What’s Hot and What’s Hype in Weight Loss Supplements

An overview of common supplements for weight loss
Dec. 30, 2014

Trying to lose weight can be challenging to say the least. It may test our patience, perseverance, and emotions. The simplest equation for weight loss = physical activity, add more vegetables, and subtract junk food.

Whether you’re trying to lose 5 pounds or 50 pounds it takes long-term dedication, healthy routines, regularly moving your body, and a positive attitude.

This may sound simple, but it can be overwhelming getting started and frustrating trying to keep it up for months on end. Just like learning to ride a bike, try taking “baby steps” to start. Some first steps may include:

  • Cutting out one soda a day and replacing it with water, unsweetened tea, or a sugar free, calorie-free drink such as Crystal Light©.
  • Taking at least one flight of stairs at work instead of the elevator.
  • Parking further away from the store or entrance to work.
  • Doing ten sit-ups and/or ten jumping jacks while watching TV.
  • Replacing potato chips with raw cut carrots, celery, or broccoli.
  • Replacing one lunch per week with a salad (be sure to include protein).
  • Eating a small high-protein breakfast such as a boiled egg, low-fat yogurt, or smoothie.
  • Doubling your vegetable portion for dinner a few nights per week and eating less starches like potatoes, rice, and pasta.

Whether you’re just getting started with some “baby steps” or you’ve been working hard at eating healthy and exercising regularly, it is easy to be tempted to try a weight loss supplement for an extra boost or to try to speed up the weight loss process.

When is it OK to start drug therapy for weight loss?

Weight loss medication is not meant for everyone. The more overweight you are the more likely that medication could help. So if you’re only trying to lose 5 pounds or flatten your tummy, then weight loss medication is not likely going to work for you. Generally, weight loss medication should be reserved for people with a high Body Mass Index (BMI of 27 or higher) and people with health problems that would benefit from weight loss (e.g., diabetes, heart disease).

Drug therapy cannot work alone! Unfortunately there is no such drug that will magically “melt away” the pounds. Drug therapy should only be a part of a program that includes healthy eating, regular physical activity, and behavior changes.

Glucomannan (also known as Lipozene©) and Other “Gut-Fillers”

There are several fiber-like dietary supplements that work similarly to “fill up” your stomach, make you feel full, and decrease your appetite. These products are frequently marketed as “fat-blockers” but clinical studies have shown that none of these products actually block fat absorption.

Numerous other studies have shown that these supplements do not cause weight loss. However, they may be beneficial in that they might decrease your appetite and keep you feeling full longer. Feeling full longer may lead to eating less calories overall, which can help you lose weight in combination with healthy eating and exercise.

Glucomannan is an insoluable (unabsorbable) dietary fiber made from the Konjac (Amorphophallus konjac) root and also marketed under the brand name Lipozene©. It absorbs water and expands in the stomach. Some studies have shown that glucomannan may decrease cholesterol and slow gastric emptying. This means it fills up your stomach and slowly leaves the stomach into the intestine making you feel full longer.

Other supplements that work similarly include guar gum, chitosan, and bean pod (Phoseolus vulgaris). Guar gum (Cyanmopsis tetragonoloba) is often used as a thickening agent in foods. When taken in capsule form it expands and thickens the contents of your stomach. Guar gum can cause serious intestinal obstruction if not taken with enough water. Because of this risk, guar gum is not generally recommended as a weight loss aid. Chitosan is made from the exoskeletons of shellfish, so people with shellfish allergies should avoid chitosan.

Bean pod (Phoseolus vulgaris) supplements are made from extracts of white kidney beans. It is thought that bean pod supplements may block the break down and absorption of starch in the intestine, although there is no scientific evidence that this causes weight loss. Again, the effects of these products may help you feel full and not hungry.

A more affordable, and possibly safer option would be to take a dietary fiber supplement such as methylcellulose (Citrucel©), psyllium, inulin (Fiber Choice©), or wheat dextrin (Benefiber©). These products are an easy way to add healthy fiber to your diet. Each of these come in different forms including tablets, capsules, chewable tablets, or powder that is mixed with water. You may need to try different types of fiber supplements such as those listed above to find the one that works best for you.

These “gut-fillers” and dietary fiber supplements have similar side effects including bloating, gas, diarrhea, constipation, and/or increased bowel movements. If your body is not used to digesting so much fiber, these products can cause loose stools which could lead to feeling hungry more often.

