1: Vitamin C supplements offer little benefit if already getting enough from diet.

2: Glucosamine and chondroitin may not ease joint pain as claimed.

3: Biotin supplements for hair and nail health lack scientific evidence.

4: Multivitamins may not improve overall health if a balanced diet is maintained.

5: Fish oil supplements may not benefit heart health in those already eating fish.

6: Probiotic supplements may not always improve gut health as marketed.

7: Echinacea supplements may not prevent colds as advertised.

8: Ginseng supplements may not boost energy levels as promised.

9: Wheatgrass supplements may not offer significant health benefits.