Everything You Should Know About Weight Loss Supplements


If you’re trying to lose weight, you’re not alone: almost half of adults in the US did the same from 2013 to 2016. Women took the lead, with 56.4% of them saying they tried to shed pounds during that time. Over 40% of men also did the same.

Exercising and eating less were (and still are) the most preferred ways to lose weight. Almost a third of adults reported both as part of their regimen to slim down.

What if you’ve done the same, but your bathroom scale doesn’t show lower figures? Can weight loss supplements help?

To help you answer this question, we’ve come up with this guide about weight loss supplements. Read on to learn what they are, what science has to say about them, and which ones are safe to try.

What Are Weight Loss Supplements?

Weight loss supplements are also often called weight loss pills or diet pills. That’s because many of these products do come in pill form. Many are over-the-counter items, while some require a doctor’s prescription.

In any case, weight loss supplements are oral products marketed to help reduce weight. They contain ingredients that may do one of the following:

  • Help curb appetite
  • Minimize fat absorption
  • Boost the body’s fat-burning ability

Some products also have components that may perform a mix of those tasks. For example, one ingredient may help curb hunger, while another is for fat burning.

Do Weight Loss Pills Work?

This depends on the pills’ primary ingredients, as some studies have shown that they may help in some way. However, it’s vital that you stick to products that have scientifically tested ingredients. These are the components that studies have shown to help slash off some of those extra pounds.

Let’s take a look at some of these weight loss pill ingredients and their safety.


Caffeine is a natural compound found in plain and herbal coffee, tea, and dark chocolate. You’ll also find it in energy drinks and many baked goods. It’s a proven booster of metabolism, which is why a lot of weight loss supplements contain it.

How Does It Work?

As a metabolism booster, caffeine stimulates the central nervous system. It appears to speed up the number of calories that the body burns after ingesting it.

Caffeine also appears to boost your body’s energy use even while you’re resting. In doing so, it may promote thermogenesis. This is the process in which the body generates heat and energy from food that you’ve eaten.

Caffeine may also help reduce your feelings of hunger for a short period. In this way, you may feel like you don’t want to eat, so if you don’t, then that means you reduce your calorie intake.

One short-term study found that caffeine can raise metabolism by at least 3% to 4%. Participants who took caffeine also expended more energy (between 79 and 150 kcal). As such, the researchers conclude that caffeine may be helpful in treating obesity.

Another study also looked at the weight loss effects of caffeine from green tea. At the end of the study, the researchers found that participants lost 13 pounds.

Safety and Side Effects

For most adults, caffeine is safe at doses of between 400 and 500 milligrams (mg) per day. It can make you feel jittery, shaky, and nervous in higher amounts, though. It may also impair your sleep, so be sure not to take too much of it at the end of the day.

Green Coffee Bean Extract

Green coffee beans are coffee beans that haven’t undergone the roasting process. That’s because roasting minimizes the amount of chlorogenic acid (CGA) in the beans. As such, green coffee bean extract contains more of this compound than the roasted beans.

Green coffee bean extract also contains caffeine.

The Role of Chlorogenic Acid in Weight Loss

The chlorogenic acid in green coffee seems to affect the body’s metabolism process. One way it may do so is through its hypolipidemic effect, which may boost fat metabolism. It may also have a lowering effect on cholesterol and blood sugar levels.

As a bonus, CGA’s potential benefits on glucose may be useful against type 2 diabetes. It may also be helpful in a variety of memory-related conditions.

In human studies, CGA consumption has led to a greater weight loss effect than instant coffee. For example, in one long-term study, those who took CGA-rich coffee lost an average of almost 12 pounds. By contrast, those who drank instant coffee only lost an average of 3.74 pounds.

Safety and Side Effects

Green coffee bean extracts appear to be safe at doses of up to 200 mg a day. Make sure you don’t take in too much extra caffeine, though, as these already have some of it. As mentioned above, high doses of caffeine may make you feel jittery or nervous.


Glucomannan is a natural dietary fiber extracted from elephant yam (konjac) roots. You may have already encountered this ingredient in shirataki noodles and pasta. Diet pills are the most common products that use this weight-loss compound, though.

How It Works

As a dietary fiber, glucomannan absorbs water and transforms into a gel-like compound. So, when you take such weight loss supplements, the glucomannan in them will suck in some of the water in your gut. It “sits” there and can make you feel as if you’re still full and not ready to eat yet.

Because it promotes a feeling of fullness, you may find yourself eating less. This, in turn, may help you trim your calorie intake.

Studies do exist on glucomannan, the results of which found it to be effective in weight loss. In one study, the researchers noted an average loss of 1.76 pounds per week. The study, however, took five weeks, which means that the participants lost about 8.8 pounds in total.

Moreover, glucomannan may also help lower total and even bad cholesterol levels. It also appears to reduce triglycerides and blood sugar levels. These effects may then be helpful in folks who have high cholesterol and diabetes.