Once your body becomes accustomed to increased fiber, side effects usually decrease, you will notice your bowels become more regular, and your appetite may decrease. It is important to drink a large glass of water with any fiber supplement so that it can work properly and you do not become constipated.

Some natural ways to get the same effect of the above supplements include eating oatmeal, Cheerios©, or glucomannan pasta. Oats (contained in Cheerios©) increase the thickness of the contents of the stomach which leads to delayed absorption of food and feeling full longer.

Because of this effect, oats can decrease the absorption of cholesterol in the gut. Drinking plenty of water and snacking on fresh cut vegetables throughout the day can also keep your stomach feeling full and not hungry. Some other foods that are high in fiber include: oat bran, barley, peas, beans, wheat bran, whole grain rice, popcorn, cabbage, beets, carrots, celery, brussel sprouts, turnips, cauliflower, and prune juice.


Alli© (orlistat) is the only FDA-approved non-prescription weight loss aid. It decreases the amount of fat absorbed when eating. This causes a decrease in the number of calories your body absorbs after a meal. After one year of use, most people lose an average of about three to 10 pounds in addition to weight loss from diet and exercise.

Lipase, an enzyme found in the digestive tract, helps break down fat from food we eat into smaller components so that it can be used or stored for energy. Alli© works by disabling lipase, which prevents the enzyme from breaking down the fat while it’s in your digestive tract.

The undigested fat continues through the intestines and is eliminated through bowel movements. Alli© is taken with fat-containing meals, up to three times a day. Because of how Alli© works, it’s recommended that you eat no more than 15 grams of fat with each meal.

Alli© may cause decreased absorption of some vitamins, so it is important to take multivitamins two hours before taking Alli© or at bedtime. Other side effects may include loose stools, frequent stools, oily anal discharge, and/or gas. Eating more than 15 grams of fat per meal can make these side effects worse.

Taking psyllium (Metamucil©) fiber supplements while taking Alli© may help decrease these side effects. For safety reasons, people with gallbladder disease, digestive absorption problems, serious liver disease, and pregnant women should not take Alli©.

Green Tea Extract

Green tea is often steeped in hot water and consumed as a beverage. The extract form is concentrated green tea leaves usually put into capsules.

It is thought that green tea extract rich in the antioxidant EGCG (epigallocatechin gallate) may suppress the appetite and increase metabolism. Studies show that it may modestly improve weight loss when added to diet and exercise, although its efficacy is significantly increased when used in combination with caffeine.

Green tea extract can cause nausea, heart palpitations, shakiness, nervousness, insomnia, increased heart rate and increased blood pressure. People with uncontrolled high blood pressure, heart disease, or heart rhythm problems should avoid green tea extract for safety reasons.

Hoodia gordonii

Hoodia gordonii is a cactus-like plant that was supposedly used in Africa by hunters to stave off hunger while on long hunting trips. There are no scientific published studies on the use of Hoodia for weight loss, so it is largely unknown whether or not it is safe or effective.

Buyer beware! News reports suggest that some samples of hoodia products sold on the Internet do not contain any actual hoodia in them. It was so widely marketed that the demand outweighed the possible supply of plants. For these reasons, Hoodia is not recommended as a weight loss aid.

What is the bottom line when buying herbal or natural supplements for weight loss?

  • The manufacturers of supplements are not required to prove safety or efficacy (that it actually works) to the FDA or any other regulatory agency before they sell them.
  • Weight loss supplements often contain a cocktail of ingredients including multiple herbs, botanicals, vitamins, minerals, and add-ons such as caffeine or laxatives. It may be better to choose single-entity products.
  • If it sounds too good to be true – it probably doesn’t work. Those reporting “miraculous” results are most likely trying to sell you something.
  • There is no quick fix. The most effective way to begin and maintain weight loss is through reducing calories and increasing physical activity.
  • If you decide to start a dietary supplement for weight loss, please be sure to discuss it with your doctor, pharmacist, or health care provider so they can review the list of ingredients for side effects and potential interactions with other medication you may take.

About the Author:

Dr. Rachael Boggs is a clinical pharmacy specialist who works at University of Colorado Hospital. She completed pharmacy school at the University of Florida and an ambulatory pharmacy residency with the Veterans Affairs Health System. She moved to Colorado in 2011 where she provides clinical review of high-cost medications and focuses on wellness initiatives for the University of Colorado employee health plans.