Dear MJ
The L-phenylalanine (an amino acid) is only harmful if you suffer from phenylketonuria, but it will not promote weightloss. The B vitamins (niacin, riboflavin, thiamine, pyridoxine) should not be harmful, but will not promote weightloss. Caffeine is a stimulant and mild diuretic so it may help a bit for weightloss. The uva ursi is a diuretic which can cause electrolyte imbalances and dehydration if used in excess - it will make you lose mass when it increases urination, but will not cause fat loss and you will regain the weight if you drink liquids. So all in all, this is another herbal slimming pill that will not really help with weightloss and some of the ingredients have the potential to cause problems. Rather use a low-fat, energy-reduced slimming diet and plenty of exercise to lose that weight - safer, cheaper and more sensible.
Take care
DietDoc