Safety and Side Effects

Most forms of glucomannan appear to be safe at doses of up to 15 g a day. This applies to weight loss supplements that are in either capsule or powder form.

One thing to note, though, is that it may cause loose stools and flatulence. In some people, constipation may also be a side effect.

Green Tea Extract

Did you know that the world produces millions of tons of green tea each year? That makes it one of the most common and popular types of teas around!

Green tea is so widespread not only because it’s delish, but also because it’s rich in antioxidants. This alone, according to scientists, may help boost heart, brain, liver, and even skin health.

More than that, green tea extracts also seem to aid weight loss via its caffeine and catechin content.

What Is Catechin?

Green tea, aside from caffeine, also has catechin, which is a flavonoid and an antioxidant. Researchers believe that these two compounds may help speed up the body’s metabolism.

Catechin, for starters, appears to break down excess fat. Both catechin and caffeine, on the other hand, raises the amount of energy used by the body.

Green tea extract comes from the green tea plant, but it’s a concentrated form of the drink version. As such, one capsule of this weight loss supplement should have the same ingredients as a cup of green tea.

Several studies found that the consumption of green tea may help aid weight loss. In one study, for instance, female participants took a daily dose of 856.8 mg of the extract. After twelve weeks, they had considerable weight loss and lower LDL cholesterol levels.

Safety and Side Effects

Even at the high dose of 856.8 mg per day, the participants had a good tolerance for green tea extract. As always, though, it’s best to minimize caffeine intake if you plan to use this diet pill. It contains some caffeine, so you may notice the side effects related to this stimulant.


L-carnitine is a compound that the body derives from amino acids. The body does produce a natural version of this, as it plays a role in turning fat into energy. It’s also vital for various heart, brain, and even muscle functions.

L-carnitine’s role in converting fat into energy is one reason for its use in weight loss pills.

How Does It Work?

In theory, L-carnitine weight loss pills may help boost the body’s fat-to-energy conversion. This idea stems from the fact that the amino acid derivative does transport fats into cells. From here, the body should then burn the fatty cells to provide you with usable energy.

Some researchers did find L-carnitine supplements to aid in weight loss. Note, though, that most participants in these studies had obesity. Since obesity changes the body’s structure, then L-carnitine may not work for everyone.

On the bright side, other L-carnitine studies showed that it might help counter obesity. It helped reduce the overall weight of patients who were overweight or who had obesity.

Safety and Side Effects

L-carnitine supplements appear to be safe at doses of up to 2 g per day. Some side effects may include nausea and cramps, especially if taken in higher doses. Other people have reported vomiting due to higher-than-directed intake.

Some people who have low L-carnitine supplies may benefit more from supplements. These include folks out there who mostly eat plant-based meals.

Orlistat (Alli)

Orlistat is a pharmaceutical product that you can buy over-the-counter in the form of “Alli.” It also has a prescription version called “Xenical”.

Orlistat works by hampering the body’s ability to break down the fat in the gut.

Sounds counterintuitive, doesn’t it? However, in inhibiting fat breakdown, it may make you consume fewer calories from fat.

How Effective Is It?

There’s a lot of big studies done on Orlistat, seeing as it’s also available as a prescription. A review of 11 studies found that it can help boost the results of a weight loss program. The researchers found that, on average, it can increase weight loss by at least 6 pounds.

Moreover, Orlistat may also have a slight effect on lowering blood pressure. In another study, the researchers found that it may also help cut the risk of type 2 diabetes by 37%.

Safety and Side Effects

The most common side effects of Orlistat affect the digestive system. These include loose stools, oily stools, and flatulence. It’s also common for those who take these diet pills to see an increase in the frequency of bowel movements.

Boosting the Results of Your Weight Loss Plan

The proven ways to slim down are healthy, mindful eating, and physical activities. Moreover, these two practices are also the most natural ways to lose weight. They also do more than help you shed pounds: they also improve your overall health and well-being.

In many cases, though, you may find that weight loss supplements can help you see results a bit faster. In this case, you may want to introduce diet pills alongside your healthy veggies and greens. In this way, you may be able to reduce calorie and fat intake and also speed up your metabolism.

Don’t forget to exercise or at least to move more and reduce your sedentary behavior. For example, instead of taking the elevator or escalator, you may want to go up and down the stairs. During your breaks, consider taking walks, which may even help you counter stress.

Always Prioritize Your Safety When Taking Weight Loss Pills

There you have it, your ultimate guide on weight loss supplements and diet pills. Now, you know which ones have undergone scientific tests and what science has to say about them. So, as much as possible, you should stick to these products with research to back them up.

Most importantly, consult your doctor first if you plan to take weight loss pills. Also, be sure not to forget to follow the directions on each of these products’ labels.

Interested in learning more about weight loss products? Then please feel free to check out our extensive selection of dietary supplements! We also have loads of other health guides, so don’t be shy to read as many of them as you want.