Orlistat is a medication used to help with weight management by reducing the amount of dietary fat absorbed by the body. It is available in two main strengths, 60 mg and 120 mg, each with specific uses and considerations. This article will explore how Orlistat works and compare the two available dosages to help individuals understand which option might be suitable for their weight loss journey.
Understanding Orlistat’s Action
Orlistat works by targeting specific enzymes in the digestive system. When consumed, dietary fats are broken down by gastric and pancreatic lipases into smaller, absorbable free fatty acids and monoglycerides. Orlistat inhibits these lipase enzymes by forming a covalent bond with their active sites.
This prevents the breakdown of triglycerides, so approximately 25-30% of consumed fat remains undigested. These undigested fats pass through the digestive tract and are excreted. This mechanism creates a caloric deficit, contributing to weight loss when combined with a reduced-calorie diet and regular exercise.
Orlistat 60 mg: Over-the-Counter Option
The 60 mg dosage of Orlistat is available without a prescription and is used by adults aged 18 and older with a body mass index (BMI) of 25 or more. It is taken as one 60 mg capsule with each fat-containing meal, up to three times a day, or within one hour after the meal. If a meal is skipped or contains no fat, the dose can be omitted.
The 60 mg dose blocks approximately 25% of ingested fat, and when combined with diet, it can lead to an average weight loss of about 5% of initial body weight over 16 weeks. Common side effects are gastrointestinal and include oily spotting, fatty or oily stools, increased bowel movements, gas with discharge, and an urgent need to defecate. These effects are less pronounced if dietary fat intake is kept low, ideally less than 30% of total calories.
Orlistat 120 mg: Prescription Strength
The 120 mg dosage of Orlistat is available only by prescription and is indicated for individuals with a BMI of 30 or higher, or those with a BMI of 27 or higher who also have weight-related health conditions such as high blood pressure or diabetes. This strength is taken as one 120 mg capsule three times a day with each fat-containing meal, or up to one hour after the meal. A dose can be skipped if a meal is missed or contains very little fat.
The 120 mg dose inhibits approximately 30% of dietary fat absorption, contributing to a caloric deficit of around 200 calories per day. While it can lead to more significant weight loss than diet and exercise alone, the gastrointestinal side effects, such as oily stools and increased bowel movements, are often more intense compared to the 60 mg dose, especially if dietary fat recommendations are not followed. Rare but serious side effects can include liver damage, kidney problems, or gallstones.
Choosing the Right Dosage and Important Considerations
The choice between Orlistat 60 mg and 120 mg depends on individual health profiles and weight loss goals. The 60 mg dose is an over-the-counter option, making it more accessible for individuals seeking moderate weight loss and establishing healthier eating habits. The 120 mg dose, requiring a prescription, is recommended for those with higher BMIs or co-existing health conditions, often under closer medical supervision. The 120 mg dose blocks a slightly higher percentage of fat absorption, leading to more pronounced weight loss for some individuals. This increased efficacy also means a higher likelihood of experiencing gastrointestinal side effects.
Regardless of the dosage, Orlistat is most effective when used as part of a comprehensive weight management plan that includes a reduced-calorie, low-fat diet and regular physical activity. Maintaining a dietary fat intake of no more than 30% of total calories is recommended to minimize common gastrointestinal side effects. Because Orlistat reduces fat absorption, it also decreases the absorption of fat-soluble vitamins (Vitamins A, D, E, and K) and beta-carotene. Therefore, it is advised to take a daily multivitamin containing these fat-soluble vitamins at least two hours before or after taking Orlistat, or at bedtime.
Orlistat can interact with other medications, affecting their absorption or efficacy. For example, it reduces the absorption of levothyroxine, cyclosporine, and certain antiepileptic medications. If taking levothyroxine, it should be administered at least four hours apart from Orlistat.
Individuals taking blood thinners like warfarin should be monitored closely, as Orlistat can influence vitamin K absorption, which is involved in blood clotting. Orlistat is contraindicated for individuals with chronic malabsorption syndrome, cholestasis, or those who are pregnant or breastfeeding. Consulting a healthcare professional is recommended before starting any Orlistat dosage to ensure it is appropriate and to discuss potential interactions or contraindications.