (rare, usually at >2 g/day Meriva-equivalent).
• Skin rash (very rare; usually idiosyncratic).
• Increased bowel frequency.

Rare-serious (<1% but worth knowing):

• Drug-induced liver injury (DILI) — the only meaningful safety signal in the literature. 2023 NEJM letter (Halegoua-De Marzio) documented 10 cases of probable curcumin-associated DILI (cholestatic-hepatocellular pattern), most in middle-aged women, mostly on high-bioavailability formulations (Meriva, Longvida) at doses 1000-3000 mg/day for 1-12 weeks. ALT typically 5-30× ULN, full recovery on discontinuation. Mechanism unclear — possibly related to bioavailability-enhanced systemic exposure pushing curcumin or its metabolites into hepatotoxic range in genetically susceptible individuals (HLA-B*35:01 association suggested for some flavonoid hepatotoxicities). Practical implication: get baseline ALT/AST on the June panel; recheck at 6 months. Discontinue immediately if jaundice, dark urine, RUQ pain, or fatigue + GI symptoms emerge.
• Iron deficiency at chronic high doses — curcumin's mild iron chelation can drop ferritin in iron-marginal individuals. Less concern in young men with red-meat-containing diets; potentially relevant if the user's June ferritin comes back low. Athletes can dip ferritin from training alone; chronic curcumin >1000 mg/day could compound this. Watch ferritin if iron-marginal.
• Gallstones / gallbladder disease — curcumin is choleretic (stimulates bile flow). In people with active gallstones, this can trigger biliary colic by mobilizing stones into the cystic duct. Contraindicated in symptomatic gallstone disease. the user: no known gallstones, no symptoms — not a current concern, but flag if RUQ pain ever develops.
• Bleeding risk with anticoagulants — mild antiplatelet effect at high doses; case reports of bruising or INR elevation in patients on warfarin or DOACs at curcumin doses ≥1500 mg/day. Not relevant for users in this archetype.
• Theoretical: oxalate load — turmeric is high-oxalate; concentrated curcumin extracts have lower oxalate than crude turmeric. Not relevant unless on oxalate-restricted diet for kidney stones.
• Allergic reaction — rare, usually contact dermatitis with topical or hypersensitivity to ginger/turmeric family. Cross-reactive with ginger allergy.
• Reproductive / pregnancy — curcumin is uterotonic at high doses (traditional Indian/Ayurvedic emmenagogue); pregnant women should avoid supplemental doses. Not relevant for users in this archetype; flag for partner.

Specific watch periods:

• First 8-12 weeks: check ALT/AST/ALP if any GI symptoms or fatigue develops. Most DILI cases present in the 4-12 week window.
• 6 months in: routine ALT/AST + ferritin recheck.
• Annually: lipid panel, fasting glucose (should improve, not worsen — but verify).