diff --git a/lib/screens/add_supplement_screen.dart b/lib/screens/add_supplement_screen.dart
index 6847afe..b5a2f51 100644
--- a/lib/screens/add_supplement_screen.dart
+++ b/lib/screens/add_supplement_screen.dart
@@ -557,21 +557,24 @@ class _AddSupplementScreenState extends State<AddSupplementScreen> {
   void _saveSupplement() async {
     if (_formKey.currentState!.validate()) {
       // Validate that we have at least one ingredient with name and amount
-      final validIngredients = _ingredientControllers.where((controller) =>
-        controller.nameController.text.trim().isNotEmpty &&
-        (double.tryParse(controller.amountController.text) ?? 0) > 0
-      ).map((controller) => Ingredient(
-        name: controller.nameController.text.trim(),
-        amount: double.tryParse(controller.amountController.text) ?? 0.0,
-        unit: controller.selectedUnit,
-        syncId: const Uuid().v4(),
-        lastModified: DateTime.now(),
-      )).toList();
+      final validIngredients = _ingredientControllers
+          .where((controller) =>
+              controller.nameController.text.trim().isNotEmpty &&
+              (double.tryParse(controller.amountController.text) ?? 0) > 0)
+          .map((controller) => Ingredient(
+                name: controller.nameController.text.trim(),
+                amount: double.tryParse(controller.amountController.text) ?? 0.0,
+                unit: controller.selectedUnit,
+                syncId: const Uuid().v4(),
+                lastModified: DateTime.now(),
+              ))
+          .toList();
 
       if (validIngredients.isEmpty) {
         ScaffoldMessenger.of(context).showSnackBar(
           const SnackBar(
-            content: Text('Please add at least one ingredient with name and amount'),
+            content:
+                Text('Please add at least one ingredient with name and amount'),
           ),
         );
         return;
@@ -580,14 +583,20 @@ class _AddSupplementScreenState extends State<AddSupplementScreen> {
       final supplement = Supplement(
         id: widget.supplement?.id,
         name: _nameController.text.trim(),
-        brand: _brandController.text.trim().isNotEmpty ? _brandController.text.trim() : null,
+        brand: _brandController.text.trim().isNotEmpty
+            ? _brandController.text.trim()
+            : null,
         ingredients: validIngredients,
         numberOfUnits: int.parse(_numberOfUnitsController.text),
         unitType: _selectedUnitType,
         frequencyPerDay: _frequencyPerDay,
         reminderTimes: _reminderTimes,
-        notes: _notesController.text.trim().isNotEmpty ? _notesController.text.trim() : null,
+        notes: _notesController.text.trim().isNotEmpty
+            ? _notesController.text.trim()
+            : null,
         createdAt: widget.supplement?.createdAt ?? DateTime.now(),
+        syncId: widget.supplement?.syncId, // Preserve syncId on update
+        lastModified: DateTime.now(), // Always update lastModified on save
       );
 
       final provider = context.read<SupplementProvider>();
diff --git a/lib/services/database_sync_service.dart b/lib/services/database_sync_service.dart
index 9ba1504..bc4b572 100644
--- a/lib/services/database_sync_service.dart
+++ b/lib/services/database_sync_service.dart
@@ -27,40 +27,40 @@ enum RecordSyncStatus {
 
 class DatabaseSyncService {
   static const String _remoteDbFileName = 'supplements.db';
-  
+
   // SharedPreferences keys for persistence
   static const String _keyServerUrl = 'sync_server_url';
   static const String _keyUsername = 'sync_username';
   static const String _keyPassword = 'sync_password';
   static const String _keyRemotePath = 'sync_remote_path';
-  
+
   Client? _client;
   String? _remotePath;
-  
+
   // Store configuration values
   String? _serverUrl;
-  String? _username; 
+  String? _username;
   String? _password;
   String? _configuredRemotePath;
-  
+
   final DatabaseHelper _databaseHelper = DatabaseHelper.instance;
-  
+
   SyncStatus _status = SyncStatus.idle;
   String? _lastError;
   DateTime? _lastSyncTime;
-  
+
   // Getters
   SyncStatus get status => _status;
   String? get lastError => _lastError;
   DateTime? get lastSyncTime => _lastSyncTime;
   bool get isConfigured => _client != null;
-  
+
   // Configuration getters
