i am writing this review after 4 weeks of uses. its effect on body is drastic, but make sure you are not on any age restricted condition because you may gain 2 or 3 kgs initially because of water retention in your muscles. if you are looking for a ceratine as a bignner i highly recommend you to use it. when it comes to any type of harm to body it is purely safe even if sometimes you misses to take adequate water, there is no stomach ache and yellow pee..... but you should take atleast 5 litr...