These vitamins do work ... you do feel more energized through out the day. But if you happen to be caffeine sensitive, as I am, I would think twice about trying this product. I took them for approximately 2 months and I noticed that I was having more hot flashes (going through peri menopause) than I normally do. When I talked to my doctor, she told me to avoid all caffeine products. This meant that I would have to stop these vitamins, so I quit taking them and within 2 days I developed the most awful nauseating headaches I have ever had. The headaches lasted for about 4 days while my body went through caffeine withdrawals. The good news is my hot flashed subsided once this product was out of my system.
If you are caffeine sensitive .... or close to menopause ... think twice before taking this product.