   String? get serverUrl => _serverUrl;
   String? get username => _username;
   String? get password => _password;
   String? get remotePath => _configuredRemotePath;
-  
+
   // Callbacks for UI updates
   Function(SyncStatus)? onStatusChanged;
   Function(String)? onError;
@@ -78,11 +78,11 @@ class DatabaseSyncService {
       _username = prefs.getString(_keyUsername);
       _password = prefs.getString(_keyPassword);
       _configuredRemotePath = prefs.getString(_keyRemotePath);
-      
+
       // If we have saved configuration, set up the client
       if (_serverUrl != null && _username != null && _password != null && _configuredRemotePath != null) {
         _remotePath = _configuredRemotePath!.endsWith('/') ? _configuredRemotePath : '$_configuredRemotePath/';
-        
+
         _client = newClient(
           _serverUrl!,
           user: _username!,
@@ -123,9 +123,9 @@ class DatabaseSyncService {
     _username = username;
     _password = password;
     _configuredRemotePath = remotePath;
-    
+
     _remotePath = remotePath.endsWith('/') ? remotePath : '$remotePath/';
-    
+
     _client = newClient(
       serverUrl,
       user: username,
@@ -139,7 +139,7 @@ class DatabaseSyncService {
 
   Future<bool> testConnection() async {
     if (_client == null) return false;
-    
+
     try {
       await _client!.ping();
       return true;
@@ -157,26 +157,26 @@ class DatabaseSyncService {
     }
 
     _setStatus(SyncStatus.downloading);
-    
+
     try {
       // Step 1: Download remote database (if it exists)
       final remoteDbPath = await _downloadRemoteDatabase();
-      
+
       // Step 2: Merge databases
       _setStatus(SyncStatus.merging);
       await _mergeDatabases(remoteDbPath);
-      
+
       // Step 3: Upload merged database
       _setStatus(SyncStatus.uploading);
       await _uploadLocalDatabase();
-      
+
       // Step 4: Cleanup - for now we'll skip cleanup to avoid file issues
       // TODO: Implement proper cleanup once file operations are working
-      
+
       _lastSyncTime = DateTime.now();
       _setStatus(SyncStatus.completed);
       onSyncCompleted?.call();
-      
+
     } catch (e) {
       _lastError = e.toString();
       _setStatus(SyncStatus.error);
@@ -193,35 +193,35 @@ class DatabaseSyncService {
       // Check if remote database exists
       final files = await _client!.readDir(_remotePath!);
       final remoteDbExists = files.any((file) => file.name == _remoteDbFileName);
-      
+
       if (!remoteDbExists) {
         if (kDebugMode) {
           print('SupplementsLog: No remote database found, will upload local database');
         }
         return null;
       }
-      
+
       if (kDebugMode) {
         print('SupplementsLog: Remote database found, downloading...');
       }
-      
+
       // Download the remote database
       final remoteDbBytes = await _client!.read('$_remotePath$_remoteDbFileName');
-      
+
       // Create a temporary file path for the downloaded database
       final tempDir = await getDatabasesPath();
       final tempDbPath = join(tempDir, 'remote_supplements.db');
-      
+
       // Write the downloaded database to a temporary file
       final tempFile = io.File(tempDbPath);
       await tempFile.writeAsBytes(remoteDbBytes);
-      
+
       if (kDebugMode) {
         print('SupplementsLog: Downloaded remote database (${remoteDbBytes.length} bytes) to: $tempDbPath');
       }
-      
+
       return tempDbPath;
-      
+
     } catch (e) {
       if (kDebugMode) {
         print('SupplementsLog: Failed to download remote database: $e');
@@ -237,20 +237,20 @@ class DatabaseSyncService {
       }
       return;
     }
-    
+
     if (kDebugMode) {
       print('SupplementsLog: Starting database merge from: $remoteDbPath');
     }
-    
+
     final localDb = await _databaseHelper.database;
     final remoteDb = await openDatabase(remoteDbPath, readOnly: true);
-    
+
     try {
       // Check what tables exist in remote database
       if (kDebugMode) {
         final tables = await remoteDb.rawQuery("SELECT name FROM sqlite_master WHERE type='table'");
         print('SupplementsLog: Remote database tables: ${tables.map((t) => t['name']).toList()}');
-        
+
         // Count records in each table
         try {
