Metamucil Berry Burst! is a fiber laxative. Its artificially flavored and rght on the package it boasts that its the #1 doctor recommended brand. It contains psyllium fiber. Although sugar free, it is not a low calorie item.
Basically you pour it into an 8 oz glass of water and mix it up. Sadly though, mixing it still doesn't dissolve all the little grains. Another problem is that the flavor is a bit diluted by the water so you get a hint of berry, but its a little washed out. Also the gritty sands that don't dissolve can choke you, especially if you don't take it with a lot of water!
Some people maye even have allergies or are sensitive to the psylium if inhailed or ingested according to the warning label.
Overall I'm not satisified. It doesn't really taste great, its sandy, and I'd rather use alternative means of getting fiber like eating apples, spinach or maybe even using a better mix fiber drink that tastes like a delicious sweetened beverage like Kellogg's All-Bran Pink Lemonade Powder Fiber Drink Mix.
In terms of helping yu stay regular I guess its mixed results, I couldn't stand a full cup of this stuff so I dumped the other half the first time. But it does seem to help - in my mind though its too expensive when there are cheaper natural, organic alternatives.
So I give Metamucil Berry Burst! the thumbs down.