Yes you can take orlistat for weight reduction but gradual increment in dosage is advisable to minimise gastric intolerance. Starting with 60 mg twice before meals generally dont give much side effects. It is advisable to do blood investigations and obesity consultant's opinion before starting such medication.
Orlistat is lìpase inhibitor so it prevents almost 30% of fat absorption from gut. This unabsorbed fat moves to intestine and get fermented with intestinal bacteria to produce gas so loose stools, flatulence, spotting, gastric cramps,etc is common side effect. ( sometimes very embarassing for working person).
Long term treatment can cause deficiency of fat soluble vitamins like A,D,E,K.
Multivitamin supplements along with orlistat treatment is advisable.