The Dietary Supplements that are Most Helpful for Obesity and Weight Loss

There are so many dietary supplements and natural remedies available for weight loss. It can be really hard to know which ones to take. Which ones actually work? Are any of them dangerous?

Let me start by saying that as a scientist and nutritionist, I cannot recommend very many dietary supplements for obesity and weight loss. There are a few, so definitely keep reading. But, I can’t recommend very many because – and I need you to read this carefully – the dietary supplement industry is not well regulated. Which means dietary supplements can be dangerous.

A warning about dietary Supplements

The Dietary Supplements Health and Education Act (DSHEA) that was passed in 1994 says there is no requirement for dietary supplements to go through any pre-approval to ensure they are safe or effective before they go to market. This means the supplement can have something in it that is not on the label, and it can also mean it does not have the amount of active ingredients it says it has on the label.1

The US Food and Drug Administration (FDA) can only intervene to protect consumers from poor quality supplements after the supplement has entered the market, and usually because of an adverse event report. In other words, after something bad happens and the damage is already done. For more information about DSHEA and dietary supplement regulations, you can read more on the FDA’s website.1

Supplements specifically made for weight loss, sexual enhancement, and body building are likely to be intentionally contaminated with pharmaceutical-grade compounds. Such compounds may not necessarily be FDA-approved or in the right dose for you. And, of course, your doctor will not know you are taking them because you don’t even know you are taking them!2

Dietary supplements across the board are also often contaminated with toxic heavy metals. And, they are more likely to have bacterial contamination. Finally, they do not necessarily have the dose they report on the label, and they sometimes contain an alternative for the herb they claim to contain.2

Are any of them tested?

Even though there are reasons to be careful, there are several ways to find a safe, quality source of dietary supplement. Some third-party services verify the safety and quality of dietary supplements.

One is Labdoor. They test specific supplements to see if they have the ingredients they say they do, in the amounts on the label, and if they contain anything else. They then publish a summary report of what they find that you can check.

Another service is offered by the United States Pharmacopeia. They also have a verification program for supplement companies that adhere to their standards for quality and safety. If a supplement has gone through their program, it has a "USP verified" symbol on the label. And you can easily search for supplements that have passed the test.

Which supplements are safe and helpful?

Here are some supplement ingredients that are well tested, safe, and likely helpful supplements to consider. Most of these either support an active lifestyle, ensure your nutritional health while on a lower calorie diet, or help with weight loss and maintaining a lower calorie diet. So if you can find a company that manufactures them safely, you may consider asking your doctor about taking them.


Caffeine has several benefits to support more intense physical activity. It can also help to suppress appetite if you are working on not overeating or following a lower calorie diet.3,4

Common side effects include feeling jittery, feeling anxious, and sleep loss. The effectiveness of caffeine depends on a few factors, and the right dose must be taken at the right time for it to be helpful. It is most effective if you haven’t had caffeine for a while, because you may build up tolerance to it.


Anyone following a diet that is considered a “very low calorie diet” (VLCD) for longer than 2 weeks should consider a multivitamin supplement. It can be hard to get enough micronutrients when eating much less food than normal. In general, VLCDs should only be followed under medical supervision. Your doctor may advise a multivitamin supplement depending on how long you will be following a VLCD or what your food sources are while on the VLCD.

Iron supplements

Iron deficiency is more common among frequent dieters, among people with obesity, and women. If you have obesity and diet frequently, is a good idea to get your iron levels checked. Getting enough iron through your diet can be a challenge especially when reducing calorie intake for weight loss and if you follow a vegan or vegetarian lifestyle. In some cases, iron supplementation and working on a balanced diet can help support your health and an active lifestyle.5,6

Protein supplements

Protein is filling, and taking enough protein during weight loss helps to maintain muscle mass. Most studies that find benefit study protein intake of 1 to 1.5 grams of protein per kilogram of body weight per day. If you are reducing calories for weight loss, it can be hard to get enough protein. Lean sources of protein like egg whites, chicken and fish help. But protein supplements can also be very convenient and helpful to achieve this higher protein intake.7

Fiber and other calorie diluters

Some fibers and calorie diluters have been tested for their ability to reduce body weight. Calorie diluters work by "diluting" the calories in your food so you feel fuller even when eating less food. The 2 with some evidence behind them are chitosan, which is a fiber isolated from shells, and glucomannan, a fiber from roots of the konjac plant. Keep in mind, these supplements by themselves only produce 1 to 2 kgs of weight loss, and they may need to be paired with other strategies if you need to lose more than that.8

Supplements may support weight management

So, there can be a role for some supplements in supporting your weight management and health. It is very important to find a quality source of supplement. And be sure to check with your doctor before taking any dietary supplement.

This article represents the opinions, thoughts, and experiences of the author; none of this content has been paid for by any advertiser. The team does not recommend or endorse any products or treatments discussed herein. Learn more about how we maintain editorial integrity here.

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