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Orlistat – Help With Weight Loss

Getting aware about Orlistat

Orlistat is a medicine which can help one to lose weight if one is obese or overweight. It works by blocking chemicals (enzymes) in your gut which digest fat. Nearly a third of the fat that is eaten is blocked by orlistat. The undigested fat is not absorbed into the body, and is passed out with stools (faeces). The normal dose is one capsule – 120 mg, three times a day with each meal. However, one does not need to take one if there is no fat in the meal or if one misses a meal.

Knowing one’s desired weight

One can be considered obese or overweight if one is are carrying excess body fat. As an adult, one way it can be found out whether one is overweight or obese, and whether one’s health may be at risk, is by calculating one’s body mass index (BMI).

BMI is used to estimate how much of one’s body is made up of fat, and if someone’s weight is putting their health at risk. It is a measure of one’s weight related to one’s height. BMI may not be an accurate measure for people who are very muscular, because muscle weighs more than fat. In those people, a high BMI may not necessarily mean they have too much fat in their body.

Calculating BMI

One’s BMI is calculated by dividing one’s weight (in kilograms) by the square of one’s height (in metres). So, for example:

If one weighs 70 kg and is1.55 metres tall, then one’s BMI is 70/(1.55 x 1.55), which is 29.

Normal healthy BMI is 18.5 to 24.9 kg/m. In general, the more your BMI is over 25, the more overweight or obese you are, and the greater the risk to your health. If one is very overweight, the risks to one’s health may be very high.

Another way to find out if one is overweight or obese is to measure our waist circumference.

Best way to lose weight

To lose weight, the best chance of long-term success is to eat a healthy diet and, if one is able, to exercise regularly. To lose weight, one needs to be using more energy (calories) than one is taking in by eating.

There is only a limited role for medicines to help with weight loss. Orlistat is a medicine that is sometimes advised. However, it is no ‘wonder drug’; it only partially helps, and one still needs to make lifestyle changes to improve one’s diet, eat less and increase our physical activity levels to lose weight.

Effectiveness of orlistat

Studies have shown that, on average, orlistat, plus a weight-reducing diet and exercise, causes more weight loss than a weight-reducing diet and exercise alone. Some people lose 10% or more of their body weight within six months with the help of orlistat. In others, it is less effective.

One reason why orlistat may not work is that one may think that one can relax one’s weight-reducing diet, and the orlistat will ‘do it all’. This is not true. In order to lose weight one still has to eat less, and exercise regularly. We need to remember orlistat prevents only some of the fat that is eaten from being absorbed (just under a third). But, if one does not keep to a healthy weight-reducing diet, and keeps on eating more fat (chocolates, cakes, etc), the extra fat that one eat will easily cancel out the effect of the orlistat.

Time for prescribing orlistat

Orlistat is not used in everyone who wants to lose weight. It is only recommended in people over a certain BMI. For a doctor to prescribe orlistat, they also need to be sure that you have tried changing one’s diet and increasing one’s physical activity levels first.

Doctors are expected to use the following guidelines when prescribing orlistat:

Your BMI:

Must be 30 or above; or Must be 28 or above, and weight (such as diabetes

you have a medical condition that would benefit from losing or high blood pressure).

One must lose at least 5% of one’s weight by three months from starting orlistat; if not, treatment should be stopped.

Span of treatment

If one have lost 5% of your weight within three months, there is no restriction on how long orlistat may be prescribed. However, most doctors will review treatment regularly, and will decide if it is still appropriate to carry on taking orlistat. If one continues to lose weight after six months, doctor may advise that one continues to take orlistat. This may be for up to 1-2 years, or longer if one has a great deal of weight to lose.

Post treatment weight-management

After treatment is stopped, a number of people who have lost weight with the help of orlistat put weight back on because once one has lost some weight, one is more likely to keep one’s weight down if one sticks to a healthy diet, exercise regularly (if one is able), and check weight once a week.

Aftermath with orlistat

The main side-effects are caused by the fat which is passed out with one’s stools (faeces). One may get fatty smelly stools, urgency to get to the toilet, oily spotting on one’s underclothes, and excess wind. These side-effects are less likely if one eats a low-fat diet. They tend to settle with time, possibly because if they occur they remind that one should be eating a low-fat diet. Other side-effects are rare.

Who should not take orlistat?

The following people should not take orlistat:

Pregnant or breast-feeding women.

People under the age of 18.

People who have a condition where food is not absorbed properly (a malabsorption syndrome).

People with cholestasis. This is a condition where bile does not flow properly from the liver to the duodenum.

Orlistat can also interfere with the absorption of various medicines and vitamins and affect the way that they work.

For example, orlistat interferes with:






HIV & AIDS treatment

Epilepsy medicines

It may also affect how well contraceptive pills work if one gets so much diarrhoea that they don’t absorb properly.

If one takes orlistat:

If one takes the contraceptive pill and has severe diarrhoea one should use other methods of contraception in addition to the pill – for example, condoms.

Tell one’s doctor or pharmacist about other medicines that one takes, before starting on orlistat.

A multivitamin supplement should be taken at bedtime – a time when one will not be taking orlistat – to help ensure adequate vitamin intake.


Orlistat is a medicine which can help to lose weight in cases of obesity or overweight. It works by interfering with the way that fat is digested and absorbed into the body. Doctors have guidelines as to when orlistat can be prescribed. Orlistat can also be bought from pharmacies – but certain conditions apply, detailed below. If one takes orlistat, as it may possibly interfere with the absorption of some vitamins, one should take a multivitamin supplement at bedtime. If one takes any other medicines, then one’s doctor or pharmacist should be informed as orlistat can interfere with the absorption of some medicines.