Xtrathick figures and Xtrathick figures Plus are both appetite/weight-gain products, but “Plus” versions are usually marketed as a stronger or more complete formula.
Here’s the general difference people usually mean:
Product
Main Focus
Common Ingredients
What People Use It For
Xtrathick figures
Appetite stimulation
Vitamins, herbs
Helping people eat more
Xtrathick figures Plus
Appetite + body/weight support
More vitamins/minerals, herbal blends, or calorie-support ingredients
Trying to gain more overall weight or curves
