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Weight-loss medicines: orlistat, what it can and can't do, and a health warning

Weight-loss medicines: orlistat, what it can and can't do, and a health warning

The short version: the only medicine in this section with a Spanish licence is orlistat 120 mg, and it is meant for adults with a body mass index (BMI) of 30 or more, or 28 or more with weight-related health problems, alongside a diet. Nothing sold here will make you lose weight on its own. And do not take Lida Daidaihua: the Spanish medicines agency found a withdrawn drug in it. In Spain, prescription-only medicines may not be sold online, and customs can hold a parcel that contains them. We do not check prescriptions: talk to your doctor before you order.

Obesity is a long-term medical condition rather than a failure of willpower, and treating it rests on food, physical activity and, for some people, medication. Medicines do help, but by less than online adverts suggest. This page sets out what orlistat does, what it achieved in trials, and how to spot slimming products you should steer clear of.

What this section contains

Xenical Generic (orlistat 120 mg): the active ingredient of Xenical, licensed in Spain on prescription for obesity. We sell it in boxes of 10 to 180 capsules and don't name the manufacturer. At three capsules a day, a box of 10 lasts just over three days; the 12-week trial period set out in the product information needs about 250.

Lida Daidaihua: don't buy it, don't take it. It is sold as a “natural” herbal slimming aid, but the Spanish medicines agency (AEMPS) found undeclared sibutramine in it. Sibutramine was withdrawn across the EU in 2010 because it raises heart rate and blood pressure and can lead to arrhythmias, heart attacks and strokes. The AEMPS warning (20 November 2020, reference ICM (MI) 5/2020) reports a case that ended in death. If you see it advertised on any website, do not order it. If you have taken it and notice palpitations or chest pain, call 112. AEMPS notice (in Spanish).

What orlistat can realistically do

Orlistat blocks some of the enzymes that digest fat, so roughly a third of the fat in a meal passes through unabsorbed. It does not curb your appetite or speed up your metabolism.

Everyone in the trials was on a reduced-calorie diet. Those taking orlistat lost about 3 kg more over a year than those on diet alone.
If you have not lost at least 5% of your starting weight after 12 weeks, the product information says to stop: it is unlikely to work for you.
One capsule goes with each main meal that contains fat, up to three a day. Taking more does not mean losing more.
Fatty meals bring oily spotting, wind, urgency and loose, oily stools. That is the signal that the meal had too much fat in it.

Trial figures, diet advice and a BMI calculator are on the orlistat 120 mg page.

Who shouldn't take it, or should ask first

It is not for under-18s, breastfeeding women, or anyone with chronic malabsorption or cholestasis; in pregnancy, only on a doctor's advice. Talk to a doctor first if you take ciclosporin, levothyroxine, blood thinners such as warfarin or acenocoumarol (Sintrom, widely used in Spain), epilepsy medicines or HIV treatment, or if you have chronic kidney disease or type 2 diabetes, as other medicines may need adjusting.

Is that slimming product trustworthy?

Think of a product you have seen advertised and tick whatever applies. This flags warning signs; it cannot test the product.

It promises a lot of weight loss in a few weeks, with no diet It is sold as “100% natural” or “herbal”, yet works fast The label is not in Spanish, or names no manufacturer It is only sold on websites or social media, never in pharmacies Taking it gives you palpitations, jitters, insomnia or high blood pressure It appears in an AEMPS warning

Other options a doctor may consider

Orlistat 60 mg (Alli and similar brands) is sold without a prescription in Spain, but only in pharmacies, for adults with a BMI of 28 or more. Prescription injections are also licensed for obesity, such as semaglutide (Wegovy), liraglutide (Saxenda) and tirzepatide (Mounjaro); a doctor prescribes and monitors them, and we don't sell them. For severe obesity, surgery is another option. Which of these makes sense depends on your weight, your health and what you have already tried.

Prescription and delivery

Orlistat 120 mg can be prescribed by your GP (médico de familia) at the centro de salud or by an endocrinologist, publicly or privately. Expect to be weighed and measured and asked about blood pressure, diabetes and your other medicines. The Spanish health system does not fund it, so you pay the full price. Our orders go by post or courier under our delivery conditions.

Common questions

Can I buy orlistat without a prescription in Spain?

Not the 120 mg strength: it is prescription-only and may not be sold online. The 60 mg strength is sold without a prescription, but only in pharmacies.

How much weight will I lose on orlistat?

In trials, about 3 kg more over a year than with diet alone. Most of the weight comes off through the diet; orlistat adds to it.

Does orlistat work if I don't change what I eat?

No. It was always studied alongside a reduced-calorie diet, and with very fatty meals the digestive side effects become hard to live with.

Isn't Lida Daidaihua a natural product?

That is how it is sold, but the AEMPS found sibutramine in it, a drug withdrawn because of its risks to the heart, and reported a death. Don't take it.

Does orlistat affect the contraceptive pill?

If it gives you severe diarrhoea, the pill may be absorbed less well. In that case, use condoms as well.

Sources: Spanish product information for Xenical 120 mg and Alli 60 mg (CIMA, AEMPS); EMA product information for Xenical; AEMPS notice ICM (MI) 5/2020 on Li Da Daidaihua (20.11.2020); BIFIMED, Spanish Ministry of Health. General information only; it does not replace a consultation. In Spain, prescription-only medicines may not be sold online, and customs can hold a parcel that contains them. We do not check prescriptions: talk to your doctor before you order.