           final supplementCount = await remoteDb.rawQuery('SELECT COUNT(*) as count FROM supplements');
@@ -258,7 +258,7 @@ class DatabaseSyncService {
         } catch (e) {
           print('SupplementsLog: Error counting supplements: $e');
         }
-        
+
         try {
           final intakeCount = await remoteDb.rawQuery('SELECT COUNT(*) as count FROM supplement_intakes');
           print('SupplementsLog: Remote intakes count: ${intakeCount.first['count']}');
@@ -266,17 +266,17 @@ class DatabaseSyncService {
           print('SupplementsLog: Error counting intakes: $e');
         }
       }
-      
+
       // Merge supplements
       await _mergeSupplements(localDb, remoteDb);
-      
+
       // Merge intakes
       await _mergeIntakes(localDb, remoteDb);
-      
+
       if (kDebugMode) {
         print('SupplementsLog: Database merge completed successfully');
       }
-      
+
     } finally {
       await remoteDb.close();
     }
@@ -286,52 +286,62 @@ class DatabaseSyncService {
     if (kDebugMode) {
       print('SupplementsLog: Starting supplement merge...');
     }
-    
+
     // Get all supplements from remote database
     final remoteMaps = await remoteDb.query('supplements');
-    final remoteSupplements = remoteMaps.map((map) => Supplement.fromMap(map)).toList();
-    
+    final remoteSupplements =
+        remoteMaps.map((map) => Supplement.fromMap(map)).toList();
+
     if (kDebugMode) {
-      print('SupplementsLog: Found ${remoteSupplements.length} supplements in remote database');
+      print(
+          'SupplementsLog: Found ${remoteSupplements.length} supplements in remote database');
       for (final supplement in remoteSupplements) {
-        print('SupplementsLog: Remote supplement: ${supplement.name} (syncId: ${supplement.syncId}, deleted: ${supplement.isDeleted})');
+        print(
+            'SupplementsLog: Remote supplement: ${supplement.name} (syncId: ${supplement.syncId}, deleted: ${supplement.isDeleted})');
       }
     }
-    
+
     for (final remoteSupplement in remoteSupplements) {
       if (remoteSupplement.syncId.isEmpty) {
         if (kDebugMode) {
-          print('SupplementsLog: Skipping supplement ${remoteSupplement.name} - no syncId');
+          print(
+              'SupplementsLog: Skipping supplement ${remoteSupplement.name} - no syncId');
         }
         continue;
       }
-      
+
       // Find existing supplement by syncId
       final existingMaps = await localDb.query(
         'supplements',
         where: 'syncId = ?',
         whereArgs: [remoteSupplement.syncId],
       );
-      
+
       if (existingMaps.isEmpty) {
         // New supplement from remote - insert it
         if (!remoteSupplement.isDeleted) {
-          final supplementToInsert = remoteSupplement.copyWith(id: null);
-          await localDb.insert('supplements', supplementToInsert.toMap());
+          // Manually create a new map without the id to ensure it's null
+          final mapToInsert = remoteSupplement.toMap();
+          mapToInsert.remove('id');
+          await localDb.insert('supplements', mapToInsert);
           if (kDebugMode) {
-            print('SupplementsLog: ✓ Inserted new supplement: ${remoteSupplement.name}');
+            print(
+                'SupplementsLog: ✓ Inserted new supplement: ${remoteSupplement.name}');
           }
         } else {
           if (kDebugMode) {
-            print('SupplementsLog: Skipping deleted supplement: ${remoteSupplement.name}');
+            print(
+                'SupplementsLog: Skipping deleted supplement: ${remoteSupplement.name}');
           }
         }
       } else {
         // Existing supplement - update if remote is newer
         final existingSupplement = Supplement.fromMap(existingMaps.first);
-        
-        if (remoteSupplement.lastModified.isAfter(existingSupplement.lastModified)) {
-          final supplementToUpdate = remoteSupplement.copyWith(id: existingSupplement.id);
+
+        if (remoteSupplement.lastModified
+            .isAfter(existingSupplement.lastModified)) {
+          final supplementToUpdate =
+              remoteSupplement.copyWith(id: existingSupplement.id);
           await localDb.update(
             'supplements',
             supplementToUpdate.toMap(),
@@ -339,16 +349,18 @@ class DatabaseSyncService {
             whereArgs: [existingSupplement.id],
