Return to site

Orlistat for weight loss risks and benefits?

Oliver Zolman MD

· Weight loss

Search details

1) Pubmed

systematic[sb] AND (orlistat) followed by hand searches

filter: systematic MeSH Terms: orlistat


doi: 10.1016/j.jash.2017.12.002. showed orlistat at any dose decreased BP by about 1 point on both systolic and diastolic in overweight or obese men

120mg 3 x per day orlistat was found to be ineffective in very obese men with type 2 diabetes versus reducing calories alone

60 mg 3 x per day in a study ( of BMI 25 – 28 people was found to be marginally beneficial after 4 months over placebo; but had over 20% drop out rate, however imputed intention to treat analysis was done; study benefits could be halved to be conservative because of this. The study group showed 1kg extra total weight loss over placebo group, hence 0.5kg could be assumed to compensate for the bias.

In a MA of obese people it shows that there seems to be a lower total weight loss in non obese people versus obese people (BMI > 28 showing 1.5 – 4 kg total weight loss at 6 months versus above study of non-obese people showing only 0.5-1kg range) (

“The 60 mg dose has been shown to have approx 85% the efficacy of the 120 mg dose (11,12).” (

Relative reduction in total fat mass is likely roughly carried across broad baseline fat levels; so 20% body fat may be reduced by 2% if provides a 10% reduction in total fat mass, but 10% body fat by only 1% (20one opinion).


Does not cause pure fat loss (, and does not shift type of weight loss towards fat loss, weight loss is 75% fat, 25% non fat, same in placebo and intervention groups; just causes less calories to be lost; however, combining this with resistance exercise and high protein dietary intake may shift this further towards fat loss (as previously discussed in this report).

May take 6 months to reach max benefit (

Weight likely regained after stopping taking.

Over 4 months: 20% chance of oily stool, 15% urgent need to pass stool, 10% spotting oil from anal canal, 10% chance of expelling stool simultaneously with gas; a quarter of people will have these symptoms more than once in 4 months (

3% of people stop taking orlistat altogether because of side effects (

Requires to take 3 pills every day indefinitely plus vitamin pills, plus monitor vitamin status.

Fat soluble vitamin deficiencies: may induce deficiencies of vitamins A, D, E, K (

All Posts

Almost done…

We just sent you an email. Please click the link in the email to confirm your subscription!