Disclaimer: None of the information in this article constitutes medical advice. All statements are merely the opinion of the writer(s). We recommend that patients follow their doctor’s guidance in regard to prescription medication.

Dicyclomine is a generic drug used to treat Irritable Bowel Syndrome (IBS). The brand name of this drug is Bentyl. Both of these terms refer to the same active drug ingredient, so we'll use them interchangeably throughout this article.

Patients are often curious about whether dicyclomine is effective for weight loss, because there are a number of anecdotal reports suggesting so online.

In this article we’ll review published medical studies on dicyclomine to determine whether the medication is effective for weight loss.

How Does Dicyclomine Work?

Dicyclomine is prescribed for IBS because of its anticholinergic action. It’s been proven in medical studies to relax smooth muscle, and this is why it can be effective for IBS management. Patients with IBS often experience uncomfortable involuntary muscle spasms in their intestinal tract, and dicyclomine reduces the number and duration of these spasms.

Nearly all of the medical research we’ve encountered on dicyclomine is related to its effects on gastrointestinal conditions, not weight loss.

There is no logical reason to believe that the relaxation of smooth muscle would cause weight loss.

Can Dicyclomine Help With Weight Loss?

We cannot identify any clinical evidence suggesting that dicyclomine is effective for weight loss. In fact, we haven’t even come across one single medical trial testing the drug's effects on weight, or reporting weight loss as a side effect. 

Some of the misconception that dicyclomine may be effective for weight loss likely stems from the fact that IBS itself can cause weight loss, and many people with IBS are prescribed dicyclomine. But this is just a correlation and has nothing to do with the drug itself.

As an example, if someone recently diagnosed with IBS has trouble absorbing their food, and loses 15 pounds over 3 months, they may believe that the weight loss was caused by an IBS drug they're taking like dicyclomine. However, it was the patient's poor absorption of food which more likely caused the weight loss. Unintentional weight loss is actually used as a diagnostic tool for IBS, based on a medical review published in the Therapeutic Advances in Gastroenterology journal.

In general, we haven't come across much promising research on prescription drugs for weight loss. There do exist some weight loss medications with proven results, one of which we outlined in our Plenity review. Even in the case of prescription weight loss drug Plenity, we found the weight loss results to be relatively minor and unimpressive, and believe that lifestyle modifications may be a superior approach.

Dicyclomine Safety

We cannot locate much safety or toxicity research published on dicyclomine for its intended use (IBS), but "off-label" use such as taking dicyclomine for weight loss is always unsafe. When a medication is used off-label, this refers to the drug being used to treat a condition that it's not approved by the Food and Drug Administration (FDA) to treat.

One medical review found that dicyclomine is safe for adults at the typical prescribed dose of 10 milligrams (mg) to 20 mg, and that this dosage range is not harmful to the liver.

Our Weight Loss Supplement Recommendations

There exist several over-the-counter (OTC) weight loss supplements that don't require a prescription, and which have medical research backing.

We recommend dietary fiber as a safe and effective weight loss supplement, especially when combined with caloric restriction.

A landmark medical study found that moderate caloric restriction (750 calories per day below baseline) combined with dietary fiber intake (a minimum of 20 grams per day) caused an average weight loss of 16.03 pounds over 6 months. That’s a pace of 32 pounds per year of weight loss in overweight individuals simply by adding fiber to a moderately-restricted-calorie diet.

The fiber supplement we recommend is SuperGut Fiber Mix. It contains a clean and effective formulation: a blend of three different types of unflavored dietary fiber and zero additive ingredients. It can be mixed into liquids or foods. Interested consumers can buy SuperGut fiber at this link.

We recommend using two fiber mixes per day, which provides 16 g of total fiber. Diet should provide the remaining fiber necessary to meet the 20 g minimum threshold.

Medium-chain triglyceride (MCT) oil is another dietary supplement which has been shown in clinical trials to cause weight loss.

MCT oil is quickly absorbed by the body and increases metabolic rate, which causes fat loss. A meta-study on MCT oil documented weight loss of 1.12 pounds over 10 weeks. This equates to a potential annualized weight loss of 5.84 pounds with MCT oil supplementation.

We recommend Bulletproof MCT Oil as our top MCT oil product, because it has a clean and effective formulation. The only ingredient is MCT oil derived from coconuts, and the product has no questionable additives. Interested consumers can buy Bulletproof MCT Oil at this link.

The effective dose range of MCT oil for weight loss (based on the medical review) is 1.7 g to 10 g per day. Bulletproof's MCT oil provides 14 g in one tablespoon, so around two-thirds of one tablespoon should be a maximally-effective dosage.

Conclusion

We do not believe that dicyclomine is safe or effective for weight loss. It seems as though patients may consider this medication effective for weight loss due to its use as an IBS drug. IBS patients may experience weight loss due to their condition, but this weight loss doesn't appear to have anything to do with the use of dicyclomine.

Dietary fiber and MCT oil are OTC supplements that may be beneficial for overweight and obese patients seeking weight loss outcomes without any significant side effects.