diff --git a/frontend/js/db.js b/frontend/js/db.js
index 95140a0..a90f4fd 100644
--- a/frontend/js/db.js
+++ b/frontend/js/db.js
@@ -1153,24 +1153,7 @@ async function runMigrations() {
   await addSuppCol("omega6_mg", "REAL");     // омега-6
   await addSuppCol("omega9_mg", "REAL");     // омега-9
 
-  // Deduplicate products: keep lowest id per name_lower, reassign refs, delete dupes
-  // All in bulk SQL — no per-row loop
-  try {
-    const dupeCount = await select("SELECT COUNT(*) as cnt FROM products WHERE name_lower IS NOT NULL AND id NOT IN (SELECT MIN(id) FROM products WHERE name_lower IS NOT NULL GROUP BY name_lower)");
-    if (dupeCount[0].cnt > 0) {
-      // Reassign food_log to kept (MIN) id
-      await execute(`UPDATE food_log SET product_id = (
-        SELECT MIN(p2.id) FROM products p2 WHERE p2.name_lower = (SELECT p3.name_lower FROM products p3 WHERE p3.id = food_log.product_id)
-      ) WHERE product_id IN (SELECT id FROM products WHERE name_lower IS NOT NULL AND id NOT IN (SELECT MIN(id) FROM products WHERE name_lower IS NOT NULL GROUP BY name_lower))`);
-      // Reassign recipe_ingredients
-      await execute(`UPDATE recipe_ingredients SET product_id = (
-        SELECT MIN(p2.id) FROM products p2 WHERE p2.name_lower = (SELECT p3.name_lower FROM products p3 WHERE p3.id = recipe_ingredients.product_id)
-      ) WHERE product_id IN (SELECT id FROM products WHERE name_lower IS NOT NULL AND id NOT IN (SELECT MIN(id) FROM products WHERE name_lower IS NOT NULL GROUP BY name_lower))`);
-      // Delete dupes
-      await execute("DELETE FROM products WHERE name_lower IS NOT NULL AND id NOT IN (SELECT MIN(id) FROM products WHERE name_lower IS NOT NULL GROUP BY name_lower)");
-      console.log(`[db.js] Deduplicated ${dupeCount[0].cnt} products`);
-    }
-  } catch (e) { console.error("[db.js] dedup error:", e); }
+  // Product dedup handled in Rust import_seed_products (UNIQUE INDEX on name_lower+source+store_id)
 
   console.log("[db.js] recipe migrations done, checking seq repair...");
 
diff --git a/src-tauri/src/lib.rs b/src-tauri/src/lib.rs
index dc2bba9..d8e10d6 100644
--- a/src-tauri/src/lib.rs
+++ b/src-tauri/src/lib.rs
@@ -152,8 +152,51 @@ fn import_seed_products(app: tauri::AppHandle) -> Result<String, String> {
     let seed_str = seed_path.to_str().unwrap_or_default().to_string();
     main_db.execute("ATTACH DATABASE ?1 AS seed", rusqlite::params![seed_str]).map_err(|e| e.to_string())?;
 
-    // Bulk INSERT new products from seed (one SQL statement, not a loop)
     main_db.execute("BEGIN", []).map_err(|e| e.to_string())?;
+
+    // Create index for fast lookups during dedup and insert
+    let _ = main_db.execute_batch(
+        "CREATE INDEX IF NOT EXISTS idx_products_name_lower ON main.products(name_lower);"
+    );
+
+    // Dedup existing products by (name_lower, source, store_id).
+    // Reassign food_log and recipe_ingredients refs to kept (MIN id) product, then delete dupes.
+    let _ = main_db.execute_batch(
+        "UPDATE food_log SET product_id = (
+           SELECT MIN(p2.id) FROM products p2
+           WHERE p2.name_lower = (SELECT p3.name_lower FROM products p3 WHERE p3.id = food_log.product_id)
+             AND p2.source = (SELECT p3.source FROM products p3 WHERE p3.id = food_log.product_id)
+             AND COALESCE(p2.store_id,'') = COALESCE((SELECT p3.store_id FROM products p3 WHERE p3.id = food_log.product_id),'')
+         ) WHERE product_id NOT IN (
+           SELECT MIN(id) FROM products WHERE name_lower IS NOT NULL
+           GROUP BY name_lower, source, COALESCE(store_id,'')
+         );
+
+         UPDATE recipe_ingredients SET product_id = (
+           SELECT MIN(p2.id) FROM products p2
+           WHERE p2.name_lower = (SELECT p3.name_lower FROM products p3 WHERE p3.id = recipe_ingredients.product_id)
+             AND p2.source = (SELECT p3.source FROM products p3 WHERE p3.id = recipe_ingredients.product_id)
+             AND COALESCE(p2.store_id,'') = COALESCE((SELECT p3.store_id FROM products p3 WHERE p3.id = recipe_ingredients.product_id),'')
+         ) WHERE product_id NOT IN (
+           SELECT MIN(id) FROM products WHERE name_lower IS NOT NULL
+           GROUP BY name_lower, source, COALESCE(store_id,'')
+         );
+
+         DELETE FROM products WHERE name_lower IS NOT NULL
+           AND id NOT IN (
+             SELECT MIN(id) FROM products WHERE name_lower IS NOT NULL
+             GROUP BY name_lower, source, COALESCE(store_id,'')
+           );"
+    );
+
+    // Create UNIQUE index to prevent future duplicates
+    let _ = main_db.execute_batch(
+        "CREATE UNIQUE INDEX IF NOT EXISTS idx_products_dedup
+           ON main.products(name_lower, source, COALESCE(store_id, ''))
+           WHERE name_lower IS NOT NULL;"
+    );
+
+    // Bulk INSERT new products from seed (INSERT OR IGNORE now works with unique index)
     let inserted = main_db.execute(
         "INSERT OR IGNORE INTO main.products (
             name, brand, kcal_per_100g, protein_per_100g, fat_per_100g,
@@ -173,10 +216,9 @@ fn import_seed_products(app: tauri::AppHandle) -> Result<String, String> {
         []
         ).map_err(|e| e.to_string())?;
 
-    // Create indexes for fast name_lower lookups (critical: without this UPDATE takes 60s+)
+    // Seed index for fast UPDATE lookups
     let _ = main_db.execute_batch(
-        "CREATE INDEX IF NOT EXISTS idx_products_name_lower ON main.products(name_lower);
-         CREATE INDEX IF NOT EXISTS idx_seed_name_lower ON seed.products(name_lower);"
+        "CREATE INDEX IF NOT EXISTS idx_seed_name_lower ON seed.products(name_lower);"
     );
 
     // Update KBJU + micronutrients for existing store products (seed already attached above)