There are numerous supplements on the market that claim to help with weight loss. Some might work, some might not, and others are in need of more research.

Losing weight can be a daunting task. If you think diet and exercise alone aren’t cutting it, you might look to supplements to enhance your efforts.

But you may wonder whether weight loss supplements are safe and actually work to help you lose weight.

This article will detail how some weight loss supplements work, how safe and effective they are, and what people who have used them say about them. All this can help inform your decision making and prepare you for conversations with healthcare professionals before using weight loss supplements.

Weight loss supplements contain active ingredients — such as fiber, herbs, and minerals — that target your body’s metabolism, fat absorption, and satiety. You may find supplements in tablet, liquid, and powder forms.

There are many supplements on the market, and each has its own claims and potential benefits with regard to weight loss.

The National Institutes of Health (NIH) points out that only some supplements are supported by research.

Can help weight lossNot enough evidenceLikely doesn’t help
African mango
conjugated linoleic acid
green coffee bean extract
green tea and extract
bitter orange
Coleus forskohlii
• probiotics
raspberry ketones
beta glucan
• calcium
garcinia cambogia
guar gum
• vitamin D

As the main medical research agency in the United States, the NIH makes important discoveries and publishes countless research articles each year to help people make decisions to benefit their health.

The NIH details the claims behind each of the above weight loss supplements and whether research supports those claims.

Here’s a look at what people who have used certain weight loss supplements say about the products they have used. These three weight loss supplements were chosen because they contain ingredients that have some scientific backing, they have customer reviews, and they have relatively mild side effects.

alli (Orlistat)

alli is the only weight loss supplement approved by the Food and Drug Administration. It contains the active ingredient orlistat. This product works by preventing your digestive tract from absorbing up to 30% of the fat you eat. Any undigested fat exits your body through feces.

Research suggests that by combining this supplement with a low calorie diet, people may be able to lose 5–10% of their starting weight. The supplement also appears to help people keep the weight off over time.

The manufacturer of alli recommends it for use in adults over 18 with a BMI of 25 or higher. Possible side effects include bloating, diarrhea, oily discharge, and flatulence.

Cost: $66.50 for 120 capsules

What people say about Orlistat

Amazon: 4.2 out of 5 stars

Dani shares: “With diet and exercise and these pills, I have managed to lose and keep off 30 pounds over the course of three and a half months. The key [is including] diet and exercise. I’m not just taking these pills hoping that … they are just going to make me lose weight without having to put in any work.

“There are some side effects … [I]f you consume too much fat in a meal, you may run into some [digestive] side effects. I have found this to be true.”

Stripfast5000 Fire Bullets with K-CYTRO

This Amazon bestselling supplement relies on high caffeine content to promote weight loss. Its active ingredients include green tea, raspberry ketone extract, cayenne pepper, and green coffee extract.

According to the NIH, caffeine may boost your energy levels, increase your calorie burn, and help your body break down fat. And green coffee extract, green tea, and caffeine may help you lose a small amount of weight. Green coffee extract, specifically, may reduce fat and help your cells use blood sugar for energy.

This supplement is for people over 18 and is not suitable for people who have a sensitivity to caffeine, are pregnant or nursing, or have high or low blood pressure.

Cost: $37.90 for 60 pills

What people say about StripFast5000 Fire Bullets

Amazon: 4.9 out of 5 stars

Ariana shares: “I started seeing results in the first week. When I put my pants on, they were not super tight on the stomach. Then I started not feeling so hungry and had so much energy that I started going back to the gym and got so much muscle.

“If you want to lose weight, just give this a try. Just make sure to drink tons of water.”

NaturaLife Labs Acetyl L-Carnitine 1,500 mg

L-carnitine is another ingredient with research to support its weight loss claims. Your body actually makes carnitine, and it’s found naturally in foods such as dairy products, fish, and poultry.

L-carnitine works by supporting fat metabolism in your body. According to the NIH, it may help people lose a small amount of weight. With regard to safety, dosage matters. Adults can safely take up to 2,000 milligrams per day for 1 year.

Possible side effects include stomach upset, nausea, vomiting, and diarrhea. You may also notice a foul, fishy body odor when using this supplement.

Cost: $17.00 for 100 capsules

What people say about NaturaLife Labs Acetyl L-Carnitine 1,500 mg

Amazon: 4.5 out of 5 stars

Recom_48221 shares: “I’ve been struggling with trying to lose weight for several years and was at a stuck-point. I added the Acetyl L-Carnitine to a 10-day detox regimen after reading about its effectiveness as a weight loss aid. I ended up losing a total of 15 pounds with the use of Acetyl L-Carnitine. I definitely credit my use of this product for the success.”

The amount of time it takes for a supplement to work depends on the supplement and various factors unique to your overall health. Taking supplements along with other lifestyle measures, such as diet and exercise, may help you lose weight more quickly.

For example, using alli, you can expect to lose weight each week. For every 2 pounds you lose with diet and exercise, you may lose an additional 1 pound from the supplement alone. Over 6 months, most people lose 5–10 pounds total.

Side effects will depend on the active ingredients in the supplement you choose. Read labels carefully and discuss any concerns with a pharmacist or another healthcare professional.

It’s a good idea to make an appointment with a healthcare professional to discuss taking over-the-counter supplements, the possible side effects of these products, and any interactions they may have with medications you’re taking.

If you’re trying to lose weight, consider making an appointment with a healthcare professional. They may suggest a diet or exercise program that can help you reach your goals. If you’re looking for an extra edge, a healthcare professional can also discuss weight loss supplements, prescription drugs, and surgical options that might make sense for your health and lifestyle.