If you have started orlistat, or you are considering it, you have probably come across two separate questions. The first is practical: which vitamins do you need to take alongside it, and when. The second is about the medicine itself: is Xenical just a branded version of orlistat, and if so, which one should you actually buy. This guide answers both, with UK specific dosing and eligibility information rather than generic marketing copy.
What Does Orlistat Do?
Orlistat is a lipase inhibitor. It works in your gut, blocking the enzymes that break down dietary fat so that roughly one third of the fat in a meal passes through your body unabsorbed instead of being digested. It does not suppress your appetite or act on your brain the way some other weight loss medicines do, it only affects fat you have actually eaten. That is why it only works alongside a reduced-calorie, lower-fat diet, if you eat very little fat, there is very little for it to block, and if you eat a lot of fat, you are more likely to notice the gastrointestinal side effects.
Why Orlistat Affects Your Vitamin Levels
Vitamins A, D, E and K are fat-soluble, meaning your body absorbs them alongside dietary fat, using many of the same pathways orlistat blocks.Taking orlistat over time can reduce how much of these vitamins you absorb from food, so a multivitamin supplement may be recommended to help maintain adequate vitamin int
Which Vitamins to Take with Orlistat
Look for a daily multivitamin that specifically contains vitamins A, D, E and K. If your doctor or pharmacist recommends a multivitamin while you are taking orlistat, choose one that contains vitamins A, D, E and K, and follow the advice on when to take it.
Orlistat and Vitamin D Specifically
Orlistat can reduce the absorption of vitamin D because it is fat-soluble. If you take a separate vitamin D supplement, ask your doctor or pharmacist how to time it with orlistat.
When to Take Your Multivitamin
Take your multivitamin at least 2 hours before or after an orlistat dose. In practice, if you take levothyroxine, tell your doctor or pharmacist before starting orlistat because orlistat can affect its absorption.
Is Xenical the Same as Orlistat?
Yes, in the sense that matters clinically. Orlistat is the generic name for the active ingredient. Xenical is Roche's branded version of orlistat 120mg. Generic orlistat 120mg, sold under its ingredient name, contains the exact same active ingredient at the exact same dose.
This is the same relationship as paracetamol and Panadol, or ibuprofen and Nurofen, a licensed generic medicine has to demonstrate it works the same way as the branded original before it can be sold.
Orlistat vs Xenical vs Alli: Which One Is Recommended to Buy?
This depends on what you are choosing between, since it is not really a three-way comparison, it is two separate questions.
Generic orlistat 120mg versus branded Xenical 120mg is a straightforward one. They are the same medicine at the same dose, so this comes down to budget and whether you have a preference for the branded product. Neither is more effective than the other.
Alli contains the same active ingredient, orlistat, but at a lower 60mg dose. It is available without a prescription under the supervision of a pharmacist. Whether that suits you better than the 120mg strength depends on your BMI, your goals, and how your body responds, which is exactly what your online consultation is there to assess.
| Product | Strength | Prescription Status | 4 Week Price* |
|---|---|---|---|
| Generic Orlistat | 120mg | Prescription only | From £29.69 |
| Xenical | 120mg (branded) | Prescription only | From £38.69 |
| Alli | 60mg | Lower strength option | From £26.09 |
*Prices shown with EDM10 discount code applied where stated on the live site. Prices are updated regularly and may change.
Who Can Take Orlistat?
Orlistat and Xenical are typically prescribed for adults with a BMI of 30 or above, or a BMI of 28 or above alongside a weight-related risk factor such as type 2 diabetes, high blood pressure, high cholesterol or sleep apnoea.
People from some ethnic groups may have a higher risk of weight-related health problems at a lower BMI, but the standard BMI criteria for orlistat remain 30 or above, or 28 or above with associated risk factors
Alli, the lower strength option, is generally available to adults with a BMI of 28 or above without needing an existing weight-related condition, though EverydayMeds still confirms suitability through a clinical assessment.
If you have not lost at least 5% of your starting weight after 12 weeks, your treatment should be reviewed to decide whether continuing orlistat is appropriate.
Orlistat is not the only prescription option for weight management. If it is not suitable for you, or you'd rather explore an injectable option, our Weight Loss Hub covers the full range of treatments we offer, including Mounjaro.
Other Things to Know
Side Effects
The most common side effects affect the digestive system. They include oily or fatty stools, oily spotting, increased wind and more frequent or urgent bowel movements. These effects are more likely with high-fat meals and may improve when you reduce the amount of fat in your diet.
Seek medical advice promptly for severe or persistent abdominal pain, or for signs of liver problems such as yellowing skin or eyes, dark urine, or persistent nausea, these are rare but should never be ignored.
Missed Doses
If you miss a dose and remember within about an hour of finishing your meal, you can still take it. If more time has passed, skip that dose and take your next one as normal with your next meal as usual. Do not take two doses at the same time.
Buying Orlistat, Xenical or Alli from EverydayMeds
EverydayMeds supplies generic orlistat 120mg, branded Xenical 120mg and Alli 60mg, dispensed through our GPhC-registered UK pharmacy following an online clinical assessment.
A UK licensed prescriber reviews your BMI, medical history and current medication before confirming which option is suitable, so nothing is dispensed without that check.
Medical Disclaimer
This article is for general information only and does not replace advice from a doctor or pharmacist. Treatment suitability depends on an individual clinical assessment, which is why EverydayMeds asks health and BMI questions before dispensing orlistat, Xenical or Alli. Results and side effects vary between individuals. If you experience severe abdominal pain or symptoms of liver problems, seek medical attention promptly.
