The biggest side effect is loss to the size of your wallet.
I know several people that have tried Herbalife, Isagenix, Nanci, Nutrilite, Advocare, and the newest Healthy People Co. brand of weight loss supplements.
They all weight the same or more than when they tried them.
Alli is the only over the counter weight loss product approved by the FDA.
There are only two prescription weight loss medications approved. Do you think that if any of them REALLY worked we would have a $60 billion a year industry in "weight loss" supplements?
The big three pharmaceuticals would dominate the market.
Approved or otherwise, none of these weight loss supplements guarantee anything unless you establish a healthy diet and exercise program.
So why not just establish a healthy diet and exercise program and keep your money?
You will be spending somewhere between $4 and $10 per day on a products that are not approved or guaranteed to do anything!
The only weight loss supplement I recommend is a basic multivitamin.
$120 to $300 per month would get you a premier spa membership and the positive feeling that comes from working out and feeling healthier.
All of the above mentioned diet products are "multi level marketing" or "work from home" schemes. I think these products are the worst since they exploit both the desires of people to lose weight and to make money.
Hopefully you haven't signed up yet.
I lived in a very nice area of Phoenix for a year. 90% of the "make money from home" signs along the roads were Herbalife when you called and finally got them to tell you. These companies are more concerned with profits than weight loss. As are all the MLMs.