           );
           if (kDebugMode) {
-            print('SupplementsLog: ✓ Updated supplement: ${remoteSupplement.name}');
+            print(
+                'SupplementsLog: ✓ Updated supplement: ${remoteSupplement.name}');
           }
         } else {
           if (kDebugMode) {
-            print('SupplementsLog: Local supplement ${remoteSupplement.name} is newer, keeping local version');
+            print(
+                'SupplementsLog: Local supplement ${remoteSupplement.name} is newer, keeping local version');
           }
         }
       }
     }
-    
+
     if (kDebugMode) {
       print('SupplementsLog: Supplement merge completed');
     }
@@ -358,15 +370,15 @@ class DatabaseSyncService {
     if (kDebugMode) {
       print('SupplementsLog: Starting intake merge...');
     }
-    
+
     // Get all intakes from remote database
     final remoteMaps = await remoteDb.query('supplement_intakes');
     final remoteIntakes = remoteMaps.map((map) => SupplementIntake.fromMap(map)).toList();
-    
+
     if (kDebugMode) {
       print('SupplementsLog: Found ${remoteIntakes.length} intakes in remote database');
     }
-    
+
     for (final remoteIntake in remoteIntakes) {
       if (remoteIntake.syncId.isEmpty) {
         if (kDebugMode) {
@@ -374,14 +386,14 @@ class DatabaseSyncService {
         }
         continue;
       }
-      
+
       // Find existing intake by syncId
       final existingMaps = await localDb.query(
         'supplement_intakes',
         where: 'syncId = ?',
         whereArgs: [remoteIntake.syncId],
       );
-      
+
       if (existingMaps.isEmpty) {
         // New intake from remote - need to find local supplement ID
         if (!remoteIntake.isDeleted) {
@@ -408,7 +420,7 @@ class DatabaseSyncService {
       } else {
         // Existing intake - update if remote is newer
         final existingIntake = SupplementIntake.fromMap(existingMaps.first);
-        
+
         if (remoteIntake.lastModified.isAfter(existingIntake.lastModified)) {
           final intakeToUpdate = remoteIntake.copyWith(id: existingIntake.id);
           await localDb.update(
@@ -427,7 +439,7 @@ class DatabaseSyncService {
         }
       }
     }
-    
+
     if (kDebugMode) {
       print('SupplementsLog: Intake merge completed');
     }
@@ -440,20 +452,20 @@ class DatabaseSyncService {
       where: 'id = ?',
       whereArgs: [remoteSupplementId],
     );
-    
+
     if (remoteSupplementMaps.isEmpty) return null;
-    
+
     final remoteSupplement = Supplement.fromMap(remoteSupplementMaps.first);
-    
+
     // Find the local supplement with the same syncId
     final localSupplementMaps = await localDb.query(
       'supplements',
       where: 'syncId = ?',
       whereArgs: [remoteSupplement.syncId],
     );
-    
+
     if (localSupplementMaps.isEmpty) return null;
-    
+
     return localSupplementMaps.first['id'] as int;
   }
 
@@ -462,27 +474,27 @@ class DatabaseSyncService {
       // Get the local database path
       final localDb = await _databaseHelper.database;
       final dbPath = localDb.path;
-      
+
       if (kDebugMode) {
         print('SupplementsLog: Reading database from: $dbPath');
       }
-      
+
       // Read the database file
       final dbFile = io.File(dbPath);
       if (!await dbFile.exists()) {
         throw Exception('Database file not found at: $dbPath');
       }
-      
+
       final dbBytes = await dbFile.readAsBytes();
-      
+
       if (kDebugMode) {
         print('SupplementsLog: Database file size: ${dbBytes.length} bytes');
       }
-      
+
       if (dbBytes.isEmpty) {
         throw Exception('Database file is empty');
       }
-      
+
       // Ensure remote directory exists
       try {
         await _client!.readDir(_remotePath!);
@@ -492,15 +504,15 @@ class DatabaseSyncService {
         }
         await _client!.mkdir(_remotePath!);
       }
-      
+
       // Upload the database file
       final remoteUrl = '$_remotePath$_remoteDbFileName';
       await _client!.write(remoteUrl, dbBytes);
-      
+
       if (kDebugMode) {
         print('SupplementsLog: Successfully uploaded database (${dbBytes.length} bytes) to: $remoteUrl');
       }
-      
+
     } catch (e) {
       if (kDebugMode) {
         print('SupplementsLog: Failed to upload database: $e');