There are a variety of products out there ranging is cost and quality.
Prestige labs is one of the best ones out there! these are the ones I use for myself and believe strongly in, that I know they will work everyone else too!
You are not required to use supplements it is all for personal preference but what they do is fill in the gaps of nutrients in your body or struggle of lifestyle balance. From helping you to hit a deeper sleep and stay asleep longer, to battling night time cravings, fat burners, non-jittery pre-workouts, and post workout recovery drinks. By taking supplements it is a quick start for your system and it will help you to reach your goals faster.
I would love all women to be on Burn AM, the best thermogenic fat burner around. And all men should be on Test Storm. Both of these products help to burn stubborn body fat and help maintain muscle mass along with regular exercise and a balanced diet.