Normally,
side effects disappear if you continue treatment and keep to your recommended diet. Don’t be alarmed by this list of side effects. You may not experience any of them. Most patients experienced only one episode. Consult with your doctor on any side effects that are of concern to you.

Abdominal
discomfort or pain
Anxiety
Arthritis
Back pain
Diarrhea, generally mild and goes away
Dizziness
Earache
Fatigue
Fatty or oily stools - 20% of patients
Fecal
urgency or incontinence - 22.1% of patients
Flu
Gas
with fecal discharge, generally mild and goes away - 23.9% of patients
Gum
problems
Headache
Increased defecation
Incontinence (fecal) - 7.7% of patients
leaky stools in some patients temporarily

Menstrual problems
Muscle pain
Nausea
Rectal discomfort or pain

Respiratory
tract infections
Skin rash
Sleep problems
Stomach cramps
Tooth problems
Urgency to have a bowel movement
Urinary tract infections
Vaginal inflammation
Vomiting

Less common side effects may include dry skin, ear/nose/throat problems and joint disorders.

Side effects that usually occur after the first year of treatment with Xenical include depression, leg pain, swollen feet and tendonitis.

Due, to the presence of undigested fat, it’s natural for the bowel movement to change color. It may be clear to orange or brown. These bowel changes are a natural effect of blocking the fat from being absorbed and indicates the xenical is working.

There’s an unpleasant cost of going off your diet. Side effects are worse with more fat. The more fat you eat, the more side effects you can suffer. Keep to your recommended diet of meals containing no more than 30% fat.