I've used it once in the past with no side effects, but as far as long time well were gonna have to wait and see hahah, as for if its dangerous or not well im no M.D. but lets put it this way there is no way its healthy, your going to hear alot about it; some will say it will shrink your adrenal gland others will say it causes liver damage beyond repair whilst others will even advocate it. My personal take on it, while it may work A LITTLE i dont think its worth it and thats comming from a person who cares far to much about his body image and puts more work then he should into it and still wont even use it anymore to get that extra edge lol. To be perfectly honost the one time I used it I really found that using an extreme diet such as a keto for fat loss was WAY WAY more effective and rewarding in the end when you know you achived the losses flying solo.
But anyway if after that you still wanna take it this is how it works:
there are a couple types of different fat burners out there are some that block carb up-take, some that block fat up-take, some that surpress appetite and many others.
Hydroxycut however is whats known as a thermogenic fat burner which literally means it heats up your body in order to increase metbolism, it does so with a number of differnt ingredients all of which im not sure but some are caffine, green tea extract and (i know im going to butcher the spelling but Yohimbe which is an extract from the bark of the tree which is the active ingredient (same thing happens when you ingest/digest protiens but to a lesser extent).
Some people have said they have trouble sleeping on this product which is another downside to it.
I hope any of this info helps
Brian